• 한국초전도ㆍ저온공학회논문지
• /
• 제19권2호
• /
• pp.38-43
• /
• 2017

The role of current lead in high-temperature superconducting synchronous machine (HTSSM) is to function as a power supply by connecting the power supply unit at room temperature with the HTS field coils at cryogenic temperature. Such physical and electrical connection causes conduction and Joule-heating losses, which are major thermal losses of HTSSM rotors. To ensure definite stability and economic feasibility of HTS field coils, quickly and smoothly cooling down the current lead is a key design technology. Therefore, in this paper, we introduce a novel concept of a cooling anchor to enhance the cooling performance of a metal current lead. The technical concept of this technology is the simultaneously chilling and supporting the current lead. First, the structure of the current lead and cooling anchor were conceptually designed for field coils for a 1.5 MW-class HTSSM. Then, the effect of this installation on the thermal characteristics of HTS coils was investigated by 3D finite element analysis.

• International Journal of Aeronautical and Space Sciences
• /
• 제12권2호
• /
• pp.93-114
• /
• 2011

The current status of Canadian research on rotor-based actively controlled technologies for helicopters is reviewed in this paper. First, worldwide research in this field is overviewed to put Canadian research into context. Then, the unique hybrid control concept of Carleton University is described, along with its key element, the "stiffness control" concept. Next, the smart hybrid active rotor control system (SHARCS) projected's history and organization is presented, which aims to demonstrate the hybrid control concept in a wind tunnel test campaign. To support the activities of SHARCS, unique computational tools, novel experimental facilities and new know-how had to be developed in Canada, among them the state-of-the-art Carleton Whirl Tower facility or the ability to design and manufacture aeroelastically scaled helicopter rotors for wind tunnel testing. In the second half of the paper, details are provided on the current status of development on the three subsystems of SHARCS, i.e. that of the actively controlled tip, the actively controlled flap and the unique stiffness-control device, the active pitch link.

• 한국의사학회지
• /
• 제22권1호
• /
• pp.69-80
• /
• 2009

Complementary/alternative medicine has been developed in extremely diverse forms reflecting inter-state historical, cultural differences. As Korean Medicine is institutionally accepted to the same status of Western Medicine, the concept of complementary/alternative medicine needs to be realigned. Data-basing academic level Web Service DBpia, the trend of research in the field of complementary/alternative medicine was analyzed by focusing on 144 treatises listed in the Korean Journal. As the result, we could subgroup treatises as those of concept, category, current status, institutions, details, and miscellany. The treatises related to the answers to "What is Complementary/alternative medicine" apply to the category of 'concept' Likewise in category are listed the treatises covering range and kinds of medicine. In 'category', 'current status', the discussions about the direction of Complementary/alternative medicine pending and treatises dealing with clinical applications are covered. In 'institutions', treatises on policy-making are enlisted. In 'details', treatises applied on specific diseases were sub-grouped. Others not otherwise covered enlisted in the list of "Miscellany".

• KIEE International Transactions on Power Engineering
• /
• 제2A권3호
• /
• pp.89-94
• /
• 2002

In this paper, a protection system using a Multi-Agent concept for power distribution networks is proposed. Every digital over current relay(OCR) is developed as an agent by adding its own intelligence, self-tuning and communication ability. The main advantage of the Multi-Agent concept is that a group of agents work together to achieve a global goal which is beyond the ability of each individual agent. In order to cope with frequent changes in the network operation condition and faults, an OCR agent, suggested in this paper, is able to detect a fault or a change in the network and find its optimal parameters for protection in an autonomous manner considering information of the whole network obtained by communication between other agents. Through this kind of coordination and information exchanges, not only a local but also a global protective scheme is completed. Simulations in a simple distribution network show the effectiveness of the suggested protection system.

• 연구윤리
• /
• 제3권1호
• /
• pp.17-21
• /
• 2022

Purpose: Research ethics has social implications beyond the issues of personal morality and research integrity. In recent years, research ethics has become a more controversial topic in society. In this study, the concept of the university research ethics curriculum is defined, the current status of the research ethics curriculum is analyzed, and the direction of the university research ethics curriculum development direction is discussed. Research design, data and methodology: The concept of university research ethics education and the current status of research ethics education were examined, and the development direction of the university research ethics curriculum was explored based on the framework . Results: field education to secure university research ethics is still insufficient. In other words, only 12 universities for undergraduate programs and 37 universities for graduate programs included research ethics in their regular curriculum. Conclusions: The occurrence of research misconduct is mainly caused by not recognizing the error or not taking it seriously. In particular, university research misconduct results from a lack of understanding of research ethics, poor research education, a performance-oriented academic climate, and the absence of an institutional system for establishing research ethics.

