• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1995.05a
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• pp.127-138
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• 1995

대형 복합재 연소관 금속 보스용 고강도 알루미늄 합금 7175-T74를 개발하기 위하여, 고순도 7175 합금을 이용하여 링롤 단조법으로 대형링을 제조하였으며, 열처리와 가공 조건을 정밀제어한 특수공정을 적용하여 기존의 재료와 재질 특성을 비교 분석하였다. 분석결과 특수공정의 7175S-T74는 기존의 7175-T74 및 7075-T73에 비해 2차상 입자의 분률이 작고, 동일한 SCC특성(38% IACS) 수준에서 강도와 파괴인성이 동시에 증가한 이상적인 강도-인성-SCC 조합특성을 가졌다. 이는 특수공정에서의 고온열처리에 의한 2차상 입자의 재고용과 그에 따른 석출량 증가 때문이며, 결국 7175 합금, 링롤단조 그리고 T74 특수공정을 조합 적용하면 구조적 신뢰성과 경제성 면에서 유리한 보스용 대형링을 개발할 수 있다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.220-221
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• 2022

선박에선 의료관리자가 선박 의약품의 처방 및 관리를 하고 있으며 이는 대부분 항해사로 지정된다. 항해사의 고유 업무와 전문의료지식 부족으로 의약품 관리가 체계적으로 이루어지지 않고 수기로 기록되는 문제점이 있다. 본 연구에서는 영상인식기반의 선박 의약품 종합 관리 시스템을 개발하여 의약품 관리를 자동화하고 의료관리자의 업무 효율성을 증가시키고자 한다. 시스템은 의약품 용기·포장지를 촬영한 영상으로부터 글자를 인식하는 OCR(Optical Character Recognition) 기술을 활용한 모듈, 바코드를 인식모듈, 사용자가 검색할 수 있는 모듈로 구성되어있으며 선박 의약품을 데이터베이스화하여 전산으로 관리할 수 있다. 또한 시스템을 통하여 의약품 재고 관리를 하거나 의약품의 사용법을 확인할 수 있다.

• The Journal of the Korea Contents Association
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• v.20 no.6
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• pp.26-37
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• 2020

This study examined the status of apartment housing based on the problems of noise and smoking between floors and tried to reflective reconsideration to practice the etiquette of apartment buildings by analyzing their perceptions with big data. The research results are as follows. First, it was confirmed that laws and systems were in place to prevent and solve problems of noise between floors and smoking between floors. Second, local governments and apartments are seeking to solve problems through various activities, but we could see that the problems mentioned above continue to increase. The third, big data analysis results showed that people were divided into four groups of awareness of noise and smoking. Fourth, we could see that the etiquette of apartment housing to solve these problems should presuppose improvement of perception and practicality. We proposed three categories to solve the problem. First, we should practice decorum following changes in the living environment. Therefore, I suggest that continuous research and etiquette book should be published. Second, I think the spirit of mutual respect and consideration is necessary, and suggest the autonomous attention and effort of residents living in apartments. Third, I hope that the etiquette education of apartments will be made in apartments or various educational sites and spread to the culture of living.

• Journal of Radiation Protection and Research
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• v.40 no.2
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• pp.101-109
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• 2015

Alpha spectrometry is typically used for the assessment of uranium particle concentrations and its accuracy can be directly related to the accuracy in which the radiochemical pre-treatment is conducted. Ashing and alkali fusion methods are typically used but the ashing method requires longer analysis time and the alkali fusion method is extremely costly. Therefore, a new pre-treatment method using ultrasonic cleaning was developed and its experimental result was compared against the two conventional methods in terms of pre-treatment time, convenience, cost, and recovery rate of a target material. The results that were obtained by the conventional methods(ashing and alkali fusion) and the new method were compared. Consequently, even though the shorter pre-treatment time was required, the new technique showed almost same recovery rate comparing with two conventional methods. The new method was also featured by its relatively lower cost and a simpler process than two conventional methods.

• Journal of Legislation Research
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• no.54
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• pp.217-259
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• 2018

The Trust Act, which was first enacted back in 1961, was fully revised on 25. July 2011 and enacted on 26. July 2012. The Act is a fundamental norm governing trust relation, so the revision was expected to play an important role to promote trust institutions. However many problems were also revealed after the enactment. The Act has already inherent limitations because the previous discussions were not enough and the amendment process was not meticulously reviewed. Now it is needed to consider the comprehensive amendment of the Act reflecting detailed legal doctrines developed hitherto by the courts and the legal academia. This paper aims to call for the revision of the Act and to propose the ways and the grounds for revision. The purpose of the revision is to rectify obvious errors on several provisions, to minimize legal uncertainty by presenting detailed rules on many issues, to enhance the coherence and consistency between the rules along with supplementing the relevant laws, and to strike a proper balance between the parties.

