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This article proposes stochastic exploration algorithms for mobile robot exploration problems. Navigation with uncertain conditions in the absence of initial parameters is a situation wherein precomputation and prediction are impossible for a robot. Therefore, stochastic optimization techniques were applied to find the optimal solution for the robot exploration problem. Driving to the unknown areas, the robot updates the frontier line of sensor visibility during the exploration mission. The points of the frontier line are assumed as the swarm population with their own positions and costs, which allows the computation of the next global waypoint. The calculation of global waypoints is carried out by a nature-inspired optimization algorithm that can place a waypoint in uncertainties. This study offers to apply three metaheuristic algorithms individually, such as Whale Optimization, Grey Wolf Optimizer, and Particle Swarm Optimization algorithms, for comparison and testing their performances in the mobile robotics. At first, the simulations based on the proposed exploration algorithms were implemented and evaluated in a created environment. The results were compared in a single and average cases. Then, the real-world experiments using Grey Wolf Optimizer exploration algorithm were conducted in the different types of environments using MATLAB-ROS integration tool. These results proved the effectiveness and applicability of the bio-inspired optimization algorithm in the mobile robotics.

Environmental crisis challenges human race harder than ever before. Ecologists have produced a massive amount of data to cope with the crisis. Accordingly, so many ecological data platforms have been developed worldwide to manage and analyze these datasets. However, in Korea, ecological datasets produced by different research institutes for different purposes have not been integrated or serviced due to the lack of a well-designed information infrastructure. To address this obstacle, we present EcoBank (www.nie-ecobank.kr), an open, web-based ecological data platform designed to play an important role in ecological informatics in Korea. The architecture of EcoBank comprises core technologies of WebGIS, Application Programming Interface (API), responsive web, and open-source software (OSS). EcoBank has three conceptual modules: data management, analysis, and service. Diverse stakeholders of EcoBank can be classified into three groups: researchers, policymakers, and public users. EcoBank aims to expand its horizons through mutual communication between these stakeholders. As a part of the progress, EcoBank began to broaden its network by linking to other data platforms and repositories over the globe to find possible solutions to ecological issues in Korea.

In the present work, the application of LCD waste glass as a flux material substituting for the traditional feldspar in ceramic tiles was studied. The viscosity of LCD glass at the sintering temperature of the ceramic tile was found to be optimal for the dense solid that is obtained from the sintering of the glass powder. The sintered body containing LCD waste glass showed a dense microstructure due to the rich liquid. Even for full replacement of feldspar, neither pyroplastic deformation nor liquid exudation was observed. Overall, properties such as water absorption and the thermal expansion coefficient were positively affected by LCD waste glass substitution. Moreover, the mullite content in the sintered body was almost unchanged. These results were discussed in terms of the apparent viscosity and glass composition.

The objective of this paper is to propose a heuristic algorithm to optimize the railway track maintenance scheduling, a NP-hard problem, by reflecting conditions of the actual field more quickly and easily. We develop the mechanism based on Binary Artificial Bee Colony (BABC) and Binary Harmony Search (BHS), and verify their performance through simulation experiments. Our proposed BABC and BHS mechanisms were applied to problems composed of 30, 60, 100, and 200 operations for railway track maintenance scheduling to carry out experiments and analysis. On comparing it with the results solved by CPLEX, it is found that the mechanism could present an optimal solution within limited time by user.

The redox reaction M (x+n) + n/2O ?2 + M x+ + n/4O₂ of multivalent ions in glass melts influences the melting process and final properties of the glass including the fining (removal of bubbles), infrared absorption and homogenization of melts, reaction between metal electrodes and melts or refractory and melts, and transmission and color of glass. In this review paper, the redox behaviors that occur frequently in the glass production process are introduced and the square wave voltammetry (SWV) is described in detail as an in situ method of examining the redox behavior of multivalent ions in the melt state. Finally, some voltammetry results for LCD glass melts are reviewed from the practical viewpoint of SWV.

The core of the CNG fueling station is the compressor and most of CNG compressors in Korea require lubrication. Lubrication oil of CNG compressor that can be transferred into the pressure regulators and the engines of fueling system can cause a negative effect on NGV(Nature Gas Vehicle) performance during refueling due to oil Carry-over. In order to avoid the problem, it is necessary to enhance the quality of the compressed natural gas by measuring quantitatively the amount of the transferred oil. In this research, a sampling device and sampling tube were developed, which can be used with a gravimetric method of detection to measure CNG oil Carry-over. In addition, CNG samples were taken at 6 pre-selected CNG fueling stations and analysed for their trace oil Carry-over. The measured total oil Carry-over ranged from 2.569 to 6.509 ppm. This test measurements were compared with those of previous studies to verify the results.

