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In this study, to improve the logistics flow of existing given chemical logistics warehouse, four logistics flow alternatives were proposed to minimize truck interference by building simulation model. The simulation model for chemical storage warehouse was built to evaluate system performance. Among the four new improved alternatives based on the basic model, the model with the same truck’s pathways and locations of facilities identified an increase in the number of interferences but a decrease in daily working hours as the number of resources in a particular facility increases. Therefore, the three groups were classified as ‘efficiency’, ‘complementary’, and ‘safety’ based on the daily working hours, and the ratio of trucks entering two types of logistics warehouse was set in consideration of future market fluctuations. For each of the six types, the optimal number of resources was selected as the number of resources in the facilities with the least number of interferences in the basic model and the evaluation measures and characteristics set in this study were compared and analyzed. As a result, the Alternative 4 model operating the underground roadway produced interference between 17.0% and 36.4% of the basic model, with 113.3% of the interior loadspace.

In this paper, the RF characteristics of multi-finger MOSFETs were improved by decreasing the parasitic capacitance in spite of increased gate resistance in a 90-nm CMOS technology. Two types of device structures were designed to compare the parasitic capacitance in the gate-to-source (C gs ) and gate-to-drain (C gd ) configurations. The radio frequency (RF) performance of multi-finger MOSFETs, such as cut-off frequency (f T ) and maximum-oscillation frequency (f max ) improved by approximately 10% by reducing the parasitic capacitance about 8.2% while maintaining the DC performance.

Corporations should make efforts to recognize the importance of projects, identify their failure factors, prevent risks in advance, and raise the success rates, because the corporations need to make quick responses to rapid external changes. There are some previous studies on success and failure factors of projects, however, most of them have limitations in terms of objectivity and quantitative analysis based on data gathering through surveys, statistical sampling and analysis. This study analyzes the failure factors of projects based on data mining to find problems with projects in an audit report, which is an objective project evaluation report. To do this, we identified the texts in the paragraph of suggestions about improvement. We made use of the superior classification algorithms in this study, which were NaiveBayes, SMO and J48. They were evaluated in terms of data of Recall and Precision after performing 10-fold-cross validation. In the identified texts, the failure factors of projects were analyzed so that they could be utilized in project implementation.

This research focuses on the method of inventory management to find out the best way in various SCM. There are several comparable methods of inventory management like Min-Max, regular interval, fixed target inventory that have different lead-time and demand for each product. Also, the inventory performances between the case of three- stages and two-stages in SCM are analyzed. 8 scenarios for the simulation are suggested considering order ways and stages. Input data for the simulation is from the result of the previous studies and actual data in the market. The performance measurements are selected as sales revenue, total number of sales, total delivery cost, total inventory shortages, the number of inventory shortage occurrence, the loss for inventory shortages, average inventory, handling cost, net profit. According to the results of the simulation, fixed target inventory management is better than existing inventory management method by net profit and inventory and so on. Also, it was confirmed that the increase in profit is obtained when SCM stages is reduced from three-stages to two-stages in existing SCM. The result of the research provides significant meaning that newly introduced target inventory management system shows good performance and SCM performance can be improved by reducing the stages.

In this study, the effects of traffic flow improvements were compared in terms of real traffic data by using the level of congestion, throughput, and average duration time criteria. A current situation and a situation with smart tolling were considered in order to ensure the reliability of the results. The simulation consisted of six scenarios, the error rates were checked with 30 replications, and the error rates were noted to be lower than 0.5%. The scenarios were categorized by vehicle speeds that could affect subsequent vehicles. The smart tolling model was better than the current model overall. In particular, the results of comparing lifelike scenario 1 and scenario 6 with smart tolling are key. The results showed that the level of congestion and average duration time could be decreased to approximately 50%. With regard to the results, there are significant impacts on improving traffic flow while maintaining five lanes, unlike in the current model.

