• KIPS Transactions on Software and Data Engineering
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• v.9 no.11
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• pp.357-366
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• 2020

As the proportion and complexity of software embedded in aircraft increase, risk factors such as mission failure, function failure and performance failure due to software errors also increase. In the mission-critical software systems such as aircraft software, managing requirement traceability is essential to maintain the software systems with minimal period and cost. However, the development company is not accurately complying with the guideline for managing requirement traceability due to various reasons such as development cost and schedule. Therefore, it is not easy to systematically establish and maintain requirement traceability. In the paper, we analyze actual test cases of aviation software systems from the viewpoint of requirements traceability in order to learn if there are failure cases of test cases due to the absence of systematic traceability management activities. We also check the risks associated with the failure cases according to the type and severity of the cases. As a result of analyzing a total of 7 aircraft-mounted software, failure cases could be divided into three types: omission of requirements, lack of connection between requirements and test procedures, and omission of test procedures. There were a total of 18 failure cases, 6 for each type. The numbers of high, middle and low risks were 1, 13 and 4, respectively, where the number of middle risks is largest.

• Journal of Korean Society of Transportation
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• v.33 no.6
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• pp.564-574
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• 2015

As shown by the popularity of the rapid train in the Seoul Metro Line No. 9, the demand for the rapidization of the metro transit has been continuously increased. However, it needs tremendous cost to construct new additional infrastructures to the existing line for the rapidization. In order to overcome the problem, utilizing the existing infrastructures such as crossing tracks as railroad sidetracks can be considered to be a good method of reducing the cost. In this case, there is a way exploiting the existing train as an express train and the advanced train, which increases both acceleration and deceleration, as a local train, but achievable acceleration and deceleration have not been analyzed rigorously. In this paper, we analyze feasible ranges and optimal values of both acceleration and deceleration of the advanced train analytically when we consider the rapidization of the metro transit utilizing the existing infrastructures and verify the results in Seoul Metro Line No. 3. Simulation results show ranges and optimal values of achievable acceleration and deceleration exist when minimum gap between an express train and a local train is smaller than 40 seconds.

• Journal of the Society of Disaster Information
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• v.11 no.4
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• pp.520-526
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• 2015

Reinforcing bar splices are inevitable in reinforced concrete structure. In these days, there are three main types of splices used in reinforced concrete construction site - lapped splice, mechanical splice and welded splice. Low cost, practicality in construction site, less time consuming and high performance make gas pressure welding become a favorable splice method. However, reinforcing bar splice experiences thermal loading history during the welding procedure. This may lead to the presence of residual stress in the vicinity of the splice which affects the fatigue life of the reinforcing bar. Therefore, residual stress analysis and tensile test of the gas pressure welded splice are carried out in order to verify the load bearing capacity of the gas pressure welded splice. The reinforcing bar used in this work is SD400, which is manufactured in accordance with KS D 3504. The results show that the residual stresses in welded splice is relatively small, thus not affecting the performance of the reinforcing bar. Moreover, the strength of the gas pressure welded splice is high enough for the development of yielding in the bar. As such, the reinforcing bar with gas pressure welded splice has enough capacity to behave as continuous bar.

• Journal of Animal Science and Technology
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• v.52 no.2
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• pp.83-90
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• 2010

Hanwoo proven bulls have been selected since 1987 and consequently contributed to farmers for the improvement of beef cattle in Korea. The demand for the quality beef production as well as higher production efficiency was erupted after early 2000 as relatively cheap imported beef released. Therefore the pressure on the reformation of selection index for Hanwoo proven bulls have been piled up to furnish with Hanwoo's competitive. A total of 734 progeny test data were analyzed to select traits and their weights in the selection index to meet the beef market requirement. Regression analysis with stepwise selection method was used to select proper trait and its weight for selection index. A series of computer simulation was carried out to compare the currently using selection index with the alternate two selection indices proposed in this study. New selection index using standardized breeding values of Loin eye Muscle Area (LMA), Backfat Thickness (BFT) and Marbling Score (MS) with weight ratio 1:-1:6 was proposed. Results showed higher performance in improving MS and BFT gain by 22% and 31% still holding 86%~89% of genetic gain achieved by current index in Carcass Weight (CW) and LMA when new selection index was fitted. Because, new index has little consideration for production cost, further research should be performed to build selection index including cost and income simultaneously.