Korea Productivity CenterThis is a report on the history and current status of production planning and control activities in South Korea with regard to Industrial Engineers’ (IEs’) role. One of the main characteristics of Korean global companies is that they make good use of IEs not only in their production but also in higher strategic fields like supply chain management. In these companies it is well demonstrated that instead of adding small part of IE skills to traditional engineers, it is much more competitive to have IEs work with them as a team since IEs are fully proficient in every kind of productivity and quality improvement tools. It is also observed that IEs become more productive when they have good domain knowledge in their own industries like semi-conductor, automobile, telecommunications, steel, shipbuilding, etc. So teaching the basics for manufacturing processes to IE students seems very important for their future career development.

Biogas production and utilization are an emerging alternative energy technology. Biogas is produced from the biological breakdown of organic matter through anaerobic digestion. Biogas can be utilized for various energy sectors such as space heating, electricity generation and vehicle fuel. Especially, to be utilized as vehicle fuel, raw biogas needs to be upgraded that is mainly the removal of carbon dioxide to increase the methane content up to more than 95 ~ 97 vol% in some cases, similar to the composition of fossil-based natural gas. Usage of Biogas as a fuel of vehicles have an effect of reducing emission compared to fossil fuels. Biomethane which is produced by upgrading of biogas is regarded as a good alternative energy and usage of clean energy is encouraged to deal with air pollution and waste management as well as production of clean energy. Recently, biogas projects for vehicle fuel are newly being launched and Korea government have also announced a plan for investment to develop biogas as a transport fuel. In this study, it is aimed to examine the potential feasibility of biomethane as a transport fuel. As a results, the status of biomethane, quality standard, quality characteristics, and upgrading technology of biogas were investigated to evaluate of biogas as a vehicle fuel of transportation.

The objective of this study was to compare greenhouse gas emissions from road transportation by calculation methods (Tier 1, Teir 2, and Tier 3). Tier 1 based on 2006 IPCC guidelines default emission factor and amount of fuel consumption. The Tier 2 approach is the same as Tier 1 except that country-specific carbon contents of the fuel sold in road transport are used. Tier 2 based on emission factor of guidelines for local government greenhouse gas inventories (Korea Environment Corporation), the fuel consumption per one vehicle, and the registered motor vehicles. The Tier 3 approach requires detailed, country-specific data to generate activity-based emission factors for vehicle subcategories (National Institute of Environmental Research) and may involve national models. Tier 3 calculates emissions by multiplying emission factors by vehicle activity levels (e.g., VKT) for each vehicle subcategory and possible road type. VKT was estimated by using GIS road map and traffic volume of the section. The GHG average emission rate by the Tier 1 was 728,857 /yr, while Tier 2 and Tier 3 were 864,757 /yr and 661,710 /yr, respectively. Tier 3 was underestimated by 10.1 and 20.7 percent for the GHG emission observed by Tier 1 and Tier 2, respectively. Based on this study, we conclude that Tier 2 is reasonable GHG emissions than Tier 1 or Tier 3. But, further study is still needed to accurate GHG emission from Tier 3 method by expanding the traffic survey area and developing the model of local road traffic.

Coal mine subsidence hazard can be effectively evaluated by geographic information system GIS analysis if sufficient data is provided. It is, however, difficult to obtain ground-based data, especially in remote and less populated mining areas. In this study, we construct and validate a coal mine subsidence hazard map in Taebaek, Korea, by integration of space-borne L-band synthetic aperture radar SAR measurements and a fuzzy-based subsidence model. There is an approximately 15-year time interval between the radar measurements used for the subsidence hazard model and those used to validate the subsidence. A subsidence hazard map was constructed using Japanese Earth Resources Satellite JERS-1 SAR data from the early 1990s and the subsidence model. For the coal mine subsidence hazard mapping, a certainty factor analysis was used to estimate the relative weights of four control factors influencing coal mine subsidence, and the relative weight of each factor was then integrated to produce a subsidence hazard index by a fuzzy combination operator. The predicted hazard areas were then investigated and validated by comparison with subsidence occurrences observed by Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar ALOS PALSAR interferometry in 2007–2008. The results showed a good agreement between the predicted locations vulnerable to subsidence and the actual subsidence occurrences with a prediction accuracy of about 73% and a root mean square error of about 0.35. These results demonstrate that a map produced by integration of a subsidence model and SAR interferometry can be used to predict and monitor coal mine subsidence hazards, especially in remote regions.

