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This study investigated the influences of explosive quadriceps strength and landing task on sagittal plane knee biomechanics. Forty female participants performed isometric knee extensions on a dynamometer and had lower extremity biomechanics assessed during double-leg jump-landings (DLJL) and single-leg jump-cuts (SLJC). Explosive quadriceps strength was quantified by calculating rate of torque development (RTD) between torque onset and 100 ms after onset on a dynamometer. Participants were stratified into high and low RTD groups. Landing biomechanics were compared using 2 (Group) × 2 (Task) mixed-model ANOVAs. The relationships between quadriceps RTD and landing biomechanics were also assessed using simple, bivariate correlations. Across RTD groups, greater knee flexion at initial contact (KFIC), peak vertical ground reaction force, peak anterior tibial shear force, and peak internal knee extension moment, and lesser peak knee flexion was observed during SLJC compared to DLJL. The high RTD group exhibited significantly greater KFIC than the low RTD group across landing tasks. Greater quadriceps RTD was significantly associated with greater KFIC during SLJC, but not during DLJL. As landing with lesser KFIC is a risk factor for ACL injury, greater explosive quadriceps strength capacity might be beneficial for facilitating the use of safer landing mechanics during athletic tasks.

Context Emerging evidence suggests that a lower quadriceps rate of torque development (RTD) after anterior cruciate ligament (ACL) reconstruction (ACLR) may be associated with altered landing mechanics. However, the influence of quadriceps RTD magnitude and limb symmetry on landing mechanics limb symmetry remains unknown. Objective To assess the influence of quadriceps RTD magnitude and limb symmetry on limb symmetry in sagittal-plane landing mechanics during functional landing tasks in females with or without ACLR. Design Cross-sectional study. Setting Laboratory. Patients or Other Participants A total of 19 females with ACLR (age = 19.21 ± 1.81 years, height = 164.12 ± 6.97 cm, mass = 63.79 ± 7.59 kg, time after surgery = 20.05 ± 9.50 months) and 19 females serving as controls (age = 21.11 ± 3.28 years, height = 167.26 ± 7.26 cm, mass = 67.28 ± 9.25 kg). Main Outcome Measure(s) Landing mechanics were assessed during a double-legged (DL) jump-landing task, a single-legged jump-landing task, and a side-cutting task. Quadriceps RTD was collected during isometric muscle contractions. Separate stepwise multiple linear regression models were used to determine the variance in limb symmetry in the sagittal-plane knee moment at initial contact, peak vertical ground reaction force, and loading rate that could be explained by quadriceps RTD magnitude or limb symmetry, group (ACLR or control), and their interaction. Results In the ACLR group, greater limb symmetry in quadriceps RTD was associated with greater symmetry in sagittal-plane knee moment at initial contact during the DL task (P = .004). Peak vertical ground reaction force and loading rate could not be predicted by quadriceps RTD magnitude or limb symmetry, group, or their interaction during any task. Conclusions Developing greater symmetry but not magnitude in quadriceps RTD likely enabled more symmetric sagittal-plane knee landing mechanics during the DL task in the ACLR group and thus may reduce the risk of a second ACL injury. Such a protective effect was not found during the single-legged or side-cutting tasks, which may indicate that these tasks do not allow for the compensatory landing mechanism of shifting load to the uninvolved limb that was possible during the DL task.

Athletic taping is widely used in sports to prevent injury. However, the effect of anterior cruciate ligament (ACL) protective taping on neuromuscular control during dynamic tasks remains unclear. Therefore, this study aimed to investigate the immediate effect of ACL protective taping on landing mechanics and muscle activations during side hops in healthy individuals. Fifteen healthy individuals (11 males and 4 females, age, 23.1 ± 1.4 years, height, 175.1 ± 10.4 cm, weight, 66.3 ± 11.2 kg) volunteered to participate in this study. Landing mechanics and muscle activations were measured while each participant performed single-leg hops side-to-side for ten repetitions with and without taping. An optical motion capture system and two force plates were used to collect the kinematic and kinetic data during the side hops. Surface electromyogram recordings were performed using a wireless electromyography system. Paired t-tests were performed to determine the differences in landing mechanics and muscle activations between the two conditions (taping and non-taping). The level of significance was set at p &lt, 0.05. Compared with the non-taping condition, participants landed with a smaller knee abduction angle, greater knee external rotation angle, and smaller knee extensor moment in the taping condition. Given that greater knee abduction, internal rotation, and knee extension moment are associated with a greater risk of ACL injury, our findings suggest that ACL protective taping can have an immediate effect on dynamic knee stability. Clinicians should consider using ACL protective taping to facilitate the use of favorable landing mechanics for ACL injuries.