• 한국초등과학교육학회지:초등과학교육
• /
• 제21권1호
• /
• pp.13-24
• /
• 2002

This study examined the knowledge structure constructed by children before formal instruction, and successive changes in the structural complexity of knowledge during the learning of the 'Structure and Function of Plants' unit. The researchers let the 5th graders draw the first draft of their concept maps in order to examine the pre-existing knowledge structure concerned with the unit and also four concept maps after completing every fourth lesson. Each concept map drawn by children on the basis of the previous one showed the degree of their current understanding on the structure and function of plants. The results revealed that only two levels of hierarchy and five relationships among the components of the first concept map(relationship, hierarchy, cross link and example) were proven to be valid in terms of conceptual relevance. According to the standard map, there was no change in hierarchy from the 2nd to the 3rd map, and in example from the 2nd to the 4th map. However, the gradual and successive increases of the scores in all components appeared in the children's maps throughout the unit. Knowledge restructuring occurred strongly in the early periods from the 1st to the 6th lesson, and the significant stable changes in tuning and accretion appeared throughout the whole lessons. The results also showed that there were no significant gender differences on the 5th grader's knowledge structuring.

• 정보과학회 논문지
• /
• 제44권8호
• /
• pp.842-853
• /
• 2017

스트리밍 데이터는 시간에 따라 지속적으로 생성되는 데이터 시퀀스이다. 시간이 지남에 따라 데이터의 분포 또는 컨셉이 변화할 수 있으며, 이러한 변화는 분류 모델의 성능을 저하시키는 요인이 된다. 점층적 적응적 학습 방법은 컨셉 변화의 정도에 따라 현재 분류 모델의 가중치를 조절하여 업데이트를 수행함으로써 컨셉 변화에 대한 분류 모델의 성능을 유지할 수 있게 한다. 그러나, 컨셉 변화의 정도에 맞는 적절한 가중치를 결정하기가 어렵다는 문제점이 있다. 본 논문에서는 컨셉 변화에 따른 적응적 가중치 조정에 기반한 동적 앙상블 방법을 제안한다. 실험 결과는 제안한 방법이 다른 비교 방법들에 비해 높은 성능을 보여줌을 입증한다.

• 전력전자학회논문지
• /
• 제20권3호
• /
• pp.232-238
• /
• 2015

A sensorless control algorithm of brushless DC (BLDC) motors with a model current based on 120 degree conduction mode is proposed in this paper. The rotor speed and position can be estimated using the current model of BLDC motor, which is a modified version of the conventional current model of permanent magnet synchronous motor. The rotor speed and position can be obtained using the difference of the actual current and the model current. The position error caused by the parameter errors of the model current is compensated using a PI controller and the feedback loop of the real current. The validity of the proposed sensorless control algorithm is verified through simulation.

• 한국주거학회논문집
• /
• 제13권5호
• /
• pp.1-8
• /
• 2002

Contemporary architecture shows complex aspects of various design in form and material. Such trends even change classical materiality and this concept is believed to be the background of current ideas - digital, information, imagination with paradigm. This study inquires the general concept of dematerial. In the process searching for the forming basic background this study understands the characteristic. With characteristics drawn in chapter three, this study show the present status of the architectural expressions in the contemporary house in Korea under its dematerialized situation. And like this, we know fur study about the relation between dematerialization and current architecture, still more Korean present condition.

• Clinics in Shoulder and Elbow
• /
• 제17권4호
• /
• pp.209-217
• /
• 2014

Most studies on the pathophysiology, natural history, diagnosis by imaging and outcomes after operative or nonoperative treatment of rotator cuff tear have focused on those of full-thickness tears, resulting in limited knowledge of partial-thickness rotator cuff tears. However, a partial-thickness tear of the rotator cuff is a common disorder and can be the cause of persistent pain and dysfunction of the shoulder joint in the affected patients. Recent updates in the literatures shows that the partial-thickness tears are not merely mild form of full-thickness tears. Over the last decades, an improved knowledge of pathophysiology and surgical techniques of partial-thickness tears has led to more understanding of the significance of this tear and better outcomes. In this review, we discuss the current concept of management for partial-thickness tears in terms of the pathogenesis, natural history, nonoperative treatment, and surgical outcomes associated with the commonly used repair techniques.