Quantitative determination of locations vulnerable to ground subsidence at mining regions is necessary for effective prevention. In this paper, a method of constructing subsidence susceptibility maps based on fuzzy relations is proposed and tested at an abandoned underground coal mine in Korea. An advantage of fuzzy combination operators over other methods is that the operation is mathematically and logically easy to understand and its implementation to GIS software is simple and straightforward. A certainty factor analysis was used for estimating the relative weight of eight major factors influencing ground subsidence. The relative weight of each factor was then converted into a fuzzy membership value and integrated as a subsidence hazard index using fuzzy combination operators, which produced coal mine subsidence susceptibility maps. The susceptibility maps were compared with the reported ground subsidence areas, and the results showed high accuracy between our prediction and the actual subsidence. Based on the root mean square error and accuracy in terms of success rates, fuzzy γ-operator with a low γ value and fuzzy algebraic product operator, specifically, are useful for ground subsidence prediction. Comparing the results of a fuzzy γ-operator and a conventional logistic regression model, the performance of the fuzzy approach is comparative to that of a logistic regression model with improved computational. A field survey done in the area supported the method’s reliability. A combination of certainty factor analysis and fuzzy relations with a GIS is an effective method to determine locations vulnerable to coal mine subsidence.

This study presents the application of interferometric synthetic aperture radar (InSAR), small baseline subset (SBAS) algorithm and GIS for subsidence analysis in a mining area located at Gangwon-do, Korea. Several mining areas at the Samchuk coalfield had operating coalmines until 2002–2003. Ground deformation has occurred as a form of subsidence due to the continuous mining activity or the collapse of residual cavities. Twenty-three scenes from a JERS-1 satellite acquired from 1992 to 1998 are used to detect the ground movement by means of the differential InSAR process. Distinctive phase variations induced by subsidence were observed in several interferograms. The SBAS algorithm was applied for a detailed analysis. As a result, it was confirmed that deformation was occurring between September 21, 1992 and September 30, 1998 and attained 22 cm at the most significantly subsiding site. The mean and standard deviation of RMS error were 2.0 cm and 0.78 cm, respectively, showing the level of the error due to the used digital elevation model, unwrapping and atmospheric effect. The SBAS-derived cumulative subsidence map was validated with the underground workings and geological maps in order to find the spatial relations and subsiding mechanism. From the spatial comparison with these data, it was shown that the subsidence has taken place above excavations and fault lines.

This study constructs a hazard map for ground subsidence around abandoned underground coal mines (AUCMs) at Samcheok City in Korea using a probability (frequency ratio) model, a statistical (logistic regression) model, and a Geographic Information System (GIS). To evaluate the factors related to ground subsidence, an image database was constructed from a topographical map, geological map, mining tunnel map, Global Positioning System (GPS) data, land use map, lineaments, digital elevation model (DEM) data, and borehole data. An attribute database was also constructed from field investigations and reports on the existing ground subsidence areas at the study site. Nine major factors causing ground subsidence were extracted from the probability analysis of the existing ground subsidence area: (1) depth of drift; (2) DEM and slope gradient; (3) groundwater level, permeability, and rock mass rating (RMR); (4) lineaments and geology; and (5) land use. The frequency ratio and logistic regression models were applied to determine each factor’s rating, and the ratings were overlain for ground subsidence hazard mapping. The ground subsidence hazard map was then verified and compared with existing subsidence areas. The verification results showed that the logistic regression model (accuracy of 95.01%) is better in prediction than the frequency ratio model (accuracy of 93.29%). The verification results showed sufficient agreement between the hazard map and the existing data on ground subsidence area. Analysis of ground subsidence with the frequency ratio and logistic regression models suggests that quantitative analysis of ground subsidence near AUCMs is possible.

For substrate glass applied to PDP (Plasma Display Panel), it has been developed many glass compositions that have to not only meet the specifications of PDP but also satisfy the float process as production technology. In the present work, several compositions with no deformation at PDP processing temperature and thermal expansion coefficient of 83~90 × 10 -7 /K were designed. Based on viscosity at high temperature and liquidus temperature for those compositions, three candidate compositions named T-2, T-4, T-6 were selected finally. It was examined additionally that thermal shrinkage at PDP processing temperature and visible transmittance. The properties of T-series were compared with those of commercial glasses and discussed from the view point of PDP device and glass production.