Background: Anterior cruciate ligament (ACL) injury prevention programs (IPPs) are generally accepted as being valuable for reducing injury risk. However, significant methodological limitations of previous meta-analyses raise questions about the efficacy of these programs and the extent to which meeting current best-practice ACL IPP recommendations influences the protective effect of these programs. Purpose: To (1) estimate the protective effect of ACL IPPs while controlling for common methodological limitations of previous meta-analyses and (2) systematically categorize IPP components and factors related to IPP delivery to assess the validity of current best-practice IPP recommendations. Study Design: Systematic review with meta-analysis. Methods: A systematic search of 5 electronic scientific databases was conducted to identify studies testing the efficacy of ACL IPPs. Studies were included if (1) the intervention aimed to prevent ACL injury, (2) the incidence rate (IR) or other outcome data that made it possible to calculate the IR for both the intervention and control groups were reported, and (3) the study design was a prospective randomized controlled trial (RCT) or cluster-RCT. Results: Of the 2219 studies screened, 8 studies were included in the quantitative synthesis, and their analysis revealed a significant reduction in ACL IR when athletes received IPPs (IR ratio = 0.47; 95% CI, 0.30-0.73; P < .001). The majority of included IPPs tended to meet minimum best-practice recommendations and incorporated plyometric, strengthening, and agility exercises along with feedback on proper landing technique. However, the specific exercises included in each IPP and key factors related to IPP delivery were highly variable. Conclusion: Despite limiting the analysis to only high-quality studies and controlling for time at risk and potential clustering effects, the study showed that ACL IPPs had a significant protective effect and reduced injury rates by 53%. However, significant variability in the specific exercises and the manner of program delivery suggests that ACL IPPs may be able to be designed within an overarching best-practice framework. This may allow practitioners the flexibility to develop IPPs that meet the specific characteristics of the target population and potentially increase the likelihood that these programs will be widely adopted and implemented.

The modern e-learning environment generates new types of students’ learning records, including their operation records in the learning management system. Recently, wearable devices and a variety of sensors have become common in our daily life. By using these devices, we can access students’ information such as heart rates and facial features. Previous studies [1, 2] have used the bioinformatics data mentioned above to analyze students’ learning effectiveness. However, these approaches only utilize partial information and the diversity of data has not been put into consideration. This paper tries to better address this inefficiency by proposing an Analytic Hierarchy Process (AHP)-based model integrated with professional expertise in education. With this model, lecturers can customize the selection and importance of the criteria according to the used teaching strategy. Then, AHP4Edu can analyzes students’ learning effectiveness scores from the sub-scores of the sub-criteria specified by an expert or a lecturer. We present simulations on assessing students’ learning effectiveness for distance learning. We also demonstrate how AHP4Edu integrates heterogeneous data and provides a reliable learning effectiveness assessment for the lecturer.

Lower explosive quadriceps strength, quantified as rate of torque development (RTD), may contribute to landing mechanics associated with anterior cruciate ligament (ACL) injury risk. However, the association between quadriceps RTD and landing mechanics during high demand tasks remains unclear. Therefore, this study investigated the influence of quadriceps RTD on sagittal plane landing mechanics during double-leg jump landings (DLJL) and single-leg jump cuts (SLJC) in females with and without ACL reconstruction (ACLR). Quadriceps RTD was measured during isometric muscle contractions. Landing mechanics were collected during DLJL and SLJC tasks. Separate stepwise multiple linear regression models determined the amount of variance in sagittal plane landing mechanics that could be explained by quadriceps RTD, group (ACLR or Control), and their interaction. The results indicate that greater quadriceps RTD is associated with lower loading rate (p = 0.02) and longer time to peak vertical ground reaction force (p = 0.001) during SLJC, regardless of ACLR status. As greater loading rate may lead to higher risk of ACL injuries and post-traumatic knee osteoarthritis post-ACLR, explosive muscle strength interventions might be useful for individuals with and without ACLR to facilitate the use of safer landing mechanics.

