• Journal of Astronomy and Space Sciences
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• 제9권1호
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• pp.11-29
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• 1992

In 1963, Toomre built up classes of mass models for the highly flattened galaxies which have free parameters n, $a_n$ and $C_n$. In order to keep the universal dimension, we adopt parameters $b_n({C_n}^2={a_n}^{2n}+^2{b_n}^2/(n-1)!)$ insteal of $C_n$. Series of the normalized Toomre's mass models (G = $V_{max}$ =$R_{max}$ = 1, n = 1 to 7) are derived and the normalized parameters $a_n$ and $b_n$ are determined by the iteration method. Replacing parameters $a_n$ and $b_n$ to ${a_n}^l(=a_nr_{max})$ and ${b_n}^l(=b_n\cdotV_{max}/r_{max})$, we can get the generalization of Toomre's mass model.

• 대한조선학회논문집
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• 제45권6호
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• pp.601-610
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• 2008

This paper deals with a new geometrical surface modeling method of forebody's hull form which is fully defined by form parameters. The complex hull form in the forebody can be modeled by the combination of three parts: bare hull, bulbous bow and blending part which connects a bare hull and a bulbous bow. All these subdomain parts are characterized by each own form parameters and constructed with simple surface model. For this, we need only 2-dimensional hull form data and then the form parameters are calculated automatically from these data. Finally, the smooth hull form surfaces are generated by parametric design and fair-skinning. In the practical point of view, we show that this new method can be useful and efficient modeling tool by applying to the hull form surface modeling of Panamax container's forebody.

• 산업공학
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• 제15권3호
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• pp.256-262
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• 2002

In this paper, we develop a framework for identifying the quality of service(QoS) and network performance (NP) in the IMT-2000 services, and analyze the QoS/NP system in the 3GPP IMT-2000 services. Based on the ITU-T E.800, the QoS is classified into customer, technical, contents, telecommunications quality, and internet communication quality, and the NP consists of the service access/transmission, reliability/operating & maintenance, charging performance, and mobility management performance. Under the basic framework, the major parameters in the IMT-2000 services are identified for each QoS/NP criterion. The QoS framework in the IMT-2000 user aspects is also introduced to determine the major QoS parameters. Finally, to define the performance factors of the network elements in the NP system, the various control parameters for the wireless and core networks are presented.

• 한국식품과학회지
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• 제16권3호
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• pp.309-313
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• 1984

츄잉검의 기계적(機械的) 물성(物性)과 관능적(官能的) 물성(物性) 및 기호성(嗜好性)과의 상관관계로부터 츄잉검의 텍스쳐를 잘 표현하는 물성(物性)을 찾아내었고 대표적(代表的)인 기계적(機械的) 물성(物性)으로부터 기호성(嗜好性)을 여측(予測)하는 식(式)과 ideal texture profile을 제시하였다. 츄잉검의 텍스쳐를 가장 잘 표현(表現)하는 대표적(代表的)인 물성(物性)은 초기(初期)의 관능적(官能約) stiffness와 기계적 puncture work, 중기(中期)의 관능적(官能的) firmness와 기계적(機械的) hardness, 후기(後期)의 관능적(官能的) firmness와 기계적(機械的) hardness, slope 및 관능적(官能的) lift 와 기계적(機械約) springiness이었다. 대표적(代表的)인 기계적(機械的) 물성(物性)으로 소비자(消費者)의 기호성(嗜好性)을 다음과 같이 여측(予測)하였다. 소비자(消費者)의 종합점수(綜合点數) = $7.336-0.369{\time}10^{-5}(Puncture work)+0.075{\time}10^{-5}(Intermediate\;hardness)+0.382{\time}10^{-5}(Final hardness)-0.806{\time}10^{-5}(Slope)-5.168(Springiness)$. 시대적(代表的)인 기계적(機械約) 물성(物性)으로 ideal texture profile을 작도하였다.