• Nuclear Engineering and Technology
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• v.16 no.4
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• pp.181-194
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• 1984

The in-core fuel management problem was studied by use of the calculus of variations. Two functions of interest to a public power utility, the profit function and the cost function, were subjected to the constraints of criticality, the reactor turnup equations and an inequality constraint on the maximum allowable power density. The variational solution of the initial profit rate demonstrated that there are two distinct regions of the reactor, a constant power region and a minimum inventory or flat thermal flux region. The transition point between these regions is dependent on the relative importance of the profit for generating power and the interest charges for the fuel. The fuel cycle cost function was then used to optimize a three equal volume region reactor with a constant fuel enrichment. The inequality constraint on the maximum allowable power density requires that the inequality become an equality constraint at some points in the reactor. and at all times throughout the core cycle. The finite difference equations for reactor criticality and fuel burnup in conjunction with the equality constraint on power density were solved, and the method of gradients was used to locate an optimum enrichment. The results of this calculation showed that standard non-linear optimization techniques can be used to optimize a reactor when the inequality constraints are properly applied.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.20-26
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• 1997

This paper examines the influences of mining activities on the concentrations of heavy metals in soils in the vicinity of the Dalsung Cu-W mine, Korea. Geochemical surveys were undertaken in the Dalsung mine area and sampling of surface and subsurface soils was carried out. Samples were prepared using 0.1 N HCI, HNO$_3$-HClO$_4$, and aqua regia, and analyzed for Cd, Cu, Pb and Zn by Atomic Absorption Spectrometry. In addition, soil samples were sequentially extracted to investigate the chemical speciation of heavy metals in soils. Heavy metals are highly contaminated in soils in the vicinity of mining area ranging up to 28 $\mu\textrm{g}$/g Cd, 5000 $\mu\textrm{g}$/g Cu, 2390 $\mu\textrm{g}$/g Pb and 930 $\mu\textrm{g}$/g Zn by the method using HNO$_3$-HClO$_4$. The pollution indices calculated with the permissible levels are up to 49 in surface and subsurface soils, which are considered sufficient to raise environmental problems. However, the heavy metal levels by the method using 0.1 N HCl are not higher than Korean standard for soil contamination. It suggests that analytical methods and soil standard should be re-examined. From the results of the sequential extraction methods for metal speciation, total Cu, Pb and Zn concentrations may be determined by analytical methods using HNO$_3$-HClO$_4$ or aqua regia, and exchangeable phase of those metals by the method using 0.1 N HCl.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.195-206
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• 1991

This paper is concerned with comparison of the first-order reliability methods applied to the assessment of structural safety. For convenience the reliability methods are divided into two categories : the One can explicitly consider the effects of uncertainties in material and geometric variables on those of load effects, say stresses and displacement in the structural analysis procedure and the other one does not. The first method is commonly termed as the stochastic finite element method(SFEM) or probabilistic finite element method(PFEM) and the second method is termed heroin as the ordinary reliability method to distinct it from the stochastic finite element method in which the structural analysis is carried out just once and the load effects are directly input into the reliability analysis procedure. This is based on the reasonable assumption that the level of uncertainties of load effects is the same as those of load itself. In this paper the above two different reliability method have been applied to the safety assessment of plane frame structures and compared thier results from the view point of their efficiency and usefulness. As lear as results of the present structure models are concerned, it can be said that the ordinary reliability method can give reasonable results when the uncertainties of material and geometric variables are comparatively small, say when less than about 15% and the stochastic finite element method is desired to be applied to the structure in which the COV's are comparatively great, say when greater than about 15%.

• Korean Business Review
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• v.17 no.2
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• pp.1-23
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• 2004

Since revision of Korean GAAP on the merge transaction in 1999, the few studies on the problems of the GAAP or on the inconsistency of GAAP and regarding tax regulations have been performed. The objective of this study is to understand the present state of the merge transactions, to find out the problems on the regarding GAAP and tax regulations, and to suggest the method to improve them. Among the 69 merge transactions of the listed and registered companies for the recent 3 years, 67 merge transactions are reported as the purchase transactions and 2 transactions as the pooling of interest. And 11 transactions occurred between parents and subsidiaries. I investigate the sufficiency of the foot disclosures on the merge transactions, I find out that the disclosure on the amortization of the negative goodwill are not sufficient, and several transactions are not recorded in conformity with GAAP. This paper indicates the problems on the GAAP as follows: the complicated and irrational method of amortization of the negative goodwill, the valuation of the stocks acquired before the merge, the inconsistent adjustments to purchase consideration contingent on future events, and the valuation of the merge between the parents and subsidiaries. And the problems on the tax regulations are as follows: tax deferment of the income from merge valuation, the ambiguous definitions of the fair value, and stock dividend of the income from merge valuation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.3 no.3
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• pp.91-97
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• 1979

Boundary layer equations (partial differential equations) can be transformed to ordinary diffential equations with constant coeffieients in terms of similarity transformed to ordinary differential equations with constant coeffieients in terms of similarity transformations in the heat tranfer analysis on the surface of any axiaymmetric boiles. The azimuth functions can not be uniquely determined because of the singular behavior at the stagnation point(X=0.deg.).In spite of the azimuth functions behaving singularly, many of researchers have analyzed the heat transfer problem on a horizontal chlinder or a sphere, supposing the set of solutions( $H_{1}$ & G$_{1}$) of being yieled from the simple differential equation to be unique solution of therazimuth functions. In order to ascertain whether mathematical incompatibility as mentioned above can be admitted in the viewpoint of enginerring or not, condensation heat transfer coefficients on a sphere are computed for all azimuth functions( $H_{1}$ G$_{1}$ & $H_{2}$ G$_{2}$) and comparisons with the experimental result are discussed.