• 한국학교수학회논문집
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• 제16권1호
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• pp.113-139
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• 2013

본 연구는 초등학생들의 문장제 해결과정에서 나타나는 오류를 분석하고 문제해결전략별 오류 유형 및 그 특징을 파악함으로써 문제해결학습의 실패 원인에 대한 정보를 제공하고 문제해결력을 향상시킬 수 있는 교수학습방안을 제안하기 위한 것이다. 문장제 해결과정에서 학생들이 선호하는 전략을 살펴보면 식 세우기와 예상과 확인, 규칙 찾기 순으로 나타났으며, 단순화하기 전략은 거의 사용하지 않고 있다. 문장제 해결과정에서 나타나는 오류 유형의 특징은 문제해결전략에 따라 차이를 보였는데, 이를테면 식 세우기의 경우, '문항 이해의 오류', '개념 원리의 오류', '풀이 과정의 오류' 순으로 나타난 반면, 그림그리기에서는 문제에서 설명하는 내용을 잘못 이해하여 그림으로 나타내는 오류를 주로 범하였고, 표 만들기의 경우 문제에서 주어진 정보를 표로 나타내는 과정에서 정보들 간의 관계를 잘못 이해하여 오류를 범하는 '문항 이해의 오류'가 많은 것으로 나타났다. 이처럼 문장제를 통한 문제해결 학습에서 학생들이 선호하는 문제해결전략을 확인함과 동시에 문제해결전략별 나타나는 오류의 특징을 확인함으로써 해결전략에 따른 오류를 예상하고 이에 대처하는 교수학습방안을 생각해볼 수 있을 것이다.

• International Journal of Railway
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• 제2권2호
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• pp.70-79
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• 2009

An optimal driving strategy of a train in a long journey on a nonsteep track has four phases: an initial power phase, a long hold speed phase, a coast phase and a final brake phase. The majority of the journey is speed holding. On a track with steep gradients, it becomes necessary to vary the strategy around steep sections of track because it is not possible to hold a constant steep on steep track. Instead we must interrupt the speed hold phase with a power phase. The aim of this paper is to show that there is a unique power phase that satisfies the necessary conditions for an optimal journey. The problem is developed and solved for various cases, from a simple single steep gradient to a complicated multiple steep gradient section. For each case, we construct a set of new conditions for optimality of the power phase that minimises the energy used during the power phase subject to a weighted time penalty. We then use the new necessary conditions to develop a calculate scheme for finding an optimal power phase for a steep incline. We also present an example to confirm the uniqueness of an optimal power phase.

• 한국멀티미디어학회논문지
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• 제19권2호
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• pp.271-279
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• 2016

The recent development of the HD (High Definition) and UHD (Ultra High Definition) technology allowed the growth of 3D contents market. Yet the majority of the 3D contents in the market are strictly for 6.5 cm inter-ocular distance, causing various visual discomforts for the viewers who have different inter-ocular distance. Moreover, because the 3D contents are created for a fixed viewing distance, the change of the viewing distances when watching 3D contents can also cause visual conflicts. To solve this problem, we devised techniques that consider the environmental information of the viewer watching 3D contents. By analyzing the relationship between viewing distance, inter-ocular distance, and perceived depth, we created an adaptive content viewing system that reflects the viewer's environment to minimize any conflicts in watching 3D contents. From our experiments, we found that the performance of our adaptive content viewing system was reasonable.

• International Journal of Advanced Culture Technology
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• 제2권2호
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• pp.19-24
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• 2014

Many people all over the world have been conducting a great deal of research to solve the problem of global warming since the great majority consider reduction of CO2 as the only solution for that. That is why the production and conservation of energy is thought to be highly crucial. while it is important to produce energy with the high efficiency, the efficient use of the energy is also important. This paper focused on the development of devices for the reducing electricity which is a primary energy source used in homes, shops, buildings, factories and so on. Also the objective of this paper is to develop the inference mechanism as the core component of the devices. Therefore, in this paper, we propose the inference algorithm for reducing the electricity consumption using SARIMA mode and present the feasibility of the procedure.