Background and objectives: Anterior cruciate ligament reconstruction (ACLR) often results in quadricep atrophy. The purpose of this study was to compare the bilateral thickness of each quadricep component before and after ACLR. Materials and Methods: Cross-sectional study design. In 14 patients who underwent ACLR, bilateral quadricep muscle thicknesses were measured using a portable ultrasound device, 1 h before and 48&ndash, 72 h after ACLR. Two-way analysis of variance (ANOVA) was used to compare muscle thickness pre- and post-ACLR between the limbs. Results: The primary finding was that the vastus intermedius (VI) muscle was significantly smaller in the reconstructed limb after ACLR compared to that in the healthy limb (Reconstructed limb, RCL = Pre-operated (PRE): 19.89 &plusmn, 6.91 mm, Post-operated(POST): 16.04 &plusmn, 6.13 mm, Healthy limb, HL = PRE: 22.88 &plusmn, 6.07, POST: 20.90 &plusmn, 5.78 mm, F = 9.325, p = 0.009, &eta, 2p = 0.418). Conclusions: The results represent a selective surgical influence on the quadricep muscle thickness. These findings highlight the need of advanced strengthening exercises in order to restore VI thickness after ACLR.

In this work, a very large scale integration chip for arrhythmia detection is proposed. The proposed chip comprises a convolution neural network (CNN) for detecting the abnormal heartbeat of premature ventricular complex (PVC) by using 4-lead electrocardiogram signals. The proposed CNN comprised two convolution layers and one fully connected layer to achieve high-accuracy PVC detection. The detection accuracy of the proposed CNN circuit was 94.94% when implemented in a single chip using TSMC $0.18-\mu\ \mathbf{m}$ complementary metal-oxide-semiconductor processing techniques. The results indicated that the proposed core consumes 3.1-mW power with a clock frequency of 66.6 MHz, and the gate count of the proposed core was 14 K. Thus, the proposed CNN offers high speed, a small area, and high-accuracy PVC detection.

To assist in the automation of factory processes, the amount of valuable data flow in the industrial cyber-physical system (CPS), Internet of things (IoT) and cloud computing will also have to increase accordingly. Thus, developing a risk assessment system which is specialized for an industrial IoT system is necessary, especially for the cloud platform that the data mainly flow on. In this paper, we revise the AHP (Analytic Hierarchy Process) method and propose a 3-layer AHP-based risk assessment model (3aRAM) for an Industrial IoT cloud (PaaS platform) to allow the cloud system to self-benchmark its own security status. The model is composed of three phases: data collection, data analysis and risk assessment. To refrain from unnecessary experts involving into the risk assessment phase, a feedback mechanism is designed in the proposed model. We realize the risk assessment system and apply it to an industrial IoT cloud system. Finally, we estimate the practicality of our system by injecting different degrees of noises and launching DoS attacks, and show the change of integrity and availability scores, which are generated by the proposed risk assessment model.

An Industrial Internet-of-Things (IIoT) Cloud builds up a platform to accelerate the realization of factories running Industry 4.0 services. The IIoT cloud interconnects machines, robotic arms, controllers and drivers to form a collaborative platform [1], which brings the convenience of developing new features, for example, remote controlling, automatic producing, etc. However, the interconnected network may suffer from new security issues and risks. Hence, a method for assessing risks of the IIoT network is required, especially for the core running cloud services for the IoT devices. In this research, a novel AHP (Analytic Hierarchy Process) [2]-based risk assessment model is presented for an IIoT cloud to self-check its own health.

As "working with a browser" continues to gain acceptance, an emerging strategy adopted by software companies is to provide a Web version of their applications previously developed in a desktop environment. This article introduces a desktop application service framework that enables a Web server to host desktop applications and supports accessing these applications through a browser. The authors present a case study to show how the framework helps a virtual desktop cloud reduce bandwidth consumption by supporting browser-based access.

In a high movement environment, handover occurs frequently in a mobile network and degrades the quality of mobile communication and service. The shorter the handover delay is, the better the communication quality can be obtained. To shorten the handover delay for a bunch of UEs moving in the same direction, mobile relays (MR), an intermediate role between a UE and an eNodeB (eNB), have been introduced to support mobile communication and service in a Long-Tern Evolution Advanced (LTE-A) network for high-speed rail systems. MR acts as an eNB for the UE, and acts as a UE for the eNB. Since a train travels along a fixed trajectory, target eNB are predicatible when handover is required. Based on such an assumption, we design an enhanced handover scheme to simultaneously synchronize the target eNB and complete the path switch among the serving eNB and target eNB. We run several simulations to show that the proposed scheme can shorten 29.63% of the handover delay.

When running smart living applications requiring intensive computing power in a cloud, a proper resource management algorithm is required to guarantee the performance of the applications. The paper presents a Genetic Algorithm (GA) based resource management algorithm, GASdv2, for allocating cloud-based virtual machines on physical machines. GASdv2 analyzes the utilization of hardware resources (CPU, memory, etc.) and generates an optimized distribution strategy to obtain better performance of the cloud running applications that requires intensive computing power and/or memory capacity.

