• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.269-271
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• 2003

A method for calculation of mutual inductance from the parallel power-line and earth conduct to communication-line is studied in the paper. The solution for the electromagnetic field produced by an overhead power-line is derived using Maxwell's equations and treating the as a boundary value problem. Total mutual inductance from direct current and image current to communication-line is used Carson's formula for infinitely long parallel conductors.

• 소음진동
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• 제9권2호
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• pp.331-339
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• 1999

This paper presents the simplified formulas for calculating the fundamental frequencies of the cantilevered bellows in the axial and lateral directions. The frequencies of the bellow are evaluated based on analogies with those of the beam. It is shown that the results calculated by the simplified formulas are in good agreement with those obtained from FEM analysis and the experiment.

• 한국방재학회 논문집
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• 제7권5호
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• pp.151-158
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• 2007

인천연안도서지역 소하천의 홍수도달시간을 산정하기 위하여 영흥도의 9개 소하천을 대상으로 11개 지점에 수위표를 설치하고 실제 강우사상에 대하여 유량을 산정하였다. 실무에서 주로 사용되고 있는 홍수도달시간공식을 이용하여 유량산정 지점별 홍수도달시간을 산정하였으며, 유입시간을 고려하기 위하여 3가지 방법으로 비교하였고, 도표에 의한 방범을 채택하였다. 유출모형을 이용하여 산정된 첨두홍수량 발생시간과 관측된 첨두유량 발생시간을 비교 분석하였다. 연안도서지역에 적합한 도달시간공식으로 Kirpich공식을 채택하였으며, 통상적으로 알려진 Kirpich공식의 적용범위가 유역면적 $0.453km^2$이하로 하도경사 $3{\sim}5%$까지 였으나, 본 연구를 통하여 유역면적을 $2.0km^2$까지 확대하고 유역면적 증가에 따라 하도경사도 1.5%까지 확대 사용 가능하도록 적용범위를 확대하여 제안하였다.

• 수산경영론집
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• 제25권1호
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• pp.1-17
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• 1994

Coastal economic activities usually generate externalities to other economic activities. The conflicts between coastal economic activities, especially land fillings and reclamations, and fisheries in coastal waters pose a typical one, which sometimes causes some social conflicts. In this regard, as the contents and requirements for rules and regulations on fisheries compensation may have important implications for solving such problems, important is to review rationales fur the formulas in calculating fisheries compensation. The purpose of this paper is to review the formulas for fisheries compensation from the economic view points, to highlight some problems and to suggest more appropriate formulas. It is found that the current formulas of fisheries compensation are not properly based on economic concepts and valuation techniques. Main problems are related, as followings, to the coefficient(0.8) employed in the formula, to fishermen's own wages and to current values of invested assets such as fishing boats and nets, etc.. First, it is not clear what the coefficient(0, 8) means. In Japan's case, the coefficient was assumed to reflect the opportunity cost of fishermen's own wages, but it was disappeared from the formula after the self-wage came to be included in totaling fishing cost. As our new formula will include the self-wage in fishing cost, the coefficient(0.8) should be excluded. Second, according to our formula, the current value of invested assets is added to total operating compensation, which will overestimate total compensation. Therefore, it is suggested that total present value of the assets to be invested during the business life should be deducted from total operating compensation. Third, as the self-wage will be included in total cost, opportunity cost for finding new jobs should be newly added to the formula. Finally, this paper also conducted a comparative case study considering above-mentioned factors. The case study showed that the current formulas overestimated total fisheries compensation.

• 한방비만학회지
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• 제7권1호
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• pp.39-54
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• 2007

Objectives : This study has been done to know which herbs and herbal formulae are frequently used for the treatment of obesity in Korea and overseas since 2000. Methods : We conducted a computerized literature search in KISS (Korean studies Information Service System), Pubmed, Journal of Oriental Association for Study of Obesity ,and Journal of Oriental Rehabilitation Medicine(2000 -Apr. 2006) using search key words obesity, obese, weight loss, weight control combined with herb, herbal formula. Result and conclusion : Seventy-two studies have been identified(50 Korean papers and 22 pubmed papers) and 81 herbs have been found. In USA it was mainly used as single herb for food, but in Korea it was mainly used as herbal formula. For single herb, ephedra(麻黃) was the most studied single herb both in Korea and the USA. For herbal formulae, Sasang Constitutional Medicine(SCM, 19times) was the most frequently used herbal formula, in which the herbs for Tae-eum type person like Taeyeumjowui-tang(太陰調胃湯, 7times) and Choweseungcheng-tang(調胃升淸湯, 5times) were mainly prescribed. The next was Chegameuiin-tang(體減薏苡仁湯, 11times) and Bangpungtongsungsan( 防風通聖散, 3times). Calculating each herb consisted in each herbal formula, Coicis Semen(薏苡仁), Angelicae gigantis Radix(當歸), and Glycyrrhizae Radix(甘草), Raspberry Ketone, Cnidii Rhizoma(川芎), and Ephedra Herba(麻黃) turned out to be the most frequently used herb.

