• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.34-34
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• 2003

목적 : 폐암 환자 세기변조방사선치료 과정을 소개하고, 방사선치료계획의 최적화를 위한 빔 수와 방향, 가상장기 설정 (virtual organ delineation, VOD) 및 선량 제한 인자들의 이용에 대해 평가함으로써 폐, 심장 등에 조사되는 선량을 최소화하는데 사용하는 세기변조방사선치료 (intensity modulated radiotherapy, IMRT) 기술의 유용성을 평가하고자한다. 대상 및 방법 : 종양이 종격동을 침범하여 상대적으로 장기움직임에 의한 오차가 적은 폐암환자 5 명을 대상으로 하였다. 환자고정장치는 상반신을 편안하게 유지함과 동시에 팔의 위치를 고정시킴으로써 기대할 수 있는 환자고정효과와 벨트를 이용하여 환자 상복부를 압박해줌으로써 호흡운동에 의한 장기 움직임을 감소시킬 수 있는 형태로 고안하였다. 치료계획시 빔 수와 방향은 5,7,9 문 (from 200 to 160, equispaced field, arbitrary field), 4 문 (anterior, posterior, bilateral posterior oblique field) 과 비등방 7, 9 문 (non-equispaced field, arbitrary field) 등을 사용하였다. 선량제한 ($V_{20}V_{25}$)은 문헌에 기초하여 설정하였으며, 가상장기를 적절히 사용하여 최적화된 치료계획 결과를 얻었다. 방사선치료계획 평가는 선량-체적간 히스토그람 (DVH), 등선량곡선 및 선량통계 등을 이용하여 수행하였다. 특히 가상장기 설정 전, 후의 결과 값을 분석함으로써 그 유용성을 확인하였다. 결과 : 9문 등방-IMRT와 7문 비등방-IMRT 방법이 치료계획용적의 선량균질성 (PTV dose homogeneity), 평균 폐선량 (mean lung dose) 및 $V_{20}V_{25}$ 모두에서 20% 이내의 좋은 결과를 얻을 수 있었고, 가상 장기를 설정함으로써 같은 결과를 가져옴을 알 수 있었다. 또한 폐암 세기변조방사선치료 프로토콜을 작성하여 임상에 사용함으로써 치료과정 중 발생할 수 있는 오류를 보완할 수 있음을 알 수 있었다. 결론 : 폐암 세기변조방사선치료 시 사용할 수 있는 프로토콜을 작성하였고, 적절한 가상 장기 및 조사계획 설정으로 치료계획의 최적화를 얻을 수 있음을 알 수 있었다.

• Journal of the Korean Society of Costume
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• v.58 no.2
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• pp.134-148
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• 2008

Methods of delivering products to consumers do not act as less important factor than creative activities to create new product designs. Mobilizing various psychological elements based on human instinct and desire, fashion industry presents a product as an object of envy, gaining viewers' attention. Here, the viewer does not simply take the product as an object to view, but also imagine transformation it will bring. The study of the cause and effects of the interaction, which is found in the relationship between "the viewer" and "what is viewed" is an important factor that needs to be identified in the phase of creation as well as in the aspect of delivery. The relationship between the perceiver and what is perceived features in designs, product advertisements, related articles, and fashion shows in modern fashion, serving as a medium that enables the humans, who must inevitably exist between the two poles such as mind and body, the subject and the object, the ego and non-ego, and the reality and an ideal, to communicate between the poles. Humans cannot do arbitrary acts or make arbitrary selections only as they access to foreign things through instinct, desire, or experienced perception, and they are sometimes positioned passive by things. In the background, as there are human dual characteristics in which they are expressed as the ego and another ego who exists inside of the ego, they not only view an object, but also become an object to be viewed. Many products in modern fashion, as the objects of reciprocal transposition, grow giving illusions to humans. Having a desire for such objects is human's instinct and normal act to keep the life balanced between the reality and an ideal, which is based on the activation of reality function. Furthermore, freely acting rather than ignoring or overcoming the desire may be the act of retrieving one's ownership to the ego.

• Structural Engineering and Mechanics
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• v.48 no.6
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• pp.775-789
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• 2013

The current paper proposes a boundary element formulation, applicable to 2-D and 3-D elastostatics problems using a unified approach for transformations of the domain integrals into boundary integrals. The method is applicable to linear problems encompassing both finite and infinite multi-region domains allowing non-vanishing body forces. Numerical results agree quite well with the analytical solutions; while the present method offers easy formulation with less numerical efforts in comparison to FEM or some BEM which need interior points to treat arbitrary body forces. It is demonstrated that the method has the potential to have profound impact on engineering design, notably in dam-foundation interaction.