This paper introduces an Embedded Software Architecture for Intelligent Robot systems (ESAIR) that addresses the issues of parallel thread executions on multi-core processor platforms. ESAIR provides a thread scheduling interface to improve the execution performance of a robot system by assigning a dedicated core to a running thread on the fly and dynamically rescheduling the priority of the thread. In the paper, we describe the object-oriented design and the control functions of ESAIR. The modular design of ESAIR helps improve the software quality, reliability and scalability in research and real practice. We prove the improvement by realizing ESAIR on an autonomous robot, named AVATAR. AVATAR implements various human-robot interactions, including speech recognition, human following, face recognition, speaker identification, etc. With the support of ESAIR, AVATAR can integrate a comprehensive set of behaviors and peripherals with better resource utilization.

Online social networks (OSNs) such as Facebook and MySpace are flourishing because more and more people are using OSNs to share their interests with friends. Because security and privacy issues on OSNs are major concerns, we propose a security framework for simultaneously authenticating multiple users to improve the efficiency and security of peer-to-peer (P2P)-based OSNs. In the proposed framework, three batch authentication protocols are proposed, adopting the one-way hash function, ElGamal proxy encryption, and certificates as the underlying cryptosystems. The hash-based authentication protocol requires lower computational cost and is suitable for resource-limited devices. The proxy-based protocol is based on asymmetric encryption and can be used to exchange more information among users. The certificate-based protocol guarantees nonrepudiation of transactions by signatures. Without a centralized authentication server, the proposed framework can therefore facilitate the extension of an OSN with batched verifications. In this paper, we formally prove that the proposed batch authentication protocols are secure against both passive adversaries and impersonator attacks, can offer implicit key authentication, and require fewer messages to authenticate multiple users. We also show that our protocols can meet important security requirements, including mutual authentication, reputation, community authenticity, nonrepudiation, and flexibility. With these effective security features, our framework is appropriate for use in P2P-based OSNs.

Virtualization is essential to cloud computing, yet its security vulnerabilities in the cloud environment haven't been sufficiently studied. This analysis of cloud security focuses on how virtualization attacks affect different cloud service models.

The authentication and key agreement (AKA) protocol of Universal Mobile Telecommunication System (UMTS), which is proposed to solve the vulnerabilities found in Global System for Mobile Communications (GSM) systems, is still vulnerable to redirection and man-in-the-middle attacks. An adversary can mount these attacks to eavesdrop or mischarge the subscribers in the system. In this paper, we propose a secure AKA (S-AKA) protocol to cope with these problems. The S-AKA protocol can reduce bandwidth consumption and the number of messages required in authenticating mobile subscribers. We also give the formal proof of the S-AKA protocol to guarantee its robustness.

Handover security and efficiency have become more and more important in modern wireless network designs. In this paper, we propose a new protocol using the one-time key for user authentication. The proposed protocol can support both intra-domain and inter-domain authentications efficiently. Our protocol requires five messages for intra-domain initial authentication; three for subsequent authentication; and five for handover authentication. No authentication server is needed during handover, and our design reduces the computing load on the authentication server. We show an integration and implementation of EAP from 802.1X and our protocol, giving an easy way to apply our protocol on existing 802.11 wireless networks. The proposed protocol is realized and verified on the SWOON secure wireless testbed.

This paper describes an approach for developing threat models for attacks on control systems. These models are useful for analyzing the actions taken by an attacker who gains access to control system assets and for evaluating the effects of the attacker’s actions on the physical process being controlled. The paper proposes models for integrity attacks and denial-of-service (DoS) attacks, and evaluates the physical and economic consequences of the attacks on a chemical reactor system. The analysis reveals two important points. First, a DoS attack does not have a significant effect when the reactor is in the steady state; however, combining the DoS attack with a relatively innocuous integrity attack rapidly causes the reactor to move to an unsafe state. Second, an attack that seeks to increase the operational cost of the chemical reactor involves a radically different strategy than an attack on plant safety (i.e., one that seeks to shut down the reactor or cause an explosion).

Modern obfuscation techniques are intended to discourage reverse engineering and malicious tampering of software programs. We study control-flow obfuscation, which works by modifying the control flow of the program to be obfuscated, and observe that it is difficult to evaluate the robustness of these obfuscation techniques. In this paper, we present a framework for quantitative analysis of control-flow obfuscating transformations. Our framework is based upon the control-flow graph of the program, and we show that many existing control-flow obfuscation techniques can be expressed as a sequence of basic transformations on these graphs. We also propose a new measure of the difficulty of reversing these obfuscated programs, and we show that our framework can be used to easily evaluate the space penalty due to the transformations.

