• Journal of Korean Institute of Industrial Engineers
• /
• v.20 no.2
• /
• pp.39-50
• /
• 1994

Most research results on the throughput of unit-load automated storage retrieval (AS/R) systems assume the randomized storage; that is, all slots In the entire rack are equally likely to be selected for the storage location. However, for the most existing AS/R systems which use Closest Open location storage policy, Park[6] mathematically showed that this assumption results in a significant difference from the actual performance of AS/R systems. In this study, we present more details about the performance of the unit-load AS/R systems by considering the rack utilization and rack density; and examine their impact on the throughput of AS/R systems by using computer simulation. A new storage policy named Shortest Cycle Location(SCL) is proposed. Simulation results indicate that the performance of SCL policy consistently outperforms the Closest Open location storage policy. We also define the "Extra-Cost Zone" compared to the "No-Cost Zone"[3] and explore its geometric and practical meaning.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2001.11a
• /
• pp.93-99
• /
• 2001

광원별로 형광등 32W 3등을 사용한 터널과 고압나트륨 램프 100W를 사용한 터널, 그리고 저압나트륨 램프 36W와 91W를 혼용한 터널의 조도 및 휘도를 측정한 결과 조도 및 휘도의 균제도는 3 가지 광원이 모두 거의 일치하였으나, 평균 조도와 정균 휘도값에 있어서 저압나트륨 램프를 사용한 터널이 절반 수준이 되는 차이를 보였다. 또한 경제성 평가 도구인 WEELS를 이용하여 터널의 길이를 300[m], 터널 폭을 10.7[m]로 일정하게 하여 경제성을 평가한 결과, 연간 비용에 있어서 고압나트륨 100W가 비용이 가장 켰고, 그 다음이 형광등 32W 3등용, 그 다음이 저압나트륨(36W+91W)이었지만 그 값은 근소한 차이였다.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.2
• /
• pp.291-295
• /
• 2000

A 22-year-old man is presented with 3 months' history of dull pain on the lower thoracic area. Imaging studies suggested osteoid osteoma of 11th thoracic spine, which was verified pathologically after en bloc resection through transfacetal approach. The patient's preoperative pain was resolved immediately. We emphasize the importance of early diagnosis and complete surgical excision of tumor nidus.

• Journal of Korean Neurosurgical Society
• /
• v.45 no.4
• /
• pp.249-252
• /
• 2009

We report on a case of thrombosis of the left common iliac artery following anterior lumbar interbody fusion (ALIF) of L4-5 in a 79-year-old man with no previous medical problems, including peripheral vascular disease. After completing the ALIF procedure, the surgeon could not feel the pulsation of the left dorsalis pedis artery, and the oxygen saturation ($SaO_2$) had fallen below 90% from pulse oxymetry on the left great toe. Thrombectomy was successfully performed after confirming the thrombus in the left common iliac artery using Computed Tomography (CT) angiography. Thrombosis of the common iliac artery is very rare following ALIF. However, delayed diagnosis can lead to disastrous outcome. Although elderly patients have no cardio-vascular disease or vessel calcification in pre-op evaluation, the possibility of a complication involving L4-5 should be considered.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.10a
• /
• pp.315-318
• /
• 2009

Electric shock is the accident caused by the current through a person or animal's body. That is characterized by the physiological effects. In this paper, we evaluate performance of protection against electric shocks for TT and TN grounding systems which are used by a low voltage consumer nowadays. The performance of protection against electric shocks for TT grounding system is very excellent in equipotential area of the third class grounding, but the performance is poor outside the equipotential area. The performance of protection against electric shocks for TN grounding system is excellent because the potential difference is less than 50V. Accordingly, the performance of protection for TN grounding system is good as compared with that for TT grounding System.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.509-510
• /
• 2011

한국전력공사 배전선로의 가공설비(특고압)는 2011.03 현재 약 615,089 km가 설치 운전 중에 있으며 해마다 가공전선 단선 고장이 일어나고 있어, 원인 규명 및 방지대책을 강구하고 있다. 본 연구에서는 가공전선 단선사고의 일반적인 사례 LP 애자 설치개소가 아닌 선로 중간에서 단선 고장난 사고사례에 관한 것으로써 전선피복(절연체)의 두께와 impulse voltage에 따른 Pinhole 형성 그리고 단선 메커니즘에 대해서 기술하였다.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.404-405
• /
• 2011

In this paper, we present basic modeling of Juju power system using PSCAD/EMTDC. In detail, models of bipolar HVDC system, power transmission line, basic thermal power plant, load, and wind farm have been developed for Jeju power system. For evaluating basic dynamic behavior, we tested the system with a simple scenario and the test result showed acceptable response.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.559-561
• /
• 2011

송전선로 건설시 적용해 왔던 이도측정 방식에 대하여 정확성이나 효율성면에서 기존의 방식보다 우수한 측량방법을 개발하여 현장에 적용할 필요가 있으며, 그 대안으로 광파기를 활용한 이도측정방법이다. 신공법 적용에 따른 여러 가지 문제점도 발생하고 있어 현장에서 개선방안을 도출하였으며 모터가 부착된 측량기내에 프로그램을 내장하여 누구나 쉽게 현장에서 이도를 측정 할수 있게 되었다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2005.05a
• /
• pp.248-253
• /
• 2005

Although DC ground resistance is a good index of grounding performance for grounding electrodes, it does not reflect the grounding performance during transient state. Besides, impulse ground impedance, which is defined by a ratio of the peak value of transient ground potential rise to the peak value of impulse current, cannot be an absolute index due to its dependence on impulse current shape. In this paper, ground impedance of various rod-type ground electrodes has been measured in frequency domain ranging from 1 Hz to hundreds of kHz. Equivalent circuit models of the ground rod have been identified from the measured values of ground impedance in frequency domain.

• Journal of radiological science and technology
• /
• v.2 no.1
• /
• pp.100-100
• /
• 1979

For eighteen months from May, 1977, to November, 1978, I found out the following conclusion with the references when the author had the test of Lymphangiography for malignant lymphoma and cervix cancer of uterus who had the suspicion of nodal metastasis who amounted 56 patients. 1. According to the test 40 patients among 56 were succesful, almost 71% of t-them, injecting needles at both pedis, and it showed some technical difficulties in Lymphangioraphy comparing with other diagnostic measure. 2. As the result of Lymphangiography of 56 patients, they complained pains, edema of foot. In the course of finding out lymphatic vessel there was exudation due to high pressure at the insected part. At the process and at that test there have been frequent complains by the patients about some sort of pains and some times severe pains.