• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.3
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• pp.423-431
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• 2011

Warfighting experimentation is an important process for identifying requirements against changing military environment and for verifying proposed measures for reforming military service. The wargame simulation experiment is regarded as one of the most effective means to warfighting experimentation, and its importance is increasing than ever. On the other hand, the results of wargame experiments could be unreliable due to the uncertainty involved in the experimental procedure. To improve the reliability of the experimental results, systematic experimental procedures and analysis methods must be employed, and the design and analysis of experiments technique can be used effectively for this purpose. In this paper, AWAM, a wargame simulator, is used to optimize the organization of operational troops. The simulation model describes a warfighting situation in which the 'survival rate of our force' and the 'survival rate of the enemy force' are considered as responses, 'the numbers of weapons in the squad' as control factors, and 'the uncontrollable variables of the battlefield' as noise factors. In addition, for the purpose of effective experimentation, the product array approach in which the inner and outer orthogonal arrays are crossed is adopted. Then, the signal-to-noise-ratio for each response and the desirabilities for the means and standard deviations of responses are calculated and used to determine a compromise optimal solution. The experimental procedures and analysis methods developed in this paper can provide guidelines for designing and analyzing wargame simulation experiments for similar warfighting situations.

• Journal of Navigation and Port Research
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• v.40 no.1
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• pp.21-26
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• 2016

Even in the marine industry was required the looser positioning performance as compared to other application domain, a high-quality positioning performance and reliability are becoming ever more important. The high-quality performance includes not only accuracy but also integrity, continuity, and availability. However, current DGPS service is not satisfying the minimum positioning performance requirements for maritime user proposed by IMO. Especially, no one can guarantee the required integrity performance by DGPS service. This paper presents the advanced monitoring concept to strengthen the performance of current DGPS through the enhanced monitoring, guarantee and notice functions. To this, the limitations of the integrity monitoring function of current DGPS are analyzed, and a countermeasure is prepared to improve the limitations of the current integrity monitoring function. This paper can be applied as basis research to improvement of the DGPS service.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1857-1863
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• 2012

The VDS(Vehicle Detection System) collects and transfers information about traffic situations in real time, therefore it makes the traffic management effective. Recently, the VDSs have provided good stability and accuracy in regard to system reliability and functions but they also have showed problems such as raising costs and consuming times when a new system is installed and/or the environmental requirements for the system are set up. The reason of the problems is that up to now the collection of the data and information about the traffic situations has been achieved by the 1:1 information exchange between the traffic control surveillance center and the each traffic field, between equipments and centers, and among data processing equipments and also centers. The communication systems used in the VDS are generally composed of 1 : 1 connection of the lines because the communication protocols are different in the most of the cases mentioned above. Consequently, this makes the number of communication lines become larger and causes the cost for the whole traffic information systems to increase. In this paper, a development of a controller to unify the communication protocols for the VDS is peformed to solve the problems which were mentioned above. Specially, the controller developed in this paper was applied to a radar vehicle detector and tested to show its usefulness. In addition to that, the developed controller was also designed to include functions to transfer the information about weather conditions on the roads.

• Korean Institute of Interior Design Journal
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• v.23 no.4
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• pp.257-266
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• 2014