• Korean Journal of Construction Engineering and Management
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• v.15 no.5
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• pp.61-70
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• 2014

Various procurement systems for Architecture-Engineering service for public construction project are currently established by construction-related law. However, comprehensive framework and criteria for the selection of Architecture-Engineering firm are in absence. Even though various selection methods for Architecture-Engineering service are currently established by law, cost-based selection method is mainly used in selecting Architecture-Engineering firm for the service. This paper examined current use of procurement system for Architecture-Engineering service and drew problems in practice. Through analysis of problems and bench-marking of those systems in advanced countries and international organizations, several strategies to improve performance of Architecture-Engineering service and to maximize the efficiency were suggested. The suggestions include framework and guideline to select a procurement method for the service which is being considered for the project and way of improving current procurement system. These suggestions will be a foundation for utilizing appropriate procurement system for the specific project and can make domestic Architecture-Engineering firm more competitive in the global market by breaking form the cost-based selection method in the selection of Architecture-Engineering firms.

• Korean journal of food and cookery science
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• v.29 no.4
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• pp.343-351
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• 2013

To help reduce the 'breakfast-skip' rate of the high school students and improve such 'breakfast-skipping' practice this study devised a new covenience menu for school breakfast Program. Dictated by a dietitian the form of cooking was rendered within directly-cookable convenient food; The price of menu ranged from 1,500-2,000won taking into account the parents' survey ; the menu formation drew largely from the student food preference survey and their favorites. The composition of menu - the Korean dish and the western dish put together-were of two folds and was based on the two: main menu, subsidiary menu. While main menu used rice, the subsidiary one used fruits, salads, milk, and juices. Energy intake sufficiency standard was set at a level of between 1/4 and 1/3 of the relevent group(mid&high students, 15-18 yrs old)'s approximated energy need, drawn from the Dietary Reference Intakes For Koreans(2010). 10 disparate, divised menus were tested deliberately- cooked at a site, thereafter qualifed and supplemented to meet the targeted energy amount. The nuturitional facts of each menu set were measured through the usage of CAN-PRO 3.0, Computer Aided Nutritional Analysis Program, for professionals. Completed menu set were then given in photograph. The results of this study were as follows : The results of this study were as follows : the newly developed menu's calories and nuturitional content were as follows in the ratio of Dietary Reference Intakes For Koreans(2010) : Calories 95.7%(4.3% below the targeted intake standard), Protein(131.1%), Calcium(130.2%) the both of which marked higher than the recommended daily intake, iron(71.0%), Potassium(93.1%) both of which figure lower than the recommended daily intake. The cost of ingredients per each person was 1,335won, which was lower than the targeted cost(1500won). When calculated, hypothetically provided breakfast's labor hour needed per 1 meal is shown to be average 1.2 minute. In conslusion : Convenience style school breakfast program would bring an increse in the intake of high school students' breakfast, which may contribute not only to the sound physical growth but to academic performance. Various developments of the school breakfast program is much needed continually.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.6
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• pp.120-125
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• 2004

There are very few numbers of 115K FPP (Fixed Pitch Propulsion) Tankers for the Baltic ice class IA because the minimum power requirement of FMA (Finish- Swedish Maritime Association) needs quite large engine power and the 40 m Beam is out of calculation range of FMA minimum power requirements. The shipyard has no choice except to increase the engine power to satisfy FMA minimum power requirement Rule. And the operation cost, efficiency of hullform and its building cost are not good from the ship owners' point of view To solve this problem, the experience of ice breaking tanker development and the ice tank test results were adopted. The main idea to reduce the ice resistance is by reducing waterline angle at design load waterline. The reason behind the main idea is to reduce the ice-clearing force. Two hull forms were developed to satisfy Baltic Ice class IA. Two ice tank tests and one towing tank test was performed at MARC (Kvaener-Masa Arctic Research Center) and SSMB (Samsung Ship Model Basin) facilities, respectively. The purpose of these tests was to verify the performance in ice and open water respectively The hull form 2 shows less speed loss compared to Hull form 1 in open water operation but hull form 2 shows very good ice clearing ability. finally the Hull Form 2 satisfying Baltic ice class IA. The merit of this hull form is to use the same engine capacity and no major design changes in hull form and other related designs But the hull structure has to be changed according to the ice class grade. The difference in two hull form development methods, ice model test methods and analysis methods of ice model test will be described in this paper.