Aluminium doped lithium lanthanum titanate (A-LLTO) powders with various excess Li 2 O content are synthesized using a simple citrate gel method. The obtained A-LLTO powders show an agglomerated form, composed of nano-sized particles of 20–50 nm. The morphology and conductivity of the A-LLTO ceramics are largely affected by the content of excess Li 2 O. The highest total ionic conductivity of 3.17 × 10 −4 S cm −1 is achieved for the A-LLTO sample containing 20% excess Li 2 O, exhibiting a vacancy content of 6%, and a total activation energy of 0.358 eV. The A-LLTO can act as a membrane to protect lithium metal from oxygen and other contaminants diffused through the oxygen electrode part. The Li–O 2 cell employing the A-LLTO solid electrolyte shows a good cycle life of longer than 100 discharge-charge cycles, under the constant capacity mode of 300 mAh g −1 .

This study suggests the two types DEA models such as DEA CCR model and Super Efficiency model to evaluate the value of a company and to apply them for the investments. 14 kinds of real data of companies such as EV/EBITDA, EPS growth rate, PCR, PER, dividend yield, PBR, stock price/net current asset, debt ratio, current ratio, ROE, operating margin, inventory turnover, accounts receivable turnover, and sales growth ratio were used as input variables of DEA models. 12 year data from December 30, 2000 up to December 30, 2012 were collected, and the data with negative, missing and 0 values were removed reflecting the characteristics of the DEA. In order to verify the effectiveness of the models, we compared the historical variability and rate of return of both models those of the market. Study results are as follows. First, two DEA models are more stable than market in terms of rate of return because the historical variability of both models are less than that of market. Second, Super Efficiency model is more stable than CCR model. Lastly, the cumulative rate of return of Super Efficiency model (434%) is greater than that of the CCR model (420%) and that of the market (269%).

In this study, products in a B2B online shopping mall were classified efficiently using DEA, and an operational process is presented. The results using the data of M company were used to calculate the workload according to the category. The work load of managing the product using the DEA has been distributed evenly. In addition, the classification of A is composed of the highest net income, and it was intended to be managed centrally by the company. Business classifications C and B, which were made of a low severity workload, were reduced. Therefore, efficient operation is possible when applied to an actual business.

In this study, when to invest in real estate abroad, to present a real option in the way of decision-making. Thus, by using the binomial option model of one of the real thing and DCF, we compared the choice of real estate investment in China and South Korea. Research concerns the real estate market of Shanghai and Seoul, Analyzed the data between 2001-2009. Results were calculated NPV investment period (Net Present Value), Seoul appears in 435.44, Shanghai was 398.26. Investment decision by NPV method will select Seoul. However, as a result of calculating the value using the real option, it was found that for Seoul appear in 615.4, Shanghai has been shown to 626.1, and is suitable for investment in Shanghai. Assuming on the basis of this, that it has invested in practice, and compare the results, Seoul is intended for since 2010, real estate prices fell to 2013 currently, damage has occurred, profit's occurred Shanghai. This ensures that when making decisions in real estate investment and to use the real option than the existing DCF is appropriate.

The research focuses on the method to improve the Logistics considering investigating the present state of the fast growing social commerce. The improving Logistics is the jointed transport system, which proposes the concept of the packaged delivery for customers in same area and the condition-specific benefits as the transport cost and delay period. Customers in this system will obtain the advantage as the decrease of transport cost and social commerce companies will make the effect about growing the number of customer and the sales by the lowest price in the online markets. There are 7 scenarios for simulation. The performance assessment of the results from simulation is carried out by total number of orders, finished number of orders, sales, delivery times, delivery cost, earlier rate of delivery, and fluctuation of number of wrong delivery. The results of the research show that the total number of orders, finished number of orders and sales are increased, while the times and cost of delivery are decreased.