Viscous-driven pumping is a very promising type in microscale applications. However, there exist a few disadvantages such as low efficiency and small volume flow rate. In the present study, a pump with tandem rotating cylinders and its optimum synthesis are proposed fur enhancing pumping performance. First, using an unstructured grid CFD method, we investigate the effects of geometrical parameters and then the performance of the pump with tandem cylinders is evaluated. Next, an optimum design synthesis tool is constructed by combining the aforementioned CFD analysis model with the mathematical optimization model, namely, Modified Method of Feasible Directions (MMFD). This technique is used to optimize the geometrical parameters of the pump, fur maximizing pumping efficiency. From the optimization results, it is believed that the present optimum synthesis is robust and has a potential fur other microfluidic device design.

Novel silicon-based copolymers show the UV-visible strong absorption bands around 347∼387 nm. Their maximum photoluminescence (PL) wavelengths for silicon-based copolymers appeared around 420∼480 nm in the blue region. The present copolymers with a relatively short π-conjugation length exhibit blue light-emitting diodes (LED) at the low operating voltages, due to the reduction of the LUMO level in luminescent polymers by introducing silicon atoms in luminescent polymers as well as the d-orbital participation of silicon atoms.

Objectives This study aims to investigate the suitability of electronic health record (EHR) systems in Korea for global certification and to propose functions for future global systems by comparing and analyzing the certification criteria for Certification Commission for Health Information Technology (CCHIT) Certified Ambulatory EHR with BESTCare, which is the EHR system at Seoul National University Bundang hospital. Methods Domain expert groups were formed to analyze the inclusion of BESTCare functions and the types of differences for each of the CCHIT Certified 2011 Ambulatory EHR Certification Criteria. The types of differences were divided into differences in functions (F), differences in business processes (B), and differences in government policies (P). Results Generally, the criteria that showed differences in functions pertained to the connection between the diagnosis/problem list and order, the alert and warning functions for medication-diagnosis interactions, and the reminder/instruction/notification messages related to the patient's immunization status; these absent functions were enhanced clinical decision support system (CDSS) functions related to patient safety and healthcare quality. Differences in government policies were found in the pharmacy's electronic prescription functions, while differences in business processes were found in the functions constrained by the local workflow or internal policy, which require some customization. Conclusions Functions that differed between the CCHIT certification criteria and the BESTCare system in this study should be considered when developing a global EHR system. Such a system will need to be easily customizable to adapt to various government policies and local business processes. These functions should be considered when developing a global EHR system certified by CCHIT in the future.

This paper applied an adaptive neuro-fuzzy inference system (ANFIS) based on a geographic information system (GIS) environment using landslide-related factors and location for landslide susceptibility mapping. Landslide-related factors such as slope, soil texture, wood type, lithology and density of lineament were extracted from topographic, soil, forest and lineament maps. Landslide locations were identified from interpretation of aerial photographs and field surveys. Landslide-susceptible areas were analyzed by the ANFIS method and mapped using occurrence factors. In particular, we applied various membership functions (MFs), and analysis results were verified by using the landslide location data. The predictive maps using triangular, trapezoidal, and polynomial MFs were the best individual MFs for modeling landslide susceptibility maps (84.96% accuracy), proving that ANFIS could be very effective in modeling landslide susceptibility mapping.

Ground subsidence susceptibility at a coal mine by integration of L-band SAR measurements and a subsidence hazard model incorporated in GIS was estimated. A subsidence hazard map was constructed using JERS-1 SAR data from the early 1990s and the subsidence hazard model. A certainty factor analysis was employed for estimating the relative weights of four control factors influencing coal mine subsidence. The relative weight of each factor was then integrated to generate a subsidence hazard index (SHI) by a fuzzy combination operator. The hazard map was validated by comparison with subsidence observed by ALOS PALSAR interferometry in 2007–2008. The results showed a good agreement between the predicted locations vulnerable to subsidence and the actual subsidence occurrences with an accuracy of about 72.5%. These results showed that the map produced by integration of InSAR and GIS can be used to predict and monitor coal mine subsidence hazards, especially in remote regions.

