• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 춘계학술대회 논문집
• /
• pp.535-542
• /
• 2002

This paper show communication network scheme problem for the railway is solved which were electrical noise and line break in wayside using rerouting communication line, Considering the availability and the maintainability based on the reliability in design of communication networks. At first, Self-Healing Ring algorithm is suggested in that solution which is satisfied with above requirements. And also, in the advanced type, Dual Master scheme is suggested that the problem which is occurred in line break of both main and sub line at the same time can be solved using DMSHR(Dual Master Self Healing Ring). Therefore total reliability in railway system is going to be advanced using DMSHR scheme.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 하계학술대회 논문집
• /
• pp.169-172
• /
• 2000

In this paper, we evaluated the mechanical and dielectric properties of LDPE depend on $Co_{60}$${\gamma}$-irradiation doses. The chemical analyses for FT-IR, gel content, the mechanical properties for elongation at break and the dielectric parameters for permittivity, tan$\delta$ were discussed as a function of irradiation doses. Test result presented that elongation at break of irradiated LDPE was inversely proportional to gel content. For dielectric analyses, permittivity showed a salient characteristic for various irradiation doses, it was related to polar groups caused radiation degradation and tan$\delta$ of irradiated LDPE increased with irradiation doses.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.179-182
• /
• 2002

XLPE compound have used for insulation of 22.9(kV) power cable. But tree retardant power cable has developed and is going to br used commonly. TR XLPE compound retard production and growth of water tree. In this paper, tensile strength, elongation at break, degree of crosslinking, lightning impulse test, AC breakdown test, cyclic aging for 14days and accelerated water treeing test of TR XLPE insulated power cable were examined according to the KEPCO buying spec. & AEIC CS 5-94 standards. before and after As the result, tensile strength, elongation at break and degree of crosslinking test results of TR XLPE insulation were higher than requirement values. After accelerated water treeing test for 120 days, 240 days and 360 days, AC breakdown voltages were not decreased for accelerated water treeing aging duration

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.86-88
• /
• 2005

The line-start permanent magnet synchronous motor has a high efficiency and an advantage in constant speed operation regardless of the effect of load variation. However it is difficult to predict the performance of characteristics accurately, because of the unbalanced starting torque with the initial starting position of the rotor and the generation of a break torque. In this paper the dynamic characteristics of the line-start permanent magnet synchronous motor arc described and compared with those of the squirrel-cage induction motor through the simulation to find the characteristics of the permanent magnets and the rotor bars in the line-start permanent magnet synchronous motor.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 추계학술대회논문집
• /
• pp.554-558
• /
• 2004

In this paper, we introduce noise prediction program of HVAC system to assist low-noisy design of ship's cabin. The developed program calculates sound power levels at HVAC components considering primary and secondary noise generated by fan and duct element, duct element noise attenuation, and duct break-in noise based on the authentic empirical method suggested by NEBB and acoustic power balancing method. Sound pressure level at cabin with or without ceiling system is evaluated by the diffuse-field theory considering diffuser and duct break-out sound powers. Moreover, the program provides intuitive pre- and post-processors using modem GUI functions to help efficient modeling and evaluation of cabin and HVAC component noise. To validate the accuracy and convenience of the program, noise prediction for a HVAC system is demonstrated.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 하계학술대회 논문집 A
• /
• pp.554-556
• /
• 2004

Testing capacity of KERI synthetic short-circuit testing facilities has been upgraded to fulfill the requirements up to 550kV 63kA, 1-break circuit breaker ratings. Specially the current capacity was increased 50kA to 63kA and the full type test of 362kV 63kA circuit breaker(1-break) was firstly completed in domestic. UP to now, domestic manufacturers have depended on the foreign testing laboratory for performance verification of newly designed products. This paper introduces the summary of the increased short-circuit testing facilities, the testing techniques and its results for the making and breaking performance of 362kV, 63kA circuit breaker which was Performed according to IEEE C37.06(1999) used in North America.