As embedded systems are getting popular in industrial product designs, a dedicated teaching laboratory for embedded systems (EST Lab) has been setup for college and graduate students to get familiar with embedded system engineering and researches. In this paper, we present our experiences in embedded system education curriculum and teaching laboratory design carried out in the past few years. Accompanied by a series of courses with hands-on exercises, students can understand the whole picture of embedded systems in a more systematic way. To give students a comprehensive view of embedded systems, the curriculum includes not only embedded hardware architectures and operating systems but also embedded user-level software designs. We select the most popular and available open-source operating system, Linux 2.6, as the primary experimental platform for all laboratory practices. In addition to the course design, several research results derived from this laboratory are also presented in this paper.

This paper presents a secure capability-based access control model (S-CBAC) for a distributed IoT environment. S-CBAC supports group access which allows using a single token to access common services running on multiple devices. It also leverages IPsec to ensure end-to-end security and data privacy.

Although cloud computing technologies provide many advantages for organizations, security is still a barrier for wide-spread adoption to the public. Many cloud systems suffer from various attacks, including unauthorized data modification, denial of service, etc. The existing researches use risk assessments to evaluate the security of a cloud environment either from a CSP's viewpoint or from a user's point of view. The results of these works may not be precise enough, nor can they satisfy both CSP's and user's security requirements. We propose an Adjustable Cloud Risk Assessment systeM (ACRAM) for Cloud Service Providers (CSPs) and users to assess the cloud security. ACRAM consists of a risk assessment module running at two modes (Offline or Online mode) with the help of Security Service Level Agreement (SecSLA) signed by the CSP and the cloud user. The Offline mode is used for assessing the risk of a cloud based on the historical software vulnerabilities, while the Online mode is for assessing the risk of a cloud system at RUNTIME. To explain how ACRAM works for altering the potential threats in a cloud system, we conduct an experiment using different weights in Confidentiality (C), Integrity (I) and Availability (A). The results show that 1) CSP can protect future users from being co-located with a possible attacker, 2) CSP can take some risk mitigation to meet a user's requirements and keep the user from being attacked.

To provide secure media delivery in pay-TV systems, a large number of messages are exchanged for key updates in the conventional key distribution schemes. This is inefficient and costly when the client side (set-top box) uses a smart card with limited computing power. In this paper, we present three key distribution schemes for channel protection and secure media delivery in pay-TV systems. With the proposed schemes, encryption keys of the subscribed programs can be efficiently and securely distributed to the authorized subscribers. Only one message is needed to renew key in the key distribution schemes for subscription channel protection. In addition, we use simpler computation functions, including one-way hash function and exclusive-OR operation, for key updates to reduce the computation cost. With our key distribution schemes, only authorized subscribers can watch the subscribed programs correctly. Unauthorized subscribers have no information to retrieve the correct programs over the networks. Thus, service providers can charge their subscribers according to their subscriptions, and the illegal access of the media and video programs from networks can be prevented, based on the proposed schemes.

The (m,n) wireless information dispersal scheme (WIDS) is useful for fault-tolerant parallel wireless communications, where it can be used to tolerate up to n-m path (sub-channel) failures. This paper constructs a performance model of (m,n) WIDS used in wireless communications, and proposes an algorithm to find the optimal set of (m,n) with the highest reliability. This algorithm reduces the complexity of finding the candidate set of (m,n) from O(N/sup 2/) to O(N);N is the maximum number of available sub-channels.

We established a porcine model of ureteropelvic junction (UPJ) obstruction using a laparoscopic technique and assessed the outcome of standard suture-assisted and chemical glue-assisted laparoscopic pyeloplasty.Female domestic pigs (N = 20) underwent laparoscopic suture-ligature to create UPJ obstruction. One month later, laparoscopic end-to-end anastomosis was performed to correct the obstruction: with standard suturing techniques in 10 animals and with chemical (cyanoacrylate) glue in the other 10. Postoperative ureteral stents were not used. Four weeks postoperatively, intravenous urography was performed to evaluate the patency of the anastomoses. The UPJ was procured by laparotomy to assess the anastomoses and periureteral fibrosis histologically.The UPJ obstruction was created in an average of 15 +/- 6 minutes. There was no early postoperative mortality. Eighteen pigs survived for at least 1 month, and UPJ obstruction developed in 17 (95%). Microscopically, the lumen of the UPJ was partially occluded, measuring an average of 40% +/- 5% of normal. After laparoscopic correction, a patent UPJ was found in seven of nine animals treated with traditional sutures. Among the eight animals with chemically glued anastomoses, none had a patent UPJ, and severe periureteral adhesions and intraluminal fibrosis were noted at the pyeloplasty site. Marked ureteral tortuosity was present in six of the eight pigs receiving glue-assisted pyeloplasty but in none of the animals having suture-assisted pyeloplasty.Ureteropelvic junction obstruction was established by laparoscopic suture-ligature in a porcine model with a 95% success rate. Chemical glue-assisted anastomosis was inferior to standard laparoscopic sutures for pyeloplasty to correct the obstruction.