This study has been performed to come up with any rational way for responding to the functions of fire-fighting spaces newly required by the changing social paradigms and to seek for the approach to designing fire-fighting spaces by taking into account the psychological and behavioral factors of fire-fighters who are exposed stress of operations. In particular, it is to satisfy any physical and functional requirements as special working-spaces and to reflect the psychological and behavioral approach to the workers who are forced to be at standby for a long time, which is the characteristic of their operation, to designing. Accordingly, for fundamental appreciation of whether or not such space programs as space organization needed for operational function are being practiced actively, the fire-fighting headquarters of Incheon City has been selected for the research. First, in the process of assessing the trend of organizing the space at safety centers for the recent 20 years, those built more than 20 years ago were left out from the space selection for the research. Second, those with less than 20 operators also were excluded. Third, among those completed in the same year, only one was selected, which was to avoid overlapping, with the consideration its regional representative nature for applying the safety centers in the jurisdiction of the headquarters equally. The study was performed through the visits to and the actual inspections by surveys at the selected 119 Safety Centers as well as the reviews of literature based on case studies. And for the assessment of significance, surveys and analysis of reliability and factors were carried out. The actual users of Safety Centers were picked as objects for the assessment of significance of space factors at 119 Safety Centers, which revealed that there are five types of dimensions for factor-analyzing standard with which users estimate any significance, which are "Area of Mobilization Preparation and Return" "Area of Standby" "Area of Working Activities" "Area of Employ Welfare" and "Area of Support".

• Journal of Korean Clinical Nursing Research
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• v.18 no.2
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• pp.183-195
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• 2012

Purpose: This study was performed to identify the variations of nursing care cost depending on nursing care requirement and calculate nursing care cost per one day and one care requirement point. Methods: Nursing care requirement was measured by classifying 3,855 patients according to KPCS-1(Korean Patient Classification System for nurses-1). Nursing care cost was calculated from personnel expenses and nursing care requirement. Nursing cost factors were identified by multiple regression analysis. Results: Average nursing cost per patient per day was 33,588 won, Average nursing care cost per 1 patient classification score was 3,558 won. The nursing cost per 1 patient classification score was different depending on the types and levels of the hospitals. The 4th patient classification group revealed the highest nursing care cost. Nursing cost factors included the number of beds in the hospitals, seniority, number of nurses and first grade in nurse personnel accreditation ($adj-R^2$ 74.0%. p<.05). Conclusion: Nursing care requirements expressed by patient classification scores don't directly correlate with nursing care cost. Further research is needed to evaluate validity and reliability for refining KPCS-1 and to apply variable criteria to nurse personnel accreditation.

• Geomechanics and Engineering
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• v.5 no.4
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• pp.363-377
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• 2013

Any structure constructed on the earth is supported by the underlying soil. Foundation is an interfacing element between superstructure and the underlying soil that transmits the loads supported by the foundation including its self weight. Foundation design requires evaluation of safe bearing capacity along with both immediate and long term settlements. Weak and compressible soils are subjected to problems related to bearing capacity and settlement. The conventional method of design of footing requires sufficient safety against failure and the settlement must be kept within the allowable limit. These requirements are dependent on the bearing capacity of soil. Thus, the estimation of load carrying capacity of footing is the most important step in the design of foundation. A number of theoretical approaches, in-situ tests and laboratory model tests are available to find out the bearing capacity of footings. The reliability of any theory can be demonstrated by comparing it with the experimental results. Results from laboratory model tests on square footings resting on sand are presented in this paper. The variation of bearing capacity of sand below a model plate footing of square shape with variation in size, depth and the effect of permissible settlement are evaluated. A steel tank of size $900mm{\times}1200mm{\times}1000mm$ is used for conducting model tests. Bearing capacity factor $N_{\gamma}$ is evaluated and is compared with Terzaghi, Meyerhof, Hansen and Vesic's $N_{\gamma}$ values. From the experimental investigations it is found that, as the depth of sand cushion below the footing ($D_{sc}$) increases, ultimate bearing capacity and settlement values show an increasing trend up to a certain depth of sand cushion.

