• 대한조선학회논문집
• /
• 제45권4호
• /
• pp.441-454
• /
• 2008

Shipyard design and equipments layout problem, which are directly linked with the productivity of ship production, is an important issue serving as reference data of production plan for later massive production of ships. So far in many cases, design of a shipyard has been relying on the experienced engineers in shipbuilding, resulting in sporadic and poorly organized processes. And thus, economic losses as well as trials and errors in that accord have been pointed out as inevitable problems. This paper extracts a checklist of major elements to fine tune the shipbuilding yard designing process and the input/output data based on the simulation based shipbuilding yard layout designing framework and methodology proposed in existing researches, and executed initial architecture to develop software that integrates all the relevant processes and designing tools. In this course, both user request and design data by the steps are arranged and organized in the proposed layout design template form. In addition, simulation is done based on the parent shipbuilding process planning and scheduling data of the ship product, shipbuilding process and work stage facilities that constitute shipbuilding yard, and design items are verified and optimized with the layout and equipment list showing optimal process planning and scheduling effects. All the contents of this paper are based on simulation based shipbuilding yard layout designing methodology, and initial architecture processes are based on object oriented development methodology and system engineering methods.

• Journal of the Korean Wood Science and Technology
• /
• 제31권2호
• /
• pp.31-37
• /
• 2003

목재의 결함을 탐지하는 비파괴 진단법 중에서 초음파를 이용한 비파괴 시험법은 그 경제성과 사용에서 큰 장점을 지니고 있어, 그 활용과 관련된 연구가 활발히 진행 중이다. 그러나 현재까지의 연구는 입목 또는 원목 등과 같이 비파괴 평가를 위한 측정이 비교적 적은 경우에 국한되어 있어, 목조 문화재 등을 비롯한 구조물의 부재와 같이 부재의 일부 면만을 측정할 수 있는 경우에 대한 연구가 미비한 실정이다. 따라서 본 연구에는 이러한 초음파 시험기의 측정방법의 제한을 극복하는 방법을 모색하고자 그 첫 번째 단계로 결함을 갖는 목재 내에서 초음파 전달 경로를 구명하고자 하였다. 다양한 전달 경로 모델을 가정하고 실제 실험과 비교를 통해 초음파 전달의 가장 적합한 모델을 제시하고자 한다. 실험 시편에 인위적인 결함을 만들어 실험한 결과 초음파가 직접 전달될 수 없는 부분의 경우 그 결함을 피해서 전달되고 전달 경로는 탐촉자의 반대 측면에서 일차반사를 통해 전달되는 것으로 판단되었다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• 제20권3호
• /
• pp.122-128
• /
• 2009

Objectives : Autism is a well-known psychiatric disorder that is presumed to have a neural basis. To investigate the underlying neurofunctional abnormalities of autism, the authors performed single photon emission computed tomography (SPECT) on children with autism. Methods : Fifty-five children with untreated autism (47 boys and 8 girls, mean age=$50.6{\pm}20.28$ months) were selected from among the patients visiting the child and adolescent psychiatric clinic of Seoul National University Hospital. Psychiatrists had diagnosed the participants according to the DSM-IV criteria for autistic disorder and the Childhood Autism Rating Scale (CARS) criteria for a diagnosis of autism. All participants were examined using 99mTC-HMPAO Brain SPECT. Using statistical parametric mapping (SPM) analysis, we compared the participants' SPECT images to standardized SPECT images of normal children, which had been retrospectively selected by the authors, on a voxel by voxel basis. Voxels with a p-value less than .001 were considered to be significantly different. Results : The autistic group showed significant hypoperfusion in the right medial frontal gyrus, right precentral gyrus, and left precuneus gyrus. In addition, they showed no significant hyperperfusion areas when compared to the control group. Conclusion : The findings of hypoperfusion in the medial-frontal lobe and precuneus are accord with hemodynamic abnormalities that have been already reported. Therefore, these findings are compatible with the recently suggested "theory of mind" hypothesis and the disturbances in attention shifting that have been observed in autistic children.