• Nuclear Engineering and Technology
• /
• 제55권2호
• /
• pp.623-639
• /
• 2023

The specific configuration of the safety systems in VVER-1000/V320 reactors allows a comprehensive study of the Loss of Coolant Accident (LOCA). In the present paper, a verification of the success criteria of the event trees headers for the medium and large break LOCA sequences is conducted. A detailed TRACEV5P5 thermal-hydraulic model of the reactor has been developed, including all safety systems. When analyzing the results of all sequences, some conservatism is observed in certain specific configurations as the success criterion of some headers is not consistent with the classic PSA level 1. Therefore, new proposals for the LOCA event trees are performed based on a reconfiguration of LOCA break ranges and the use of the expanded event trees approach.

• 노동경제논집
• /
• 제35권1호
• /
• pp.89-109
• /
• 2012

본 연구는 실업률 변화와 성장률 간의 경험적 관계를 나타내는 오쿤의 법칙을 우리나라의 자료를 이용하여 추정하고 그 결과를 새롭게 해석하는 것을 목표로 하고 있다. 분석 결과는 다음과 같다. 첫째, 벤치마크 오쿤의 추정계수 ${\beta}$는 방법론에 따라 대략 2~4의 계수 값을 보여주어 선진국의 경우보다 다소 높은 값을 보여주었다. 둘째, 경기변동에 따른 비대칭적인 반응이 관측되기는 하지만 추정방법에 따라 혼재된 결과를 보여주고 있다. 마지막으로 1979~80년, 1997~98년 등의 구조변화를 반영한 오쿤의 추정계수는 벤치마크와 비슷한 값으로 추정되었다.

• 대한기계학회논문집A
• /
• 제20권6호
• /
• pp.1872-1881
• /
• 1996

LBB(Leak-Before-Break) analysis is performed for the highest stress location of each different type of mateerials in the nuclear piping line. In most cases, the highest stress occurs in the pipe and nozzle interface location. i.e. terminal end. The current finite element analysis approach utilizes the symmetry condition both for locations near the nozzle and for locationa away from the nozzle to minimize the size of the finite element model and to make analysis simple when calculating the J-integral values at the crack tip. In other words, the nozzle is not included in the finite element model. However, in reality, the symmetric condition is not applicable for the pipe-nozzle interface location. Because the pipe-nozzle interface location is asymmetric due to different stiffenss of the pipe and nozzle(both material and dimensions). The simplified analysis approach for pipe-nozzle interface locaiton is too conservative for a smaller diameter piping. In tlhis paper, various analyses are performed for the range of materials and crack sizes to evaluate the nozzle effect for a LBB anlaysis. This paper presents methodology for developing the piping evaluaiton diagram at the pipe-nozzle interface location.

• 한국컴퓨터정보학회논문지
• /
• 제17권10호
• /
• pp.167-173
• /
• 2012

본 연구의 목적은 직장에서의 업무 외적인 활동에 대하여 조사하는 것이다. 이를 위하여 업무시간 중 업무 외적인 커피 브레이크 및 스마트폰 사용, 그리고 소비한 시간을 보충하기 위한 수당지급 없는 야근이 성과에 미치는 간단한 이론모형을 개발하고 분석하였다. 분석결과, 첫째 업무시간 중 업무외 목적의 오프라인 커피 브레이크는 성과에 긍정적인 영향을 미치는 것으로 나타났다. 둘째, 업무시간 중 업무외 목적의 스마트폰 사용은 성과에 부정적인 영향을 미치는 것으로 나타났으나, 직장 동료와의 의사소통에서는 성과에 긍정적인 영향을 미치는 것으로 밝혀졌다. 셋째, 업무시간 중 업무 외적으로 소비한 시간 보충을 위해 하는 수당지급 없는 야근은 성과에 부정적인 영향을 미쳤다.