• 전자공학회논문지B
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• 제32B권10호
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• pp.1259-1268
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• 1995

This note presents the robust root clustering problem of interval systems whose characteristic equation might be given as either a family of interval polynomials or a family of polytopes. Corresponding to damping ratio and robustness margin approximately, we consider a certain class of D-region such as parabola, left-hyperbola, and ellipse in complex plane. Then a simpler D-stability criteria using rational function mapping is presented and prove. Without .lambda. or .omega. sweeping calculation, the absolute criteria for robust D-stability can be determined.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.567-572
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• 1988

As an efficient way of modeling bodies of complicated shapes, the sweeping and skinning operations have been implemented. These two operations are very powerful modeling method when the body is defined by the cross sections at various locations. For the implementation, the data structure for storing the cross sections and the resulting three dimensional body has been constructed. The resulting object is defined by the boundary representation based on the non-uniform nonperiodic B-spline surface.

• 한국멀티미디어학회논문지
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• 제18권11호
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• pp.1375-1382
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• 2015

This paper aims to introduce the numerical methods for solving the optimal control theory to model bufferbloat problem. Mathematical tools are useful to provide insight for system engineers and users to understand better about what we are facing right now while experiment in a large-scale testbed can encourage us to implement in realistic scenario. In this paper, we introduce a survey of the numerical methods for solving the optimal control problem. We propose the dynamic optimization sweeping algorithm for optimal control of the active queue management. Simulation results in network simulator ns2 demonstrate that our proposed algorithm can obtain the stability faster than the others while still maintain a short queue length (≈10 packets) and low delay experience for arriving packets (0.4 seconds).

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.509-512
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• 2013

본 논문은 산업용 로봇을 위한 힘 피드백 제어는 사람의 감각을 기반으로 한 작업을 대체하여 구현하기에 적합한 연마 시스템을 제안하였다. 기존 연마작업의 표면 연마, 비드처리, 기계 가공 디버링 등의 공정은 그 복잡성에서 자동화가 가장 곤란하다고 인식되어 주로 인력에 의존 해왔다. 본 연구는 연마 공구를 파지시킨 힘 제어 로봇에 의한 자동 연마 시스템의 구축을 위한 다축로봇 기반의 힘 센서로부터 신호 피드백 제어 방식의 특성을 파악하고 연마 공정에 적응성을 검증했다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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• pp.243-246
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• 2009

Localized rainfall due to abnormal climate has caused extensive damages killing several tens to hundreds of people for yearly basis. The typhoon 'Lusa' of year 2002 has resulted 5,400 billion won of property damage and the damages for roads were approximated to be 2,860 billion won at 12,377 locations holding 53% damage of total. The recent typhoon, 'Aewinia' of yeat 2006 caused the 1,400 billion-won property damage including sweeping and flooding of 127 roads and 65 rivers, respectively. There are needs to minimize the damages for important structures for repeated heavy rainfalls every year and, especially, because debris flow might be a main cause of road damage, the design criteria and guideline for roads are required to be improved. Therefore, this paper presented design method of debris-flow control structure for road protection.

• 생태와환경
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• 제49권4호
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• pp.271-278
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• 2016

Forest clear-cutting operations influence biodiversity through habitat changes and food resource availability for inhabitant species. This study examined the effects of clear-cutting on forest arthropod communities. Arthropods were collected from two different forest treatment areas (clear-cut and control) in summer and autumn. In each treatment area, arthropods were sampled from both crown and ground surfaces using sweeping and pitfall trap methods, respectively. Then, the taxonomic order of the collected arthropod specimens was easily identified. Results indicate that arthropod abundance and number of taxa present were higher at ground surface than at crown levels in both clear-cut and control areas. At crown level, more homopteran species were present in clear-cut areas than in control areas in summer. At ground surface, populations of Isopoda and Opiliones were higher in control areas than in clear-cut areas, whereas numbers of Araneae, Orthoptera, and Hymenoptera were greater in clear-cut areas. Cluster analysis and principal component analysis showed distinct differences between clear-cut and control communities at crown level in summer and at ground surface in autumn. Thus, our results indicate that clear-cutting significantly influences arthropod communities, and higher taxa are valuable for conducting rapid biological assessments of ecosystem disturbances.