• Childhood Kidney Diseases
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• 제15권1호
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• pp.1-13
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• 2011

Hypertension is a major risk factor of atherosclerosis which results in cardiovascular disease, and remains a major health problem worldwide. While children are more likely to have secondary hypertension, recent studies support the theory that the prevalence of essential hypertension in children and adolescents is increasing with the global epidemic of childhood obesity, and close attention is needed. Evaluation of hypertension in the pediatric age group should be guided by the age at presentation, and renal diseases must be considered in every child with hypertension, because of the prevalence of renovascular and renal parenchymal disorders as the etiology in any age group. The majority of children with chronic kidney disease are hypertensive, and many have associated end organ damage. Thus, once hypertension has been confirmed, end organ care as well as pharmacologic therapy must be continued. In renovascular hypertension, as cure could be gained with surgical/endovascular intervention, accurate diagnosis is important and it is recommended that every suspected child should undergo angiography.

• The Korean Journal of Physiology and Pharmacology
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• 제17권4호
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• pp.347-357
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• 2013

Drug abuse has become a major social problem of the modern world and majority of these abusive drugs or their metabolites are excreted through the kidneys and, thus, the renal complications of these drugs are very common. Morphine, heroin, cocaine, nicotine and alcohol are the most commonly abused drugs, and their use is associated with various types of renal toxicity. The renal complications include a wide range of glomerular, interstitial and vascular diseases leading to acute or chronic renal failure. The present review discusses the renal toxicity profile and possible mechanisms of commonly abused drugs including morphine, heroin, cocaine, nicotine, caffeine and alcohol.

• International Journal of Knowledge Content Development & Technology
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• 제6권1호
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• pp.105-116
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• 2016

Use of information technology in providing efficient library services is inevitable in today's information world. Its implementation causes many challenges for all the stake holders. This study is an attempt to identify challenges faced by university libraries of Pakistan in information technology adoption. To elucidate the research problem, a combination of quantitative and qualitative research methods was used. Valid returned questionnaires (N=52) and recorded interviews of 51 LIS professionals with experience in library automation were analyzed to draw the results. The study determined that 'lack of training opportunities for LIS professionals' and 'lack of IT skills among the majority of LIS professionals' are major challenges to the adaptation of IT. Similarities were found in the results of this study and some previous studies conducted at national and international levels.

• 전자공학회논문지A
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• 제32A권10호
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• pp.19-24
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• 1995

The majority of problems to which FDTD is being applied involve open structure which require the appropriate scheme to terminate the computational domain. In particular, for the propagation problem of the outgoing waves, a certain type of boundary condition needs to be applied on outer boundaries of the computational domain to generate no reflected waves. In this paper, a new simple technique is presented, which allows the reduced computation time and excellent absorbing characteristics for normal and oblique incident waves on outer boundaries. To illustrate the validity of this method, a numerical calculation for monopole antenna is carried out and the results are compared to measured data. The time-domain properties for circular patch antennas are investicated.

• 산업기술연구
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• 제24권B호
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• pp.73-81
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• 2004

The development of efficient and precise handling of an liquid crystal display (LCD) panel has been addressed as the sizes of LCD panels become much larger than ever. The majority part of LCD panel handling is conducted by industrial robots for the cost reduction and the quality control. A challenging problem, vibration of the panel, can be found when the robots are utilized for handling LCD panels. The vibration causes the poor product precision and the low productivity. The characteristics of LCD panels, which are the high size-to thickness ratio, the high elasticity, and the high brittleness, are the major sources of the vibration This paper introduces the vibration attenuation techniques to overcome the difficulties encountered in the LCD production using the industrial robots.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.426-431
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• 1997

Features are well recognized to play an important role for the integration of ACD and CAPP. Majority of pervious works for the feature recognition for prismatic part is based on 3D solid model. But in real factories, 2D drawing are used more than 3D drawings. In this paper, we develope an algorithm of the feature recognition on prismatic parts in 2D drawings, using by the graph method and the heuristic algorithm. Previous algorithms have some conflicts at feature interaction. In this paper, elements are grouped into connection by the graph method. Then features are recognized by using these grouped elements and their relationships of front and side-view. For resolving the problem of feature interaction, the element graphs are modified by an deloped algorithm. This algorithm is applied to a CAPP system for milling process planning.