• Journal of the Korean Society of Safety
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• v.28 no.6
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• pp.57-63
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• 2013

This paper discusses 2D models of beams for simulating the fracture of brittle materials. A simulation of an experiment on a concrete beam subjected to bending, in which two overlapping cracks occur, is used to study the effect of individual beam characteristics and different arrangements of the beams in the overall network mesh. It was found that any regular orientation of the beams influences the resulting crack patterns. Methods to implement a wide range of poisson's ratios are also developed, the use of the mesh to study arbitrary micro-structures is outlined. The crack pattern that are obtained with mesh are in good agreement with the experimental results. Also, numerical simulations of the tests were performed by means of a model, and non-integer dimensions were measured on the predicted mesh damage patterns.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.536-539
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• 2004

In this paper, a brief discussion on I-PD position controller design for step motor drive is presented. The proposed method mainly focuses on the robustness property of the controller, which is very important for this type of system in which the variation of external load affects plant parameters. It is considered in this paper that two types of controller design methods namely; Coefficient Diagram Method (CDM), and arbitrary Pole Assignment Method (PAM) are treated and compared them. The control plant chosen for our study is a SM inherently is comprised of some non-linear elements. A the scope of the design method is limited to only linear time invariant systems, the SM modeling is approximated to linear system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.463-469
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• 2004

This paper discusses 2D lattice models of beams for simulating the fracture of brittle materials. A simulation of an experiment on a connote beam subjected to bending, in which two overlapping cracks occur, is used to study the effect of individual beam characteristics and different arrangements of the beams in the overall lattice. It was found that my regular orientation of the beams influences the resulting crack patterns. Methods to implement a wide range of poisson's ratios are also developed, the use of the lattice to study arbitrary micro-structures is outlined The crack pattern that n obtained with lattice m in good agreement with the experimental results. Also, numerical simulations of the tests were performed by means of a lattice model, and non-integer dimensions were measured on the predicted lattice damage patterns.

• Journal of Forest and Environmental Science
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• v.24 no.2
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• pp.61-68
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• 2008

Acrylamide is present as a contaminant in heated food products, predominantly from the precursor asparagine. Nonanchored inter simple sequence repeats (ISSRs) are arbitrary multiloci markers produced by PCR amplification with a microsatellite primer. In order to assess the feasibility of microsatellite primers as markers for DNA damage, the study was conducted on common bean (Phaseolus vulgaris L.) exposed to different concentrations of acrylamide. Polymorphisms were abundant among plant samples treated with acrylamide in comparison to control (untreated one) tested with 4- tri-nucleotide, 2 tetra-nucleotide, and 3- dinucelotide primers. The primer (CCG)4 was the best tested primer to generate polymorphism between the DNA of plants treated or not by acrylamide. Polymorphisms became evident as the presence and absence of DNA fragments in treated samples compared with the untreated one. The highest number of DNA variation on ISSR patterns was observed at the micromollar concentrations of acrylamide. Acrylamide was able to induce DNA damage in non concentration-dependent manner with effectiveness at micromollar concentrations. This study demonstrated that ISSR markers can be highly reliable for identification of DNA damage induced by acrylamide.

• Journal of Sensor Science and Technology
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• v.26 no.1
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• pp.1-6
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• 2017

The advanced driver assistant system (ADAS) requires the collection of a large amount of information including road conditions, environment, vehicle status, condition of the driver, and other useful data. In this regard, large-scale sensor networks can be an appropriate solution since they have been designed for this purpose. Recent advances in sensor network technology have enabled the management and monitoring of large-scale tasks such as the monitoring of road surface temperature on a highway. In this paper, we consider the estimation and fusion problems of the large-scale sensor networks used in the ADAS. Hierarchical fusion architecture is proposed for an arbitrary topology of the large-scale sensor network. A robust cluster estimator is proposed to achieve robustness of the network against outliers or failure of sensors. Lastly, a robust hierarchical data fusion scheme is proposed for the communication channel between the clusters and fusion center, considering the non-Gaussian channel noise, which is typical in communication systems.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.9
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• pp.2373-2380
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• 1993

This paper addresses the design procedure and testing result of a servo driven pan/tilt device which is capable of tracking arbitrary movement of a specified target object. In order to achieve real-time acquisition of feedback signal, a 2 degree-of freedom non-contact type displacement follower has been employed in stead of vision camera. The performance of the designed system is tested for different target velocities and control gains. The test result shows the satisfactory performance to be adopted as an effective tool for visual transfer in the context of teleoperation.

• Journal of Korean Institute of Industrial Engineers
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• v.3 no.2
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• pp.83-91
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• 1977

This paper investigates the reliability characteristics of a system consisting of a unit operating on-line and backed by n spares among which m units are kept "warm" as standbys ready to go on-line. The on-line unit has an arbitrary lifetime distribution, while the warm standbys have exponential failure time distributions. The Failed units are repaired and brought back to service. The cold spares do not fail while in storage. Solution of this extremely complicated queuing problem using a "renewal counting" approach is presented and extended to the situation where the warming-up takes non-negligible time. Finally, an approach to the economic system management is discussed, considering the long-run availability, cost of keeping spares and repair facility, and the associated cost of restarting the system, after a system failure. The model presented in this paper will have many applications including the determination of the spares inventory and the number of field spares to be "carried".