The paper addresses the introduction of outsourcing of delivery service for the small service industries such as delivery based restaurant in order to increase the profit and revenue of the service company, upgrade the delivery satisfaction for the customers, and expand the welfare of the senior people through the work. The chinese restaurants are selected as model service companies, outsourcing of delivery services are suggested for those restaurants and simulation models are developed for all operation systems for them. Some of input data for the simulation are collected from the real world and others are refined through the interview with the field workers. 6 scenarios are established considering the number of deliverers and delivery charges and simulation experiments for each scenario have been done according to the 3 kind of situations of the service companies. The results show that introduction of outsourcing increases the revenue and profit of the service company, decreases the service time for the customers and increases the revenue of the delivery outsourcing company employing the senior people. So delivery outsourcing for the service industries can be considered as a good solution for the welfare problem of the senior people.

In this paper, octagonal inductors for RFIC designs was fabricated with 90nm CMOS Technology to compare its quality factor and the effective inductance as functions of radius and number of turn. The quality factor decreases as the inner radius and the number of metal turned increase. However, the effective inductance increases with the increasing the inner radius and the number of metal turned. Therefore, the inductor structure should be decided according to the relative importance of Q-factor and inductance.

This paper suggests Effectiveness Evaluation Methods of DDoS attacks countermeasures model by simulation. According to the security objectives that are suggested by NIST(National Institute of Standards and Technology), It represents a hierarchical Effectiveness Evaluation Model. we calculated the weights of factors that security objectives, security controls, performance indicator through AHP(Analytic Hierarchy Process) analysis. Subsequently, we implemented Arena Simulation Model for the calculation of function points at the performance indicator. The detection and protection algorithm involve methods of critical-level setting, signature and anomaly(statistic) based detection techniques for Network Layer 4, 7 attacks. Proposed Effectiveness Evaluation Model can be diversely used to evaluate effectiveness of countermeasures and techniques for new security threats each organization.

Ptak & Smith published ORLICKY’S Material Requirement Planning Third Edition in 2011 to correspond the rapidly changed market demand by improving the original MRP based on Theory of Constraints(TOC) replenishment inventory management. This study is to develop the simulation model to decide the proper target inventory level for TOC replenishment inventory management using system dynamics Vensim software. This study shows that the proper target replenishment level is how much significant to manage the inventory by the random sample data simulation. This simulation model will be extended to compare the results of the TOC replenishment inventory management planning with the results of the old MRP planning by the enterprise actual inventory data. Key words : TOC, Replenishment, Buffer management, Target inventory level, System Dynamics요 약Ptak과 Smith는 2011년 올리키의 MRP 3판을 통하여 TOC 재보충방식을 기반으로 기존 MRP 방식에 의한 재고관리의 문제점을 오늘날 급변하는 수요중심의 시장 상황에 대응할 수 있도록 발전시킨 수요 대응형 MRP 방법론을 제시하였다. TOC 재보충방식은 목표재고수준을 기준으로 재고 가용성을 유지하여 급격한 변화에 따른 혼란을 흡수하면서 수요량에 연동하여 목표재고수준을 조정하는 수요대응형 MRP의 기본이 되는 재고관리 방식이다 . 본 연구에서는 Vensim 시스템 다이내믹스 시뮬레이터를 활용하여 적정 목표재고 수준을 관리하고자 할 때 적정한 목표재고수준 결정을 위한 기준 공식 및 절차를 예 시하고, 임의 수요를 발생시켜 TOC 재보충방식의 목표재고수준 모형별 운영 결과 비교 검증을 통하여 모델의 효용성을 비교 검토하였다. 향후에는 기존의 MRP에 의한 재고관리 방식과 수요 대응형 MRP에 의한 재고관리 방식 운영결과의 차이를 실제 기업의 데이터를 활용하여 시뮬레이션 할 수 있도록 모델을 확대 적용할 예정이다 .주요어

