• 제어로봇시스템학회논문지
• /
• 제8권5호
• /
• pp.363-372
• /
• 2002

In ship operation, the roll motions can seriously degrade the performance of mechanical and personnel effectiveness. So many studies for the roll stabilization system design have been performed and good results have been achieved. In many studies, the stabilizing fins are used. Recently rudders, which have been extensively modified, have been used exclusively to stabilize the roll. But, in the roll stabilization control system, the control performance is very sensitive to the ship speed. So, we can see that it is important to consider the ship speed in the rudder roll control system design. The gain-scheduling control technique is very useful in the control problem incorporating time varying parameters which can be measured in real time. Based on this fact, in this paper we examine the;$H_{\infty}$-Gain Scheduling control design technique. Therefore, we assume that a parameter, the ship speed which can be estimated in real time, is varying and apply the gain-scheduling control technique to design the course keeping and anti-rolling control system far a ship. In this control system, the controller dynamics is adjusted in real-time according to time-varying plant parameters. The simulation result shows that the proposed control strategy is shown to be useful for cases when the ship speed is varying and robust to disturbances like wind and wave.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제10권1호
• /
• pp.107-119
• /
• 2006

인터넷과 웹 기술 발전에 따라 데이터베이스에 축적되는 자료의 양이 급속히 늘어나고 있다. 데이터베이스의 응용 범위가 확대되고 대용량 데이터베이스로부터 유용한 지식을 발견하고자 하는 데이터 마이닝(Data Mining) 기술에 대한 연구가 활발하게 진행되고 있다. 기존의 알고리즘들은 대부분 후보 항목 집합들을 줄임과 동시에 데이터베이스의 크기를 줄이는 방법으로 발전해 오고 있다. 그러나 후보 항목집합들을 줄이는 노력이나 데이터베이스의 크기를 줄이는 방법들이 빈발 항목집합들을 생성하는 전 과정에서 필요로 하지는 않는다. 그러한 방법들이 어느 과정에서는 시간을 줄이는데 효과가 있지만 다른 과정에서는 오히려 그러한 방법들을 적용하는데 더 많은 시간이 소요되기 때문이다. 본 논문에서는 트랜잭션들의 길이가 짧거나 데이터베이스를 이루는 항목들의 수가 비교적 적은 트랜잭션 데이터베이스에서 해슁 기법을 사용하여 데이터베이스를 한 번 스캔하고 동시에 각 트랜잭션에서 발생 가능한 모든 부분집합들을 해쉬 테이블에 저장함으로써 최소 지지도에 영향을 받지 않고 기존의 알고리즘보다 더 짧은 시간에 빈발항목집합을 발견할 수 있는 효과적인 연관 규칙 탐사 알고리즘을 제안하고 실험하였다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
• /
• pp.862-865
• /
• 1989

The authors, in this paper, investigate the degree of tracking (i.e. the weak points of Samson) to this discrete-time adaptive control system. A matter of course, the results of tracking is improved by using g given in 2.2, compared with the results of Samson. But it is a neck point that the calculation on g is very complex. So by giving the value of g suitably, it is shown that the result superior to one of Samson are taken.

• 한국환경보건학회:학술대회논문집
• /
• 한국환경보건학회 2004년도 International Conference Global Environmental Problems and their Health Consequences
• /
• pp.223-226
• /
• 2004

Building materials emit high concentration volatile organic compounds(VOCs), formaldehyde(HCHO) and other hazardous air pollutants(HAPs) to indoor environment. Average value of VOCs and HCHO emission concentration were $3,770\;{\mu}g/m^3$, $430\;{\mu}g/m^3$ in newly buildings, respectively. VOCs and HCHO emission characteristic are high emission level at initial time and decreased in course of time.

• Journal of Chest Surgery
• /
• 제21권4호
• /
• pp.778-781
• /
• 1988

With the advent of widespread mechanization and high-speed era, the incidence of traumatic rupture of the tracheobronchial tree has been increased considerably. Rupture of the bronchus is an unusual result of nonpenetrating trauma to the chest. This case was a 30 years old male who was a worker in the mine. The patient had sustained a compression chest injury with multiple rib fracture. At the time trauma, he was suffered from dyspnea, hemoptysis and hemopnemothorax of both side were noted. After tracheostomy, corrective surgery was performed with end-to-end anastomosis on the 8th time after trauma. Postoperative course was uneventful and good result of bronchogram with hypaque on the 16th day after operation.

