• Electric Engineers Magazine
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• v.215 no.7
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• pp.17-21
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• 2000

Hook-On Meter로 중선선전류를 측정하면 큰 전류가 흘러 현장의 담당자를 어리둥절하게 만든다. 대부분의 기술자는 이 경우 누전에 의한 것이 아닌가 하는 의구심을 갖게 되나 실은 영상분 고조파에 의한 것임을 밝혀둔다. 최근 OA기기를 많이 쓰는 빌딩은 전부 이 문제를 가지고 있다. 이 영상분 고조파는 변압기, 케이블, MCCB 과열의 원인이 되고 대지전위상승 등 Noise 원으로 작용해 큰 피해가 우려된다

• Electric Engineers Magazine
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• s.280
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• pp.19-23
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• 2005

전력계통의 사고는 3상 단락에 비해 1선 지락사고가 대부분을 차지하고 있으며 적절한 접지를 통해 대지전압의 이상상승을 억제하고 보호 계전기에 의한 지락고장 검출 고장구간을 자동선택 차단하여 전력기기의 손상과 사고파급을 방지하여야 한다. 그러나 플랜트의 경우, 계통접지방식과 지락보호 시스템에 대한 이해부족으로 상기의 목적을 제대로 만족하지 못하는 사례와 정전으로 인한 2차적인 생산피해도 많이 발생하고 있다. 따라서 본론에서는 계통접지 방식 중에서 비접지 방식의 전반적인 이해를 돕고자하며, 이를 토대로 비접지 계통의 지락보호 협조에 대하여 학습하고자 한다.

• Defense and Technology
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• no.11 s.237
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• pp.76-87
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• 1998

우리나라와 같이 전투종심이 짧고 산악이 많은 지형에서의 저고도에 대한 공중위협은 더욱 가중되고 있어 대공화기의 중요성은 더욱 크다 하겠다. 또한 가장 도발 위험성이 높은 북한과 대치하고 있는 우리의 상황에서 적 공격기의 대지 공격능력 99.5% 이상이 폭탄, 기총, 로켓 공격임을 감안하고 또한 공격헬기를 이용한 대전차 공격과 무인항공기에 의한 위협도 증가하고 있는 추세인 점을 고려할 때 적기의 탐지로부터 격파에 이르기까지의 짧은 반응시간과 야간능력 및 유효사거리 3km내외의 명중률이 뛰어난 무기체계가 필요하게 됨은 자명한 사실이라 하겠다

• Electric Engineers Magazine
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• v.254 no.10
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• pp.34-40
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• 2003

the# star city 신축공사는 철골(판매시설), 철근콘크리트(주거시설)가 병행, 시공되고 대지와의 접촉면이 큰 고층 건축물로 각종의 다양한 전기, 전자, 통신설비 기기가 도입되고 있어 문제가 되는 것이 접지의 시공법이다. 건축물에 있어서 뇌보호란 크게 외부 뇌보호와 내부 뇌보호로 나눌 수 있으며 외부 뇌보호는 직격뢰로 부터 건물등을 보호하는 것이고 내부 뇌보호는 낙뢰시 전위상승으로 인한 영향 및 뇌전류의 전자효과를 저감하는 것으로 특히 과전압 내성이 작은 전자기기 등을 대상으로 하는 보호이다.

• 방재와보험
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• s.131
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• pp.52-53
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• 2009

이번 탐방은 천년고도(古都) 경북 경주시에 위치한 자동차부품 생산공장일 발레오전장시스템스코리(주)를 방문하였다. 승용차와 상용차로 구분된 공장을 대지면적 $101,606m^2$, 건물 연면적 $65,038m^2$규모에 자동차용 발전기, 시동모터, 디스트리뷰터 등을 생산하고 있다. 지난 1999년 프랑스의 세계적인 자동차 전장시스템회사인 발레오에 합병된 이후 현대, 기아, GM대우, 르노 삼성, 쌍용 등에 각종 자동차 전장시스템을 납품하고 있다.

• 방재와보험
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• s.120
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• pp.70-71
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• 2007

세계2위의 규모를 자랑하며, 임진왜란 첫 승전지인 거제도 옥포만에 자리 잡고 있는 대우조선해양을 방문하였다. 130만평의 대지 위에 세계 최대 크기인 900톤 골리앗 크레인과 정규축구장 9개 넓이의 100만톤급 도크 등 초대형 최신 설비를 갖추고 2만 6천 여명의 직원들이 분주히 움직이는 이곳은 작은 도시를 연상시킨다. 기업의 사회적 역할을 다하기 위해 사회공헌활동을 매우 중시하는 대우조선해양은 거제시 재정수입의 30%를 담당하고 있다.

• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.295-299
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• 2012

We performed in vitro assay and field trials to assess levels of changes in intrinsic properties and resistance against soft rot of the potato cv. Dejima upon the introduction of a soybean calmodulin 4 gene (SCaM4). Field trials with four lines overexpressing SCaM4 gene were conducted over two seasons, and harvested tubers were evaluated in bioassay for resistance to Pectobacterium carotovorum ssp. carotovorum. The SCaM4 transgenic potato lines inoculated with $10^8$ CFU/ml of P. carotovorum ssp. carotovorum showed enhanced resistance compared to control. Among the SCaM4 transgenic lines, the transgenic line SCaM4-4 exhibited the highest tolerance to soft rot in vitro assays, so did in field trials. In the field trial, the soft rot resistance of SCaM4-4 line was more than 5 times higher compared to that of control cultivar, Dejima. The major agronomic characteristics of the SCaM4 transgenic lines were not different from those of the nontransgenic 'Dejima'. The result demonstrated that the transformation of a calmodulin 4 gene was a successful strategy in development of potato cultivar enhanced to soft rot.

• Applied Biological Chemistry
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• v.39 no.3
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• pp.212-217
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• 1996

Molecular structural Properties of Potato starches from Irish cobbler(mealy Potato), Dejima(waxy or soggy potato) and Shepody were investigated. iodine reaction of Irish cobbler, Sephody and Dejima starches were 0.45, 0.44 and 0.43. ${\beta}-amylolysis$ limit of the starches was not different between the three potato types. The percentage of each fraction was different among samples : in general, Dejima starch had higher proportion of $F1(more\;than\;{\overline}{DP})$, $F2({\overline}{DP}40{\sim}50)$ and lower proportion of $F3({\overline}{DP}15{\sim}20)$ than those of Irish cobbler starch. When the starch was heated in excess water at $98^{\circ}C$ for 8min, the yield of hot water-soluble starch were higher in waxy type than in mealy one. Each potato variety showed different gel chromatography pattern of the hot water soluble starch. When the potato starches were hydrolyzed with 2.2N HCI at $37^{\circ}C$ for 48 hr, the molecular weight of the starch was decreased.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.254-261
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• 2022

Every vessel shall proceed at a safe speed to avoid collision. Additionally, every vessel shall comply with the speed limit rules in the territorial water and internal waters of Korea. The VTS operator shall properly control the compliance of the vessel with the safe speed and speed limit rules. Safe speed under the COLREG 1972 is not explicitly stipulated in knots. However, under the Domestic law for traffic safety-specific sea areas, etc., the speed limit is specified in knots and complied with. This speed limit rule is mainly based on the 'speed made good over the ground'; however, in some places, it is based on the 'speed making way through the water'. In this paper, I analyzed marine accidents that occurred in the past 5 years and the rate of violation of speed limits. Furthermore, I reviewed safe speed under the COLREG 1972, speed limit rules under domestic and foreign laws, and cases of non-compliance with safe speed in the judgment of the Korea Maritime Safety Tribunal. Resultantly, I suggested in this paper that the speed limit rules in the domestic law must be observed by vessels to prevent marine accidents, and the rules which are stipulated in terms of 'speed making way through the water' must be revised as 'speed made good over the ground' such that the vessels can easily comply with them and the VTS operator can control the vessel properly.

• Economic and Environmental Geology
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• v.57 no.5
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• pp.529-537
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• 2024

Mineral composition used to identify the sedimentary environment can be obtained through X-ray diffraction (XRD) analysis. However, due to time constraints for analyzing a large number of samples, a machine learning-based mineral composition analysis model was developed. This model demonstrated reasonable reliability for samples with usual compositions but showed poor performance for unusual samples. Consequently, a clustering model has recently been developed to classify the unusual samples, allowing experts to handle. The purpose of this study is to examine the applicability of the clustering model, developed using XRD data from the Ulleung Basin in previous study, using samples from different regions. Research data consist of intensity profile from XRD experiment and its mineral composition analysis for a total of 54 sediment samples from the Korea Plateau, located northwest of the Ulleung Basin. Because the intensity of samples in the Korea Plateau comprises 7,420 values (3.005-64.996°), differing from 3,100 values (3.01-64.99°) of samples in the Ulleung Basin, linear interpolation was used to align the input feature. Then, min-max scaler was applied to intensity profile for each sample to preserve the trend and peak ratio of the intensity. Applying the clustering model to the 54 preprocessed intensity profiles, 35 samples and 19 samples were classified into expert and machine learning groups, respectively. For machine learning group, false positive was zero among the 19 samples. This means that the clustering model can increase reliability in when mineral composition from machine learning model because unusual sample did not belong to the machine learning group. For the 35 samples in expert group, the 31 samples were classified as false negative (FN). It means that although machine learning model can properly analyze these samples, they were assigned to expert group. However, when these FN samples were analyzed using machine learning based composition analysis model, a high mean absolute error of 2.94% was observed. Therefore, it is reasonable that the samples were assigned to expert group.