This paper is about the investment strategy in stocks on Fundamental analysis. Financial data of stocks from January 2. 2001 through October 30. 2009 were utilized in order to suggest the investment strategies. Fundamental analysis was used in stocks-related strategy. The portfolios are composed of 3 criteria such as the buying criteria score, exchange cycle and selling conditions. The buying criteria score is determined assigned to each stock index according to the satisfaction condition of 15 parameters selected considering the grue`s criteria. The stock buying alternatives has two options with buying stocks over 13 points and over 14 points of buying criteria score. The seven exchange cycles and three selling methods are considered. So total number of portfolios is 42($2{\times}7{\times}3

Most of Orders of Magnitude estimate are based on historical data. This data is converted to the current price using by the cost index method mainly. This method, however, is rarely utilized or only for one-time use due to the lack of data and the complex escalation calculation method. This paper present a typical process on the conceptual investment cost estimation using by Cost Indexes based on the actual case for the Train Control facility of High-speed rail project. The result is expected to serve as both an easy way for Order of Magnitude estimate and a standard guideline for computerized modeling.

The objective of this study is to enhance the Ad hoc On-demand Distance Vector (AODV) routing protocol, a representative mobile ad hoc network environment routing protocol. In the existing AODV protocol, dynamic topology changes due to node mobility cause frequent route failures and network instability. We herein propose a local repair scheme to re-establish routes when links are broken and a dual-path routing scheme to improve network stability by employing alternate routes. After comparing the total data processing volumes, average packet end-to-end delays, numbers of connection pairs, energy consumptions, and numbers of generated packets of the enhanced AODV protocols, we discuss the optimal operating conditions for each scheme. We also investigated the performance variations resulting from changing the number of nodes and node mobility, using an NS-2 simulator. The results revealed that the dual-path protocol generally performs the best and improves the packet end-to-end delay by up to 45 %.

This paper presents a newly proposed T-model of spiral inductors in 90nm radio frequency (RF) CMOS technology. Inductor modeling is one of the most difficult problems facing silicon-based RF integrated circuit designers, and the inclusion of many parameters of the inductor equivalent circuit consumes a lot of time during circuit simulation. In this paper, two models of spiral inductors were simulated to compare their agreement with the measured data from 100MHz to 10GHz. The proposed T-model had less parameters than the conventional double-π model, and also showed good agreement in the RF performance of the spiral inductors, such as quality factor (Q-factor) and inductance (L). In addition, the proposed T-model had an error rate of less than 5% with the S-parameter of measured data, similar to the double-π model.

This paper deals with a scheduling problem in a flexible job shop with multi-level job structures where end products are assembled from sub-assemblies or manufactured components. For such shops MRP (Material Requirement Planning) logic is frequently used to synchronize and pace the production activities for the required parts. However, in MRP, the planning of operational-level activities is left to short term scheduling. So, we need a good scheduling algorithm to generate feasible schedules taking into account shop floor characteristics and multi-level job structures used in MRP. In this paper, we present a GA (Genetic Algorithm) solution for this complex scheduling problem based on a new gene to reflect the machine assignment, operation sequences and the levels of the operations relative to final assembly operation. The relative operation level is the control parameter that paces the completion timing of the components belonging to the same branch in the multi-level job hierarchy. We compare the genetic algorithm with several dispatching rules in terms of total tardiness and the genetic algorithm shows outstanding performance for about forty modified standard job-shop problem instances.

This paper proposes supply network with a global bill of material (BOM). Design and planning problems of supply network in a single combined system were modeled and an experiment was performed on an example problem to confirm the viability of the new, proposed system. The new supply network management system consists of four modules: supply network design optimization module, planning module for production and distribution operations from raw material suppliers to customers, model management module and data management module. The first two modules are solved by a Lagrangian heuristic and a genetic algorithm, respectively. The model and data management modules relieve managers from the difficult task of handling the details of data and mathematical models. Experimental results support our view that the design and planning of supply network problems with a global BOM could be optimized if we adopt appropriate strategies and algorithms.