• 한국수학사학회지
• /
• 제31권1호
• /
• pp.19-35
• /
• 2018

Taylor's Theorem is an important theorem which is applied to several disciplines. It is usually taught in a college-level calculus course for the first time. Many students have a hard time to understand or to make applications. In this paper, we look into the history of the development of Taylor's theorem and consider a teaching strategy of the theorem.

• Journal of Information Technology Applications and Management
• /
• 제14권3호
• /
• pp.227-236
• /
• 2007

Students in cyber universities can take every course because there are no physical constraints such as class rooms. On the other hand. cyber universities should take a heavy burden to schedule real-time exams in a designated time period. Any two courses a student takes must not be simultaneously allocated to a time slot in such a schedule. It is well known that the complexity of this kind of scheduling problem increases exponentially as the number of courses does. This research provides a heuristic method to make on-line real-time exam timetables with minimal exam time span. It considers the constraint of not allocating courses a student takes to simultaneous exam time and prioritizes courses by the number of students.

• 대한의료기공학회지
• /
• 제15권1호
• /
• pp.1-22
• /
• 2015

Objectives : The purpose of this study is to develop a Gi-Gong method instruction configured with modern motions to suit the Medical curing characteristics of Korean Medicine and improve the development and validation of educational and clinical needs. Methods : We took survey on 33 students after giving 'Yang-Seng Gi-Gong' lectures at Woosuk University School of Korean Medicine in the first semester of the year 2015. Results : 1. Reflection of training goal was 7.75±1.79, which showed that the education was overall interesting, but showed a high satisfaction with the practical rather than the theoretical lectures. 2. General difficulty level was intermediate, but the practice of Hwal-In-Shim-Bang Do-In-Beop from several formulations were evaluated relatively difficult exercise. 3. The propriety of training materials were rated as mostly adequate, but that assessment was relatively less appropriate for the linkage of theory and practice, and that of time allocation and place was a normal level. 4. For the propriety of time distribution, the class of one semester such as the current is rated appropriate by 61% of students. 5. General class participation was 6.34±2.52, then participation in practice than theory lessons were active. On the other hand, Induction training participation and participation appeared to be relatively low correlation, but overall interesting and participation in practice high correlation. Conclusions : The difficulty level of theory lessons is necessary to be adjusted and lecture form will need to continue focusing on practical lessons.

• 디지털융복합연구
• /
• 제10권5호
• /
• pp.1-6
• /
• 2012

본 연구는 급변하는 유비쿼터스 환경에 발맞추어 스마트의 발달과 시장의 확대로 수많은 교육용 앱이 쏟아져 나오고 있다. 학교 수업 내용에 대한 앱은 전무한 현실에서 교수자가 직접 앱을 개발하여 학교 수업에서 활용하는 방안을 연구하고자 한다. 스마트폰의 최대 장점인 시간과 장소에 구애 받지 않고, 언제 어디서나 학교 수업 내용을 학습하고 교수자와 학습자 간의 커뮤니케이션이 원활히 이루어지는 학습 환경을 만드는데 있다. 또한 앱을 외주 업체나 프로그래머에게 의뢰하지 않고 컴퓨터 비 전공자도 개발 가능한 저작도구를 이용하여 쉽고 빠르게 앱을 제작한다면 교육 현장에서 수정 및 업데이트가 용이하고 시간과 비용 낭비를 줄임은 물론 학습자의 학습 능률과 학습 효과를 최대한으로 높이고자 한다.

• Journal of the Korean Wood Science and Technology
• /
• 제4권1호
• /
• pp.48-53
• /
• 1976

This Study was carried out to investigate the course of air-drying and drying defects of red pine (Pinus densiflora S. et Z.) and Italian poplar (Populus eurameriana I-476) boards 1,2 and 3cm thick in the flat pile. The results are as follows. 1. Air-drying curves for red pine and Italian poplar boards were same as figure 1 and 2. These moisture contents were lower in July and August during seasoning periods. 2. Air drying time of red pine board required to dry 15 percent moisture content in one week for 1 cm board, five weeks for 2 cm board and six weeks for 3cm board respectively. In case of Italian poplar boards, in one week for 1 cm board, four weeks for 2 cm and five weeks for 3 cm board. The thickness of board influenced the time for air drying. 3. Drying defects such as checking, warping and staining happened badly in pine than in Italian poplar boards. Especially, checking was severe in thicker board and warping in thinner board.