• 대한간호학회지
• /
• 제36권1호
• /
• pp.197-205
• /
• 2006

Purpose: The objective of the study is to analyze the review contents of reviewers for the submitted papers in the Journal of Korean Academy of Nursing in 2003. Method: The review contents of the 165 papers were selected 217 papers that were submitted in 2003. Among those 165 papers, the 21 papers belonged to the 'Do not publish' list and 17 papers, 'Revise manuscript and resubmit', list and the 94 papers, 'Publish if revisions are made' list. There are more than two level differences among the four levels of decision in acceptance of publication in 33 papers. Results: The analysis of the review contents for the papers were suggested according to review categories: introduction, method, results, discussion and conclusion. In addition, if papers had more than two levels of review they were rated poor accord or inconsistent. Conclusion: For the quality of the academic journal and development of the nursing science, it is important to disseminate and publish the research paper. Therefore, review of the submitted paper is also important. Implications for the profitable review were suggested in the study.

• 한국대기환경학회지
• /
• 제12권2호
• /
• pp.167-177
• /
• 1996

To investigate the source-receptor relationships aerosol model has been used to simulate the distribution behavior of the yellow sand. Data for meteorological fields were obtained by Meso-scale Analysis and Prediction Model System/Seoul National University (MAPMS/SNU) for five days (10-14 April 1988). To obtain the distributions of concentration of yellow sand,the aerosol model has been modified to allow quantifications of relative concentration distributions of yellow sand. Source regions of yellow sand were delineated by soil maps of China and emission rate as a function of wind stress(Westphal et al., 1987). Using 3-dimensional wind fields the backward trajectories from 3 receptor grids at the layer of .sigma. =0.95, 0.9, 0.85, 0.8 were calculated. In order to facilitate quantitative assessment of source-receptor relationships, it was assumed that the perturbations in along-trajectory and cross-trajectory proceed linearly with time, in accord with Gaussian distribution characteristics. On the basis of this assumption, the probability fields were calculated from every grid point with source strength 1. Using these probability fields and emission retes, the potential contributions of upstream sources along the trajectories were estimated. The results of this study indicate that the application of trajectory modeling is useful in investigating the quantitative relationship between source and receptor regions.

• 공학교육연구
• /
• 제18권1호
• /
• pp.54-60
• /
• 2015

본 논문은 자기주도학습과 심층면담 프로그램이 이공계 학습부진학생의 학업성취도에 미치는 영향을 연구한 것이다. 본 연구는 학점평균 2.5미만의 학생들 17명의 신청을 받아 진행하였으며, 15주 동안의 자기주도학습 프로그램 참여와 3차의 심층면담 결과, 평균 평점(GPA, grade point average)의 변화를 분석하였다. 그 결과 참여 과목의 학업성취도, 평균 평점(GPA, grade point average)이 높아지는 효과가 있었으며, 학습 필요성에 대한 인식이 긍정적으로 변화한 것을 확인할 수 있었다.

• 대한화학회지
• /
• 제40권5호
• /
• pp.308-316
• /
• 1996

Impedance Spectroscopy를 통하여 조밀한 표면조직을 갖는 glassy carbon과 PVDF 합성흑연의 표면에 대한 전기화학적 거동을 조사하였다. 이들 두 탄소재료는 모두 전압에 대한 높은 Faraday-임피던스의존성이 나타났으며, 이를 평가하기 위한 등가회로는 PVDF 흑연의 경우 lassy carbon의 등가회로에 소수성 결합제에 의한 저항과 축전용량이 추가된 형태로 나타났다. 또한 디들 재료는 표면의 차이로 인한 전기화학적 거동의 차이도 나타났다.

• 한국초등과학교육학회지:초등과학교육
• /
• 제31권1호
• /
• pp.57-70
• /
• 2012

We investigated the perception and preferred type of question and analyzed type of questions asked by teachers in elementary science class to identify how teachers' perception of questioning is reflected in teaching practices. We collected the data from questionnaires, deep-interview and audiotaped four classes from grade 3 and six classes from grade 6. The data form deep-interview were analyzed interpretively and Blosser' framework of question was used to analyze questions which teachers used in classes. By interpretation of data from questionnaires, the teachers agreed that questioning affects science class in elementary school. There were a little differences in perceptions of questioning among three teachers. They preferred various types of question rather than a specific type. They didn't have a good understanding of questioning. The result showed that the teachers used frequently cognitive-memory question and convergent thinking question, which belonged to closed questions in their science classes. This didn't accord with their preferred types of question. The causes came from objectives of science instruction, degree of understanding about questioning, preference and confidence for science class. From this findings, we suggested that teachers should be given opportunities to take training courses in questioning in order to use effective questioning in science class.