B2O3-added Li(1.5)Al(0.5)Ge(1.5)(PO4)3 (LAGP) glass ceramics showing a room temperature ionic conductivity of 0.67 mS cm(-1) have been synthesized by using a melt-quenching method. The prepared glass ceramics are observed to be stable in tetraethylene glycol dimethyl ether containing lithium bis(trifluoromethane) sulfonamide. The augmented conductivity of the B2O3-added LAGP glass ceramic has improved the plateau potential during discharge. Furthermore, the B2O3-added LAGP glass ceramics are successfully employed as a solid electrolyte in a Li-O2 battery to obtain a stable cycling lifetime of up to 15 cycles with the limited capacity protocol.

In this study, the ‘Value Score Method’ is proposed to evaluate the corporate value portfolio by using values that affect corporate value. Using a simulation analysis, this paper considers the results of six scenarios consisting of various selection criteria (5, 7, 10, 11, 12, 13 point). The performance measurements are the number of selected companies and the ‘rate of return.’ The results indicate that scenario 2 consisting of the 7-point value score displayed the highest rate of return but was identified as having significant difficulty in real world application because many management companies are faced with the problem of specific companies generating this rate of return. Thus, the scenario 3consiting 10 point value is the most realistic scenario and the good rate of return in the model. In addition, scenario 7 was set as the combination of scenario 1 consisting of the 5-point value in the down market and scenario 2 consisting of the 7-point value in the up market. Scenario 7 applied to the intersection of the reference point showed a higher cumulative return of 5,276.2% as compared with scenario 2 with an average of 190.4 companies selected.

This paper discusses planning and scheduling problems for efficient use of an FMS and presents an integrated decision support system for dealing with these problems. The decision support system, FMSDS (Flexible Manufacturing Systems Decision Support System), includes several modules: data handling module, part selection module, loading module, load adjusting module, scheduling module and simulation module. This paper suggests the solution methodology of each subproblem. Also, an integrated interface scheme between the subproblems is presented. The interface scheme considers the relationships between the subproblems and generates solutions using hierarchical and looping approaches. FMSDS is made up of six alternative models considering three loading objectives and two production order processing strategies. Performance comparison among the six alternatives is shown using the non-terminating simulation techniques.

Normally, the Railroad Constructions need the huge budgets due to the large-scale works including civil, tunnel and bridge. Thus, it is so difficult to estimate the budgets out of data in the previous works. This research presents two models; (1) the conceptual estimation model by using the parametric method and regression analysis (2) the range estimation model for estimation of accuracy. Also, the simulation has been used for verifying the validity of the results from the conceptual estimation model to find the expected cost of High-Speed Railroad construction. In addition, the range estimation model for estimation of accuracy is generated by using Monte Carlo Simulation. Crystal Ball Program as a tool of the simulation is used in the research. The performance measures are used Percentage Error and the criterion according to the ACCE [1]. It is expected to improve the accuracy of the model and to contribute to effective total cost management.

In this paper, the machine loading problem (MLP) as an example of combinatorial problems is presented within a Flexible Manufacturing Cell (FMC) environment. In general, MLP can be modeled as a general assignment problem and hence formulated as 0-1 mixed integer programming problem which have been effectively solved by a variety of heuristics methodologies. Recently, Neural Networks have been applied to various problems with a view of optimization. Especially, Hopfield Networks to solve MLP having objective of balancing workload of machines is discussed in this paper. While heuristic methods may take a long time to obtain the solutions when the size of problems is increased, Hopfield Networks are able to find the optimal or near-optimal solutions quickly through massive and parallel computation. By such capabilities of Hopfield Networks, it is also possible to approach real-time optimization problems. The focus in this paper is on the quality of solutions of Hopfield Networks by means of comparison with other heuristic methods through simulation, considering machine-breakdown. The simulation results show that the productivity of parts is highly improved and that utilization of each machines is equalized by achieving a balanced workload on machines.