Objectives. To assess the expression rate of a cancer-related gene, hepatoma-up-regulated protein (HURP), in the tumor tissue of transitional cell carcinoma (TCC), and to assess the potential suitability of using this gene as a novel molecular marker for detecting TCC in voided urine. Methods. Total RNA was extracted from 80 TCC tissue samples of the urinary tract. Forty-five of the 80 tumor-adjacent tissue samples were from the same patients and 15 were from control subjects (patients with benign prostatic hyperplasia). The expression levels of HURP mRNA in these specimens were examined using reverse transcriptase-polymerase chain reaction. The HURP mRNA transcripts in voided urine pellets from 14 additional patients were determined using the same method. The messages were normalized to beta-actin mRNA. Results. The detection of HURP expression in the TCC tissue samples had a sensitivity of 88.8% (71 of 80) and a specificity of 100% (15 of 15). Ten of the 45 grossly tumor-adjacent tissue samples expressed HURP mRNA, which may indicate subtle genetic changes in tissue adjacent to tumor. All seven urine specimens from the patients with TCC revealed HURP expression; however, no specimens from patients with nonmalignant diseases did so. Conclusions. A potential molecular marker for detecting TCC with tissue specimens and voided urine samples has been found. Although the real clinical application of this marker requires additional evaluation, the high sensitivity and specificity of the HURP gene amplification method warrants more investigation in the future.

The paper is aiming at designing and implementing a real-time control platform for distributed motors. With the proposed design, experts can activate a monitor at a remote site, check the states of motor in real time and send proper control parameters to immediately control the motor via its controller. By leveraging the modern virtualization technologies, two designs are presented in the paper. We investigate the real-time performance of the host machine by executing stress test on the virtual machines. We also prove that the realization of our design can obtain a precise response time when issuing a command to an EtherCAT slave device.

Localization in a wireless sensor network (WSN) becomes important for many modern applications, like landslide detection, precision agriculture, health care, and so forth. The more precise the position of an anchor node is, the more accurate the localization of a sensor node can be measured. Since the Global Positioning System (GPS) device cannot work properly indoor, some existing localization methods configure anchor nodes in a manual fashion. However, neither applying GPS modules nor manually configuring anchor nodes is suitable for a WSN and especially artificial errors of manual configuration may be propagated and affect the results of localization. In this paper, we propose an alternative method to estimate anchor node locations in an indoor environment. We collect the Received Signal Strength Indicator (RSSI) data from the anchor node when human is walking around them. Meanwhile, we use a wearable IMU-camera device to assist the moving trajectory estimation. We implement a monocular Visual Odometry with a human walking model to estimate moving trajectories. An Unscented Kalman Filter (UKF) is used to estimate the anchor node location by fusing the RSSI data and moving trajectory. The experiment results show that the proposed method has lower estimation error when locating anchors.

Firefox OS, a new Web-based OS developed by Mozilla mainly for mobile platforms, is designed to realize the "Boot to the Web" concept for the open Web. It supports users booting to the network directly, launching remote applications and accessing remote data with the standard Web technologies. Although Firefox OS has adopted several mechanisms to enhance its security, its current design is lack of a mechanism to detect 1) applications calling Web API with unusual frequency, and 2) applications consuming abnormal amount of resources. In this paper, we propose an anomaly detection module which takes the system resource usage and the amount of inter-process communication as the inputs to detect whether the system has an anomaly. We also conduct several experiments to examine the ability of the proposed module. The results show that detection accuracy of our module is 0% in false negative rate and 12.5% in false positive rate.

This paper presents a generic electronic payment model which is intended for a multi-merchant transaction, in which more than one merchant (the retailer, multiple resellers and content providers) are involved in the distribution of electronic contents. With our payment model, every involved merchant will be notified to verify the license information of a content on the settlement day before the customer actually pays for his purchase. Thus, piracy can be discouraged, intellectual property rights of electronic contents can be protected. Each of the involved merchants can obtain his own deserved share of the customer's payment in accordance with their union agreement on this content. As examples to demonstrate the applications of our generic payment model, two well-known payment systems are enhanced herein, based on our payment model.