• The KIPS Transactions:PartA
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• v.15A no.6
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• pp.309-316
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• 2008

The mission-critical engagement control computer for air defense has to maintain its operation without any fault for a long mission time. The mission performed by large-scale and complex embedded software is extremely critical in terms of dependability and safety of computer system, and it is very important that engagement control computer has high reliability. The engagement control computer was implemented using four processors. The distributed computer composed of four processors quarantees the dependability and safety, and ASR fault-tolerant technique applied to each processor guarantees the reliability. In this paper, the mechanism and performance of ASR fault-tolerant technique are analysed. And MTBF, reliability, availability, and cost-effectiveness for ASR, DMR and TMR techniques applied to the engagement control computer are analysed. The mission-critical engagement control computer using software-based ASR fault-tolerant technique provides high reliability and fast recovery time at a low cost. The mission reliability of the engagement control computer using ASR technique in 4 processors board is almost same the reliability of the computer using TMR technique in 6 processors board. ASR technique is most suitable to the mission-critical engagement control computer.

• Journal of Korea Port Economic Association
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• v.37 no.3
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• pp.35-53
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• 2021

Over the past 20 years, Korea's number of international passengers and freight transportation records has increased by 8.6% per year, respectively. However, despite the development of sea lanes and increased voyages, there have been constant calls for improving the inefficient management of international passenger ports. Hence, this paper presents improvements and further directions for international passenger port management. Focusing on the Incheon International passenger port as a representative case study, the main results show that the most important, urgent, possible measures for improving the port management include (i) the expansion of customs personnel and implementation of a 24-hours customs clearance system in operation, (ii) installation of buffer facilities between the ferry and ferry cargo and establishment of hinterland specialized in car ferry freight in a facility, and (iii) clear standards for cost-bearing subjects and limitation of high cost related to terminal use in institution. These results imply the need for government policy access and investment reflecting stakeholder opinions at various levels, such as operation, facilities, institution, and so forth, for efficient management of international passenger ports.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.10
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• pp.261-268
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• 2021

Cloud computing is a computing paradigm in which users can utilize computing resources in a pay-as-you-go manner. In a cloud system, resources can be dynamically scaled up and down to the user's on-demand so that the total cost of ownership can be reduced. The Modeling and Simulation (M&S) technology is a renowned simulation-based method to obtain engineering analysis and results through CAE software without actual experimental action. In general, M&S technology is utilized in Finite Element Analysis (FEA), Computational Fluid Dynamics (CFD), Multibody dynamics (MBD), and optimization fields. The work procedure through M&S is divided into pre-processing, analysis, and post-processing steps. The pre/post-processing are GPU-intensive job that consists of 3D modeling jobs via CAE software, whereas analysis is CPU or GPU intensive. Because a general-purpose desktop needs plenty of time to analyze complicated 3D models, CAE software requires a high-end CPU and GPU-based workstation that can work fluently. In other words, for executing M&S, it is absolutely required to utilize high-performance computing resources. To mitigate the cost issue from equipping such tremendous computing resources, we propose HEMOS-Cloud service, an integrated cloud and cluster computing environment. The HEMOS-Cloud service provides CAE software and computing resources to users who want to experience M&S in business sectors or academics. In this paper, the economic ripple effect of HEMOS-Cloud service was analyzed by using industry-related analysis. The estimated results of using the experts-guided coefficients are the production inducement effect of KRW 7.4 billion, the value-added effect of KRW 4.1 billion, and the employment-inducing effect of 50 persons per KRW 1 billion.