Customers are demanding shorter lead times and higher product variety without making concessions on product price and quality. To remain competitive, a manufacturing system needs to react adequately to perturbations on its environment and uncertainties in manufacturing processes. The paper touches upon three research topics for the development of a scheduler based on manufacturing system states: development of a simulator for the simulation of a manufacturing system, the clustering method for manufacturing system states, and the search method for the most compatible dispatching rule to a manufacturing system state. Finally, the results of simulation experiments are given to compare the proposed method with other scheduling methods. The result shows that the superiority of the proposed scheduler. In the process of developing the scheduler, a general methodology for the development of a simulator and the clustering method for system states were developed. The proposed methodology for the development of simulators seems to be useful for developing simulators for various domains. The clustering method of system states and the knowledge acquisition method for scheduling rules are shown to be efficient for the development of an autonomous real-time scheduling system.

To date, lithium lanthanum titanate (LLTO) of the nominal formula Li3xLa2/3-x 1/3-2xTiO3 with perovskite structure have been considered to be promising solid electrolyte materials for lithium-oxygen battery due to a numerous outstanding advantages such as: (i) a high lithium conductivity at room temperature, (ii) a high lithium diffusion coefficient, (iii) a low electronic conductivity, and (iv) an electrochemical window larger than 4 V. However, the LLTO materials have also suffered from a few disadvantages such as insufficient total conductivity due to the large grain boundary resistance and difficulty in controlling Li+ content and Li+ conductivity of the materials especially after exposure to high annealing temperature. In addition, when the LLTO contacts directly with Li metal, Ti4+ in LLTO can be reduced into Ti3+ by metallic Li leading to increase in the electron conductivity of LLTO. In this study, we investigated the feasibility of application of Al-doped LLTO ceramics with nominal formula of (Li1/3La5/9)1.005Ti0.99Al0.01O3 (denoted as A-LLTO) in Li–O2 batteries. A-LLTO was synthesized using sol-gel modified Pechini method in the aim of (i) reducing the synthesis temperature (up to 300-400 oC compared to the conventional solid state reaction method); (ii) lessening loss of lithium and gaining homogeneous mixture easily. As referred above, since LLTO cannot contacts directly with Li metal, prior to being assembled in organic- type Li-O2 battery as an electrolyte separator On the A-LLTO ceramics with 16 mm diameter and 200 m thickness, a thin protective layer of LiPON of 200 nm in thickness was sputtered for separation of A-LLTO from the Li metal anode. The perovskite material was used as catalyst for cathode material of the batteries. The XRD patterns of A-LLTO ceramics obtained after annealing were compared and matched with Li0.33La0.56TiO3 (Code: 01-087-0935; Tetragonal) confirming purely the tetragonal crystalline structure P4/mmm space group of perovskite phase without secondary phases. After polished and heat etched at, the surface of the ceramics was observed using SEM. T ceramics was composed of grains of typical rectangle shape connected together closely. The largest grain size reached 100 m. Ionic conductivity of A-LLTO measured using electrochemical impedance spectroscopy (EIS) exhibited the relatively high conductivity of 3.17 10-4 S/cm. This is attributed to the low total activation energy of 0.358 eV and the somewhat large crystal grain size compared with ceramics prepared at the same temperature. The Li-O2 cells employing the A-LLTO ceramic electrolytes were tested in galvanostatic and constant capacity mode. Effect of current density and operating temperature on the charge-discharge behavior of Li-O2 cell was investigated. The Li-O2 cell employing A-LLTO electrolyte layer exhibited the satisfactory performance.

B2O3-added Li1.5Al0.5Ge1.5(PO4)3 (LAGP) glass ceramics showing a room temperature ionic conductivity of 0.67 mS cm−1 have been synthesized by using a melt-quenching method. The prepared glass ceramics are observed to be stable in tetraethylene glycol dimethyl ether containing lithium bis(trifluoromethane) sulfonamide. The augmented conductivity of the B2O3-added LAGP glass ceramic has improved the plateau potential during discharge. Furthermore, the B2O3-added LAGP glass ceramics are successfully employed as a solid electrolyte in a Li–O2 battery to obtain a stable cycling lifetime of up to 15 cycles with the limited capacity protocol.