One proposed method for mitigating the address shortage problem in IPv4 is to use network address translators (NATs) to allow address reuse. The basic idea is to transparently map a wide set of private network addresses and corresponding TCP/UDP ports to a small set of globally unique public network addresses and ports. NAT devices provide a way to handle IP address depletion incrementally, without changing hosts and routers, until more long-term approaches like IPv6 can be implemented. Existing Internet security protocols must be re-examined, however, to see how they function within this new network environment. We begin with a description of the four NAT environments and a discussion of their limitations. We then examine the relationships between NAT devices and popular Internet security protocols and applications at each layer of the TCP/IP stack to see if they can survive with NAT devices.

This paper introduces the role of a PCS in a critical infrastructure, and especially addresses the processing flow and control of a water system. By leveraging advanced IT technologies, a modern process control system (PCS) can help monitor and control physical processes in a water system. Conventionally, a water system is composed of a water treatment subsystem and a water distribution subsystem. To provide better water quality and steady water flow, PCSs should be adopted in these subsystems to more precisely control the concentration of chemicals in water and the outlet valve of water tanks. We investigate the security issues and possible attacks in a water system adopting a close-loop control mechanism. Taking the concentration control of chlorine in water as an example, we formally explain how an integrity attack leads a water system into a harmful state by adding improper amount of chlorine into water. In the future, we will further develop a formal model describing a n-tank water system, evaluate the impact of simultaneous more attacks and discuss the potential impacts. We will also try to design a detection and defence system to resist against known attacks.

With the increasing popularity of cloud computing, hosting services on a remote virtual machine becomes a trend due to its ease of use and cost saving. When migrating services to a cloud, users need to submit a resource plan to ensure service's performance. However, it is difficult to estimate the resources required by a virtual machine for running arbitrary services. To address the problem, we propose an estimation model for a resource plan. The model takes the performance characteristics of a physical machine as input and estimates virtual machine configurations. Using the estimated configurations, a user can obtain a virtual machine having similar performance characteristics to that of the physical machine. In this paper, we derive a model to estimate the CPU capability for creating a virtual machine on Xen. Our experiments show that our model can provide a resource plan for a virtual machine, which has the minimum performance difference compared with a designated physical machine.

Modern virtualization technologies provides an optimal use of underused hardware resources by sharing them among virtual machines hosted on the same physical machine. These technologies hence have been broadly adopted in many areas, such as server consolidation, virtualized network test beds, etc. A large-scale network test bed is considered one of the useful tools for evaluating or verifying advanced networking technologies. To construct a network test bed that matches as much as a real setup, the test bed should meet requirements of isolation, fidelity, repeatability, scalability, containment and extensibility. Among these requirements, scalability can be realized by the modern virtualization technology, whereas vulnerability and security weakness brought along with virtualization can also be harmful to the other requirements of a network test bed, like isolation and fidelity. This paper reviews the modern virtualization technologies, their resource management mechanisms, and the known attacks of these virtualization technologies. Then, we discuss the requirements of existing network test beds and the security impacts when introducing such modern virtualization technologies into a network test bed.

The Authentication Key Agreement Scheme (AKA) of Universal Mobile Telecommunication System (UMTS) provides substantial enhancement to solve the vulnerabilities in GSM and other wireless communication systems. However, we discovered four security weaknesses of UMTS AKA, that is, redirection attack, man-in-the-middle attack, sequence number depletion, and roaming attack. An adversary can launch these attacks to eavesdrop, or cause billing problems. To cope with these problems, a new Secure Authentication Key Agreement Protocol (S-AKA) is proposed in this paper to enhance the security to resist the attacks. To improve the efficiency and redundancy of UMTS AKA, S-AKA reduces both the authentication messages and bandwidth consumption of UMTS AKA. The formal proof of S-AKA is also given to ensure the security strength of S-AKA.

In the paper, a hydrodynamic numerical model for predicting the ROV motion with anti-pitch control is presented. The six degrees of freedom of equations of motions are formulated, which includes the coupled effect due to the current and the umbilical cable. Because of the umbilical cable on the ROV, the two-point boundary value problem with respect to a set of first order ordinary differential equation system arises and a multi-step shooting method is suggested to solve this problem. The anti-pitch technique including the depth keeping, either by PD control or PID control, is proposed to maintain the attitude of ROV in the current to reduce the resistance and other disturbance. The results reveal that both controlled techniques can indeed reduce the pitch motion and keep the desired depth for the ROV even in strong current. The hydrodynamic model developed here can therefore serve as a useful tool to improve the performance of the ROV operated in uniform current.