• Journal of the Korean Society for Railway
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• v.18 no.2
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• pp.111-116
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• 2015

LED luminaires as a lighting system have attracted much research attention due to their high efficiency and long lifetimes. However, disappointing outcomes have been noted in terms of performance levels and lifetimes as compared to desired system requirements in practice due to certain electrical and thermal characteristics of LEDs. LM-80 and TM-21 established by IESNA are the best known standards for lifetime test procedures and estimation techniques. However, they only handle LED light sources without guaranteeing the LED luminaire in a reliability test. They also operate for more than 6,000 hours and undergo various stresses, such as the operating current and temperature. Therefore, a lifetime standard for LED luminaires has not yet been established. This paper proposes a conceptual design of a lifetime test system for LED headlamps depending on the operating environment. Eventually, this method can assist with evaluations of the validity of lifetime standard tests of LED headlamps.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.4
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• pp.26-33
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• 2012

Please WBAN(Wireless Body Area Networks) is wireless communication of within 3 m radius from inside and outside of the body. WBAN is many uses IEEE 802.15.4 MAC protocol for WBAN MAC protocol requirements. IEEE 802.15.4 MAC protocol applies GTS(Guaranteed Time Slot) allocation scheme for guarantee packet delivery of application which requests QoS(Quality of Service). However, GTS allocation scheme of IEEE 802.15.4 MAC protocol uses FIFS(First In First Service) queueing. So it reduces data transmission reliability and has many problems. Therefore, IEEE 802.15.4 applies not WBAN MAC protocol for emergency data transmission. In this paper, we proposes a priority based MAC protocol for emergency data transmission in wireless body area networks. the proposal MAC protocol sets priority the data. So GTS reqeuest throughput of emergency data increasing and GTS allocation delay of emergency data decreasing.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.527-537
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• 2016

Recent automakers are trying to be more precise with the dimension check and moving parts to guarantee high quality and satisfy customer requirements. The aim of this paper is to investigate the design tolerance suitability of door operating mechanism linked arms, lever, and cam-shaft in a mobile air handling unit. These parts are complicated because doors, arms, lever and cam-shaft are connected nonlinearly in 3D. The current tolerance analysis method poses problems in design analysis because the moving doors are reasonably suitable for the AHU function. The 3-DCS analysis method provided useful results not only in establishing the inspection criteria for the quality control of products but also in enabling economical production. As a result, the vent door had $1.62^{\circ}{\sim}1.72^{\circ}$ and the defrost door had $0.84^{\circ}{\sim}0.9^{\circ}$ for the directly connected arms operating-type. For the lever connected arm operating-type, the foot door had $2.0^{\circ}{\sim}2.24^{\circ}$ tolerance, while the tolerance values satisfied the air flow volume distribution rate criteria in the AHU. Finally, the results have confirmed the design's tolerance suitability by using 3-DCS analysis at the early design stages. Reliability can be achieved by analyzing accumulated tolerance during the sub-parts assembly process and the moving mechanism linked especially by arms, lever, and cam-shaft.

• Nuclear Engineering and Technology
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• v.38 no.7
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• pp.639-656
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• 2006

In order to apply the leak before break (LBB) concept to nuclear piping systems, the dynamic strain aging effect of low carbon steel materials has to be taken into account, in compliance with the requirements of the Korean Standard Review Guide (KSRG) 3.6.3-1. For this goal, J-R tests are needed for a range of various temperatures and loading rates, including dynamic loading conditions. In the dynamic loading J-R test, the unloading compliance method can not be applied to measure the crack growth and direct current potential drop (DCPD) method; this method also has a problem defining the crack initiation point. The normalization method is known as a very useful method to determine the J-R curve under dynamic loading because it does not need additional equipment or complicated loading sequences such as electric current or unloading. This method was accepted by the American Society for Testing and Materials (ASTM) as a standard test method E1820 A15 in 2001. However, it has not yet been clearly verified yet if the normalization method is sufficiently reliable to be applied to LBB. In this study, the basic background of the J-integral, LBB and dynamic loading J-R test are explained, and the current status for dynamic loading J-R test methods are reviewed from the view point of LBB for nuclear piping. In particular, the theoretical and historical background of the normalization method which has received attention recently, is summarized. Recent studies for this method are introduced and future works are suggested that may improve the reliability of LBB for nuclear piping.