• 한국수자원학회논문집
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• 제43권1호
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• pp.25-39
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• 2010

최근 들어 WMS와 ArcHydro 및 HyGIS와 같이 수문학적 지형인자를 생성할 수 있는 GIS 프로그램이 널리 보급되고 있다. 이러한 프로그램에서는 격자형 고도자료인 DEM (Digital Elevation Model)을 이용하여 수자원에서 필요로 하는 다양한 지형인자를 계산할 수 있는 기능을 제공하고 있다. 본 연구에서는 HyGIS로부터 산정된 수문학적 지형인자의 적용성을 평가하기 위해서 국내에서 주로 사용되고 있는 WMS와 ArcHydro를 이용하여 수문학적 지형인자를 산정하고 그 결과를 HyGIS의 계산 결과와 비교 검토하였다. 연구 대상유역으로는 보청천, 위천, 평창강, 경안천, 내린천, 임진강 유역을 선정하였으며, 각 유역에 대해서 추출된 유역의 형태와 함께 유역 면적, 유역 경사, 유역평균고도, 최대유하거리, 최대유하거리 경사, 주하천 길이, 주하천 경사에 대한 산정결과를 비교검토 하였다. 연구결과 전체 유역에 대한 7개의 지형인자의 평균 상대오차는 4.77 %를 나타내었으며, 각 유역에 대해서 추출된 유역 경계 또한 매우 유사하게 생성되었다. 이와 같이 각각의 프로그램은 매우 유사한 지형인자 계산 결과를 나타내고 있으며, 따라서 HyGIS에서 계산된 지형인자는 기존에 국내에서 활용되어 왔던 WMS 및 ArcHydro와 함께 수자원 분야에서 충분히 적용 가능한 것으로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.156-160
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• 1993

This paper presents a controller design to coordinate a robot manipulator under unknown system parameters and bounded disturbance inputs. To control the motion of the manipulator, an inverse dynamics control scheme is applied. Since parameters of the robot manipulators such as mass and inertia are not perfectly known, the difference between the actual and estimated parameters works as a disturbance force. To identify the unknown parameters, an inproved adaptive control algorithm is directly derived from a chosen Lyapunov's function candidate based on the Lyapunov's Second Method. A robust control algorithm is devised to counteract the bounded disturbance inputs such as contact forces and disturbing force coming from the difference between th actual and the estimated system parameters. Numerical examples are shown using three degree-of-freedom planar arm.

• 한국공작기계학회논문집
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• 제12권6호
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• pp.36-43
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• 2003

In machining of ceramic materials, they are very difficult-to cut materials because of there high strength and hardness. Machining of ceramics are characterized by cracking and brittle fracture. Generally, ceramics are machined using conventional method such as finding and polishing. However these processes are generally costly and have low MRR(material removal rate). This paper focuses on determining the optimal levels of process parameters for products with CNC machining center. For this purpose, the optimization of cutting parameters is performed based on experimental design method. A design and analysis of experiments is conducted to study the effects of these parameters on the surface roughness by using the S/N ratio, analysis of ANOVA and F-test. Cutting parameters, namely, cutting speed, feed and depth of cut are optimized with consideration of the surface roughness.

• 한국소음진동공학회논문집
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• 제26권7호
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• pp.814-819
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• 2016

The Stockbridge damper is used to control the aeolian vibration of a overhead transmission line due to the natural wind under a low velocity, between 1 m/s to 7 m/s. The damper model can be simply derived with several design parameters and the location of eigenvalues of design parameters are important to determine the efficiency of energy dissipation by excitation itself with two counterweights. First, the importance of resonance frequencies of Stockbridge damper was reviewed through the analysis of frequency response function of damper system. Then, the best selection of design parameters was investigated with the introduction of objected function that minimize the distance between the calculated eigenvalues and target frequency points. The best choice of design parameters was reviewed using the simulated results from the objective function and the effectiveness of selected design case was discussed at the point view of practical implementation.

• 한국정밀공학회지
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• 제26권6호
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• pp.122-130
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• 2009

The analysis of human movement requires the knowledge of the Hill type muscle parameters, the muscle-tendon and moment arm length change as a function of joint angles. However, values of a subject's muscle parameters are very difficult to identify. It turns out from a sensitivity analysis that the tendon slack length and maximum muscle force are the two critical parameters among the Hill-type muscle model. Therefore, it could be claimed that the variation of the tendon slack length and maximum muscle force from the Delp's reference data will change the muscle characteristics of a subject remarkably. A numeric optimization method to search these tendon parameters specific to a subject is proposed, and the accuracy of the developed algorithm is evaluated through a numerical simulation.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.6-9
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• 1996

In this paper, we attempted to analyze the contraction patterns of elbow flexor muscle during isometric, concentric and eccentric contraction. The analysis parameters are consisted of Sequency domain parameters (mean frequency, median frequency, skewness, kurtosis) and time domain parameters (zero crossing, positive maxima, integrated EMG). As a results, the analysis parameters have specific trends for muscles, muscle contraction patterns, muscle contraction angles. Especially, at the time domain analysis, IEMG is a dominant parameter for analysis of activation patterns, and the skewness, kurtosis are useful parameters for functional recognition.