• The Korean Journal of Physiology and Pharmacology
• /
• 제3권2호
• /
• pp.165-174
• /
• 1999

We explore the question of whether adenosine 5'-triphosphate (ATP) acts as an excitatory neurotransmitter in guinea-pig gastric smooth muscle. In an organ bath system, isometric force of the circular smooth muscle of guinea-pig gastric antrum was measured in the presence of atropine and guanethidine. Under electrical field stimulation (EFS) at high frequencies (＞20 Hz), NO-mediated relaxation during EFS was followed by a strong contraction after the cessation of EFS (a 'rebound-contraction'). Exogenous ATP mimicked the rebound-contraction. A known $P_{2Y}-purinoceptor$ antagonist, reactive blue 2 (RB-2), blocked the rebound-contraction while selective desensitization of $P_{2Y}-purinoceptor$ with ${\alpha},{\beta}-MeATP$ did not affect it. ATP and 2-MeSATP induced smooth muscle contraction, which was effectively blocked by RB-2 and suramin, a nonselective $P_2-purinoceptor$ antagonist. Particularly, in the presence of RB-2, exogenous ATP and 2-MeSATP inhibited spontaneous phasic contractions, suggesting the existence of different populations of purinoceptors. Both the rebound-contraction and the agonist-induced contraction were not inhibited by indomethacin. The rank orders of agonists' potency were 2-MeSATP > ATP ${ge}$ UTP for contraction and ${\alpha},{\beta}-MeATP\;{\ge}\;{\beta},{\gamma}-MeATP$ for inhibition of the phasic contraction, that accord with the commonly accepted rank order of the classical $P_{2Y}-purinoceptor$ subtypes. Electrical activities of smooth muscles were only slightly influenced by ATP and 2-MeSATP, whereas ${\alpha},{\beta}-MeATP$ attenuated slow waves with membrane hyperpolarization. From the above results, it is suggested that ATP acts as an excitatory neurotransmitter, which mediates the rebound-contraction via $P_{2Y}-purinoceptor$ in guinea-pig gastric antrum.

• 지질공학
• /
• 제28권2호
• /
• pp.183-192
• /
• 2018

대수층에 이산화탄소를 주입하여 저장하는 것은 대기 중 이산화탄소 농도를 저감하는데 중요한 역할을 한다. 하지만 이산화탄소 주입 시 대수층의 압력증가로 단층 재활성화가 발생할 수 있다. 이러한 문제를 예방하기위해 이산화탄소 주입에 따른 대수층 압력변화를 분석하는 것이 필요하다. 본 연구에서는 포항영일만 지질모델의 이산화탄소 주입정에서 450 m 떨어진 EF1 단층과 530 m 떨어진 EF2 단층에 대해 안정성 분석을 수행하였다. 약 2년 동안 이산화탄소의 주입과 중단을 반복하는 두 가지 시나리오에서 대수층 압력변화가 단층에 영향을 주는지 일일주입량(20 tons, 40 tons, 100 tons)에 따라 분석하였다. 또한 각 일일주입량 별로 계획 주입량과 예측 주입량을 비교하였다. 이산화탄소 일일주입량이 20 tons인 경우 단층에서의 최대압력이 단충 재활성압의 65% 수준으로 단층의 재활성화 가능성이 낮았다. 일일주입량이 40 tons과 100 tons으로 증가해도 단층에서의 최대 압력이 단층 재활성압의 각각 71%와 80% 정도이다. 또한 일일주입량이 20 tons인 경우와 40 tons인 경우 계획 주입량과 예측 주입량이 거의 일치하였지만 100 tons인 경우 주입정의 공저압력 허용한계로 인해 시뮬레이션 예측 주입량이 계획 주입량에 미치지 못하였다.