• 조명전기설비학회논문지
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• 제17권3호
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• pp.119-126
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• 2003

공항과 같이 간선이 길게 포설될 수 있는 장소의 저압간선 굵기는 해당 케이블의 허용전류와 전력계통의 전압강하를 고려하며 결정된다. 비록 도체의 허용전류 값이 부하의 허용전류 값에 비하여 여유가 있을지라도 계통의 허용전압강하를 고려할 경우 도체의 굵기는 비교적 크게 산정될 수 있다. 이러한 경우에, 도체의 허용전류 값은 부하의 최대전류 값보다 훨씬 크게 산정될 수 있으며 상대적으로 도체에서 발생되는 열은 감소하게 된다. 도체의 최대 허용온도에 보정된 도체의 교류저항 값이 저압간선의 굵기 산정을 위한 전압강하 계산공식에 적용되어 왔으며, 도체의 저항 값은 도체의 실제 온도상승 값이 적용된 저항 값에 비하여 크다 본 연구는 도체의 실제 온도상승 값이 보정된 도체의 저항 값을 적용하여 저압간선 굵기 선정 설계 실무에 적용할 수 있도록 일반적인 계산 방식에 비하여 오차가 적은 경제적인 설계 방식을 연구하였다.

• 한국재난정보학회 논문집
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• 제19권1호
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• pp.31-43
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• 2023

연구목적: 본 연구에서는 탄소성해석과 수치해석의 차이점 분석과 해석 결과치의 유사한 경향을 도출하기 위한 설계지반정수 재산정 방법의 연구를 수행하였다. 연구방법: 얕은굴착과 깊은굴착에 따라 벽체변위가 같아지는 시점에서의 지반반력계수와 지반변형계수의 관계식을 유도하였다. 연구결과: 계측결과를 바탕으로 역해석을 진행하여 현장지반에 맞는 지반물성을 재산정하고 도출된 식과 문헌식을 이용하여 벽체변위에 대한 비교·검증한 결과 제안식이 가장 유사한 값을 나타내고 있었다. 결론: 제안식을 이용하면 설계시 실제와 가장 비슷한 지반물성치를 유추할 수 있어 실무에 도움이 될 것이다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.36.3-37
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• 2009

This is an attempt to improve a formula to predict variations of geomagnetic storm indices (Dst) from solar wind parameters. A formula which is most widely accepted was given by Burton et al. (1975) over 30 years ago. Their formula is: dDst*/dt = Q(t) - Dst*(t)/$\tau$, where Q(t) is the Dst injection rate given by the convolution of dawn-to-dusk electric field generated by southward solar wind magnetic field and some response function. However, they did not clearly specify the response function. As a result, misunderstanding seems to be prevailing that the injection rate is proportional to the dawn-to-dusk electric field. In this study we tried to determine the response function by examining 12 intense geomagnetic storms with minimum Dst < -200 nT for which solar wind data are available. The method is as follows. First we assume the form of response function that is specified by several time constants, so that we can calculate the injection rate Q1(t) from the solar wind data. On the other hand, Burton et al. expression provide the observed injection rate Q2(t) = dDst*/dt + Dst*(t)/$\tau$. Thus, it is possible to determine the time constants of response function by a least-squares method to minimize the difference between Q1(t) and Q2(t). We have found this simple method successful enough to reproduce the observed Dst variations from the corresponding solar wind data. The present result provides a scheme to predict the development of Dst 30 minutes to 1 hour in advance by using the real time solar wind data from the ACE spacecraft.

• Steel and Composite Structures
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• 제49권2호
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• pp.181-196
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• 2023

Marine structures including offshore wind turbines (OWTs) always work under cyclic loads, which arouses much attention on the fatigue design. The tripod substructure is one of the typical foundation forms for fixed OWTs. The three-planar tubular Y-joint (3Y joint) is one of the important components in fatigue design as it is most likely to have cracks. With the existence of the multiplanar interaction effect, calculating the hot spot stress (HSS) of 3Y joints is complicated. To assist with fatigue design, the distributions of stress concentration factor (SCF) and multiplanar interaction factor (MIF) along weld toe curves induced by the out-of-plane bending moment are explored in this study. An FE analysis method was first developed and verified against experimental results. This method was applied to build a numerical database including 1920 FE models covering common ranges of geometric parameters. A parametric study has been carried out to reveal the distribution patterns of SCF and MIF. After multidimensional nonlinear fittings, SCF and MIF distribution formulas have been proposed. Accuracy and reliability checking prove that the proposed formulas are suitable for calculating the HSS of 3Y joints.

• 한국안전학회지
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• 제29권5호
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• pp.97-103
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• 2014

To ensure durability and light weight of bridges, high-strength concrete is required for long-span deck slabs. Such a technology eventually extends the life of bridges and improves the economic efficiency. The results of this study suggests a formula for calculating the minimum thickness of long-span deck slabs built with high strength concrete. The minimum thickness is proposed based on the limit states indicated in the CEB-FIP Model Code and the Korean Highway Bridge Design Code(limit state design). The design compressive strength of concrete used for the study is 80MPa. Moreover, the required thickness for satisfying the flexural capacity and limiting deflection is estimated considering the limit state load combination. The formula for minimum thickness of deck slabs is proposed considering the ultimate limit state(ULS) and the serviceability limit state(SLS) of bridges, and by comparing the Korean Highway Bridge Design Code and similar previous studies. According to the research finding, the minimum thickness of long-span deck slab is more influenced by deflection limit than flexural capacity.