Biotechnology is the generic technology in the 21st century. It has a strategic importance for the development of companies, industries and nations in the near future. Therefore, many countries have been making a great effort to promote and develop biotechnology. U.S. has been the leading country in the world in promoting biotechnology. However, U.S. biotechnology policy are very diverse, so that there have been no comprehensive and systematic studies on it. In our paper, therefore, we will discuss the U.S. biotechnology policy in detail. For the effective analysis, we will rely on the concept of national innovation system, which emphasize the institutional settings of innovation actors and their interaction. This paper deals with U.S. national innovation system for biotechnology. We will analyze the role of major actors, academia, public research institutes, and industry and their interaction. According to our study, the U.S. biotechnological innovation system is composed of diverse actors and there are lots of start-up companies in biotechnology industry. In addition, there are many diverse policy programs for promoting biotechnology. In the analysis of U.S. biotechnological system and policy, we would like to maintain the Korean perspectives. Because of country-specific frame conditions, Korea and USA have different institutional settings and policies for promoting biotechnology. Therefore, our paper will render meaningful implications for Korea and USA. We also think that this paper will be of interest for international readers.

This study shows the construction of a hazard map for presumptive ground subsidence around abandoned underground coal mines (AUCMs) at Samcheok City in Korea using an artificial neural network, with a geographic information system (GIS). To evaluate the factors governing ground subsidence, an image database was constructed from a topographical map, geological map, mining tunnel map, global positioning system (GPS) data, land use map, digital elevation model (DEM) data, and borehole data. An attribute database was also constructed by employing field investigations and reinforcement working reports for the existing ground subsidence areas at the study site. Seven major factors controlling ground subsidence were determined from the probability analysis of the existing ground subsidence area. Depth of drift from the mining tunnel map, DEM and slope gradient obtained from the topographical map, groundwater level and permeability from borehole data, geology and land use. These factors were employed by with artificial neural networks to analyze ground subsidence hazard. Each factor’s weight was determined by the back-propagation training method. Then the ground subsidence hazard indices were calculated using the trained back-propagation weights, and the ground subsidence hazard map was created by GIS. Ground subsidence locations were used to verify results of the ground subsidence hazard map and the verification results showed 96.06% accuracy. The verification results exhibited sufficient agreement between the presumptive hazard map and the existing data on ground subsidence area.

Objective: The objective was to examine the association of postoperative physical activity with length of stay in patients who received total laparoscopic hysterectomy for benign gynecologic disease. Methods; The case group was composed of 70 patients who entered a critical pathway for elective total laparoscopic hysterectomy from 2009 to 2012 and were discharged behind schedule. The control group was selected from patients who were discharged on schedule, and matched to cases using 1:3 ratio propensity score matching. We compared the number of nursing-documented ambulation of the case group with that of control group. Results; Year of surgery, age, body mass index, endometriosis, systemic disease, previous abdominal surgery and current medication were well balanced between case and control groups. The number of patients with nursing-documented ambulation in case group (19%) was not different from that in control group (11%). Conclusion; Postoperative physical activity measured by nursing-documented ambulation was not associated with length of stay in patients who underwent an elective total laparoscopic hysterectomy for benign gynecologic diseases.

The aim of this study is to define a correlation between spatial distribution of functional feeding groups of aquatic insects and their habitat types in the Geum River based on the theory of River Continuum Concept (RCC). For that object we had classified habitat types of the study area according to various environmental factors and examined closely their distribution characteristics by correlation analysis between biota community and the environmental factors. And then, a probabilistic method named Frequency Ratio Model (FRM) and spatial analysis function of GIS were applied to produce a predictive distribution map of biota community considering their distribution characteristics according to the environmental factors as related variables. As a result, 6 major environmental factors that might affect the classification of habitat types were extracted. Finally, we had compared the predicted distribution map with prior survey database from other researches and then could find out a high correlation between them. The results of this study might be used to develop a new estimation method for aquatic ecosystem with functional feeding groups of aquatic insects and also be used as preliminary data for conservation and restoration of stream habitats.

Novel silicon-based copolymers exhibit the ground-state absorption band maxima around 340390 nm and their photoluminescence in blue region. The blue light-emitting diodes (LED) fabricated with the copolymers could be successfully operated at the considerable low voltages compared to those for other blocked PPV copolymers. The introduction of both silicon and carbazole moieties into PPV main chain results in an interesting dependencies of EL spectral feature on the operating voltage for LED. In order to know the origin of the dependence, we have investigated PL and its excitation spectra of the silicon based copolymeric systems.