A team of researchers including computer scientists, electrical and control engineers, architects, industrial designers, human factor engineers, and cognitive scientists in the National Chiao Tung University (NCTU), Taiwan, along with their overseas collaborators launched the project Kannon, a multi-disciplinary effort to develop Adaptive Assistive Technologies that can be deployed incrementally into existing private/public spaces and collaborate opportunistically to offer monitoring, assisting, communicating and rejuvenating services to healthy elders. The team combined the state-of-art information, communication and robotic know-how with the activity oriented method for product design and the modular functional approach in modern architecture in order to devise a holistic support for successful aging. This paper presents the philosophy, approach and first fruits of this project.

The paper presents a control flow obfuscation method to discourage reverse engineering and malicious tampering of software codes. Given the original source codes and desired obfuscation criteria, the proposed method works by decomposing the source codes into fragments and then applying various transforms to the code fragments. As the output of our method, the transformed fragments are re-assembled and obfuscated with the designated obfuscation criteria. Moreover, since only control flows are obfuscated with a sequence of transformations that produce equivalent results of the original fragments, the final output can still preserve the same execution results as the original codes. The proposed method can be combined with other security technologies like watermarking or fingerprinting and thus help discouraging software piracy by making watermarked information embedded in software codes difficult to be reverse engineered or tampered.

Typhoid fever complicated by multiple organ involvement has been rarely mentioned in the literature. We reported two cases of typhoid fever with several unusual manifestations, including acute renal failure, acute hepatitis, acute pancreatitis, disseminated intravascular coagulation, and lower gastrointestinal bleeding. A renal biopsy in the first case showed no pathological change. Bone marrow biopsy showed focal necrosis of matrix, which might have been due to severe illness. A liver biopsy in the second case showed a predominantly histiocytic proliferation with occasional neutrophilic infiltration in the portal areas and hepatic sinusoids. Focal necrosis, bile duct injury, and multiple eosinophilic bodies were also noted. After appropriate antimicrobial therapy, both patients recovered without any sequelae. The potential of multiple organ involvement is highlighted in typhoid fever, which, on rare occasions, may occur simultaneously in the same patient.

Purpose: To determine the changes in the expression of transcripts of matrix metalloproteinases (MMPs) and their tissue inhibitor (TIMP) in the conjunctiva following glaucoma filtration surgery (GFS). Methods: The reverse transcription-polymerase chain reaction method was performed on tissue specimens obtained from adult rabbits undergoing GFS at various postoperative time points. Results: MMP 1 decreased more than 7-fold from its baseline level during the first 2 weeks following surgery. MMP 2 decreased on the 1st postoperative day, but increased on day 2, and remained elevated for 2 weeks. The postoperative level of MMP 14 did not change much from baseline except that noted on day 9. The TIMP 1 expression showed an early biphasic pattern. MMP 3 and MMP 9 were not detected in all the specimens. Conclusions: The transcript expression of MMPs and TIMP 1 in the conjunctiva is altered following GFS, with each gene product demonstrating a unique temporal pattern.

The paper presents three key distribution schemes for channel protection. With the proposed schemes, encryption keys of the ordered programs can be distributed to the authorized subscribers efficiently and securely. In these schemes, for key updates, at most two messages are transmitted and simpler computation functions, including one-way hash function and XOR operation, are used to reduce the computation cost compared to existing solutions. With our key distribution schemes, only the authorized subscribers can decrypt the ordered programs. Thus, the service provider in a Pay-TV system can charge his subscribers according to their subscriptions and the intelligent property rights of TV programs can be protected by the proposed schemes.

Objective Nitric oxide synthase is the key enzyme of the conversion of L-arginine to L-citrulline and nitric oxide. We conducted a study to investigate the association between positive inducible nitric oxide synthase (iNOS) mRNA expression and recurrence of bladder cancer. Materials and Methods Seventy-one patients with primary non-muscleinvasive bladder cancer were enrolled in this study. Tumor tissues were harvested during transurethral resection of bladder tumors. All operations were performed at the same hospital. Recurrence-free patients were followed up for at least 1 year unless tumors recurred during that time. The median intervals of follow-up were 34 months in the recurrence-free group and 12 months in the recurrence group. iNOS mRNA was detected using the RT-PCR-based method. Results Bladder cancer patients with positive iNOS mRNA expression had a higher recurrence risk (18.7% vs. 2.6%; p = 0.04). After adjusting for other risk factors, a statistical significance remained ( p = 0.04; hazards ratio = 13.27; 95% CI = 1.07–164.36). The patients also had reduced recurrence-free survival ( p = 0.019). Conclusion The positive expression of iNOS mRNA may be a useful prognostic indicator of bladder cancer.