• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.6
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• pp.1061-1069
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• 1989

본 연구에서는 제조공정을 생략하고, 보다 최종제품의 형상에 가까운 직접압 연법을 실현하기 위한 기초적 연구로서 두개의 회전하는 로울 내부를 냉각하면서 쐐기형 노즐을 통하여 폭이 균일한 용탕을 직접 주입하는 실험방법에 의해서 얻어진 주편의 표면상태와 주조조건과의 관계에 대하여 논하며 또한 기계적성질에 대하여 검토한다.

• Korean Journal of Crystallography
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• v.12 no.1
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• pp.37-54
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• 2001

1960년대까지는 단결정 구조를 해석할 때 주로 Patterson 방법으로 중원자(heavy atom)를 찾고 이 중원자에 의한 위상에 기초하여 구조를 해석해 왔다. 회절점의 위상을 수학적으로 결정하는 직접법(direct method)은 1948년 Harker와 Kasper에 의해서 최초의 논문이 발표된 이후, 50∼60년 대에 이론적 기초가 구축되었으며, 70년대부터 컴퓨터 프로그램화되어 실용되기 시작하였다. 본 해설문에서는 직접법에 사용되는 정규화된 구조 인자(normalized structure factor)와 unitary 구조 인자의 정의를 소개한 후, 직접법의 기본식인 Sayre 방정식으로부터 유도되는 반전적 혹은 대칭중심적(centric)인 경우에서 성립하는 부호 관계(sign relationship) 및 ∑₂-관계(∑₂-relation)와 비반전적(acentric)경우에서 성립하는 탄젠트 공식(tangent formula)의 유도 과정을 설명하였고, 부호 관계와 탄젠트 공식이 필요로 하는 처음 몇 개의 회절점의 위상을 정하는 과정도 보였다.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.416-418
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• 2002

본 논문은 2001년에 도입되어 현재 시행중인 우리나라의 대표적인 부하관리 프로그램인 직접부하제어의 적정 인센티브 수준을 결정하는 새로운 방법론을 제시한다. 기존의 인센티브 수준 결정 방법론이 공급자측을 중심으로 한 회피비용에 기초하여 결정된 반면, 본 연구에서는 참여자인 수용가의 대처비용과 월간요금 지급액의 감액을 중심으로 한 인센티브 결정 방법론을 제안한다. 또한, 이러한 인센티브 결정 방법론의 수학적 정식화를 도출하여 보다 체계적인 분석이 가능하게 하였다. 이러한 접근법은 소비자의 편익 및 비용을 보다 정확하게 분석하고 이에 기초하여 인센티브 수준이 결정되기 때문에 직접부하제어의 활성화에 기여할 것으로 판단된다.

• Product Safety
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• s.184
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• pp.58-63
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• 2009

전기기기에 의해 감전재해는 전기기기의노출된 충전부에 직접 접촉하여 발생하는 경우와 전기기기의금속제 외함 등의 비충전부분이 절연열화 등의 원인으로 누전되었을 경우 접촉하여 발생하는 것이다. 본 고에서는 충전부(LivePart)로부터 인체감전 사고 방지를 방지하기 위하여, 충전부 직접 노출에 대한 안전성을 확보 및 이중구조에서 기초절연의 접촉에 대한 적합성 판단을 제시 하고자 한다.

• Journal of the KSME
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• v.35 no.9
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• pp.829-835
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• 1995

통상의 열교환기에서 전열면이 제거된 형태의 직접열교환을 통하여 제작비나 열전달 특성에 큰 효과를 얻을 수도 있어 에너지이용 합리화에 기여하는 특성과 사례를 언급하였다. 또한 통상의 열교환기 설계와 다른 매질간의 공유계면에서 발생 가능한 전달특성을 위주로 설계상의 일부 유의사항을 기술하였다. 직접열교환의 기술축적은 상변화를 동반하는 열전달(two phase heat transfer) 문제의 기초지식은 물론, 염수플랜트(desalination)의 기본 요소설계, 원자로의 냉각계 통사고(LOCD)대책, 기타 냉각탑, 탱크가열, 증발기(evaporator), 건조장치(drier), 각종 기계, 화공 공정장치 설계 등 매우 광범위한 기술파급 효과도 기대할 수 있으므로 관련 기술자들의 많은 관심을 기대한다.

• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.274-289
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• 2017

The purpose of this study was to examine empirically the influence of self-efficacy on the selection of behavior and sustainability as a variable affecting vocational basic competencies. There is a need to confirm the influence of the mediating effect of nursing professionalism and self-directed learning ability formed through the recognition of nursing professional intuition on the vocational basic competencies. For this purpose, 396 nursing students from three junior colleges in J province were sampled for convenience. All of the latent variables were measured by vocational core competency, self-efficacy, nursing professionalism and self-directed learning ability. The collected data were analyzed using Structural Equation Modeling. The result of this study were as follows: First, the fix indexed of causal model among ocational core competency, self-efficacy, nursing professionalism and self-directed learning ability were identified suitably. Second, self-efficacy had no direct effect on vocational core competency, however, nursing professionalism and self-directed learning ability had moderating effect in the relationship between self-efficacy and vocational core competency. Third, nursing professionalism had direct effect on vocational core competency and also self-directed learning ability had moderating effect in the relationship between nursing professionalism and vocational core competency. Fourth, self-directed learning ability had direct effect on vocational core competency.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.1
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• pp.43-53
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• 2002

Current torsional provisions focus n restricting torsional effect of asymmetric wall structures by proportioning strength of wall based on the traditional assumption that stiffness and strength are independent. Recent studies have pointed out that stiffness of structural wall is dependent on the strength. This implies that actual stiffness of walls can be determined only after torsional design is finished and current torsional provisions may result in significant errors. To overcome this shortcoming, this paper proposes deformation based torsional design for asymmetric wall structures. Contrary to the current torsional provisions, deformation-based torsional design uses displacement and rotation angle as design parameters and calculates base shear for inelastic torsional response directly. Main purpose of deformation based torsional design is not to restrict torsional response but to ensure intended torsional mechanism according to the capacity design concept. Because displacement and rotation angle can be used as performance criteria indicating performance level of asymmetric structures, this method can be applied to the performance based seismic design effectively.

• Journal of Practical Engineering Education
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• v.7 no.2
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• pp.81-87
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• 2015

The Direct Instruction (DI) was applied to the learning-disabled in the basic engineering education (especially, physics education). The DI is specified as an educational method in which the instructor strongly controls during the whole process of the entire course. The tests of understanding, reasoning, memory, and problem-solving speed showed that 20 students (20%) out of random 100 students are learning-disabled. The average points of mid-term and final exams were 53.7% and 61.0% respectively for a certain 41-students class. However, in this class, for the lower point students who obtained less than 50% points, the average points of mid-term and final exams were 29.8% and 28.2% respectively, which showed decreased. From this lower point group, the 8 students (20% students of 41 students) were selected as the learning-disabled. With additional DI studies provided, the average points of mid-term and final exams for the learning-disabled were 18.9% and 25.5% respectively, which showed 6.6% increase that means the DI for the learning-disabled was effective.

• 지반과기술
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• v.11 no.1
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• pp.39-42
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• 2014

• Journal of the Korean GEO-environmental Society
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• v.11 no.4
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• pp.51-59
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• 2010

This article is a case study for the example of the foundation design, in the project area of the silty sand layer that is spread shallowly with loose status, to make the site for a structure and build it up. The site is located on the dredged and reclaimed land in Gun-San and In-Cheon that is formed the silty sand layer with loose status range around 10 meters underground level, the solid ground for the lower pile is shown around 20 meters underground level. Therefore, this area has to be done by ground improvement when applying for the shallow method of foundation. Dynamic compaction method considering the conditions of the design loads in each zone has to be decided through comparative review on the method of foundations and pilot field test was conducted, and drilling investigation and plate bearing test were achieved as well. The analysis results of the tests prove that stability against bearing capacity was acquired by ground improvement effect.