• Toxicological Research
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• 제27권3호
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• pp.149-152
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• 2011

We describe here a multicentric spontaneous malignant schwannoma obtained from one male F344 rat, and this animal was the subject of a carcinogenicity study for which it was treated with diisodecyl phthalate. The animal of the control group not treated with diisodecyl phthalate showed dyspnea and severe lordosis. On the necropsy, two tan, firm, encapsulated masses were observed in the subcutis of the lumbosacral region and the left inguinal region of the abdominal cavity, respectively; the masses were $25{\times}17{\times}8$ mm and $16{\times}14{\times}8$ mm in size, respectively. Histologically, the tumor consisted of spindle and pleomorphic cells that grew in various patterns, that was, sweeping fascicles and herringbone and local organoid patterns. The pleomorphic neoplastic cells had more than two nuclei. Additionally, the diagnosis of malignant schwannoma was confirmed by the immune reactivity of the tumor cells for S-100 protein.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.926-931
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• 2008

In order to design a high-performance controller with excellent positioning and tracking performance, an optimal tuning method based on the integrated design concept is studied. DOBs, feedforward controllers and CCC are applied to control the bi-axial linear servomechanism. To derive accurate dynamic models of mechanical subsystems equipped with linear servos for the integrated tuning, system identification processes are conducted through the sine sweeping. An optimal tuning problem with stability, robustness and overshoot constraints is formulated as a nonlinear constrained optimization problem. Optimal gains are obtained through the SQP method. Experimental results confirm that both tracking and contouring errors are significantly reduced by applying the proposed controller and integrated tuning method.

• 한국정보과학회논문지:소프트웨어및응용
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• 제36권11호
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• pp.947-954
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• 2009

본 논문은 입력받은 다수 이미지의 Visual Hull을 이용하여 Surfel 기반의 물체를 복원하는 새로운 방법을 제안한다. Sufel은 포인트 집합면을 효과적으로 근사하여 나타내는 포인트 표현 단위이다. LDC(Layered Depth Cube) Surfel 샘플링 방식에 입력 이미지로부터 근사되는 형상을 대표하는 Visual Hull의 개념을 연동하여 이미지로부터 물체의 Surfel 기하 정보를 생성할 수 있다. Surfel 표현 방식은 기존의 폴리곤 기반 방식에 비해 상대적으로 적은 메모리를 소모하고 LDC 해상도를 자유롭게 바꿀 수 있기 때문에, 대상 물체를 복원하는 품질을 조절 가능하며, 주어진 메모리 자원에 대해서 최대의 품질을 가진 결과를 얻을 수 있다.

• 환경생물
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• 제23권2호
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• pp.129-134
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• 2005

포란한 성충 암컷 Tigriopus japonicus(요각류)를 내분비계 교란물질로 잘 알려져 있는 4-nonylphenol에 노출하여 생존율과 포란율의 변화를 살펴보았다. 실험생물은 2004년 4월 제주도 구안연안에서 플랑크톤망으로 쓸어 잡기로 채집한 후 실내순응을 한 달 동안 시켰다 치사율은 노출농도의 높아지면 증가하였으나 그 경향이 뚜렷하지 않았다. 반면, 노출 후 처음으로 치사한 개체가 발생하는 시기는 비처리군과 처리군에 따라 명백한 차이를 보였다. 포란한 암컷을 실험조건에 이동시키면 생리적인 변동으로 인해 알이 떨어졌다가 $4\~5$일 후 비처리군은 $100\%$ 포란을 회복하지만 처리 군에서는 $89\~95\%$가 회복되어 약제노출에 따른 영향을 보였다. 치사가 발생하는 시기는 비처리 시에는 10일 후부터이지만 노출 시에는 4에서 6일 후부터 발생하였다.