• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 춘계학술대회
• /
• pp.68-71
• /
• 1997

The early detection of brest cancer is clearly a key ingredient for any strategy designed to reduce breast cancer mortality. Microcalcification(MCC) is one of the primary signatures to discriminate between normal and cancerous tissue. The detection and locating procedures can be automated by digital image processing, however, MCCs have various sizes, shapes, and intensity levels in film images, so it is difficult to find accurate locations and sizes. Firstly, we made quantitative analysis for many characteristic features of mammograms that can be used to segment MCCs from normal tissues. Secondly, we developed algorithms proper to segmentation like pattern matching. The performance was evaluated with TP and FP rates.

• 전자공학회논문지A
• /
• 제31A권7호
• /
• pp.55-62
• /
• 1994

Interpattern association (IPA) model which the interconnection weight matrix(IWM) is constructed by the association between patterns is effective in similar pattern recognitions. But, if the number of reference patterns is increased, the ability of recognition is decreased. Using a hierarchical recognition algorithm which adopts the tree search strategy, we classified reference patterns into sub-groups by similarity. In IPA model, if input includes random noise we make it converge to reference pattern by means of input includes random noise we make it converge to reference pattern by means of increasing the number of pixels of prohibited state in IWM. In relation to reference patterns the pixel of prohibited state made partially prohibited state of no connected state using which is not included common and feature regions by each reference patterns.

• 한국과학교육학회지
• /
• 제31권8호
• /
• pp.1145-1157
• /
• 2011

본 연구의 목적은 초등 과학영재 수업에서 나타나는 언어적 상호작용의 특징을 살펴보고 현장에서 언어적 상호작용 전략을 수립하는데 도움을 주고자 하는 것이다. 이를 위해 지역 교육지원청 영재교육원 수업 3곳의 총 27차시 수업에 참여하여 녹화하였으며, 전사 및 코딩의 과정을 거쳐 분석하였다. 분석에 사용된 분석틀은 Sinclair와 Coulthard(1975)의 이론에 근거한 정민수 등(2007)의 분석틀에서 교사 피드백 부분을 김영순(2010)의 분석틀로 일부 수정한 언어적 상호작용 분석틀이었다. 분석 후 분석결과 확인 및 언어적 상호작용에 대한 인식을 알아보고자 수업자와의 설문조사를 실시하였다. 연구 결과, 초등 과학영재 수업에서 가장 많이 나타난 IRF 패턴 유형은 관리적 질문-단답형 응답 유형이었다. 이러한 결과의 원인을 수업 외적인 측면으로 인식하고 있었다. 또한 수업 사례를 통해 과학영재의 창의적 사고를 이끌어 내는데 효과적인 몇 가지 패턴 유형을 확인하였는데, 이를 통하여 언어적 상호작용 전략은 막연히 개방적 질문, 지연적 피드백을 따로 구분하여 각각 좋다는 인식보다 학습 내용의 난이도 및 학생의 수준 등을 고려하여 상황에 적합한 패턴 전략으로 적용되어야 한다는 것을 알 수 있었다. 교사 3명은 평소 초등 과학영재 수업에서의 언어적 상호작용 전략에 대하여 막연히 편안한 분위기, 개방적 질문과 지연적 피드백 정도로 인식하거나 전략이 아예 없는 것으로 나타났다. 앞으로 초등과학영재 담당 교사들의 언어적 상호작용 전략에 대한 연수 등 다양한 전문성 향상 기회가 마련되어야할 것으로 사료된다.

• Wind and Structures
• /
• 제18권2호
• /
• pp.195-213
• /
• 2014

Recently, the horizontal axis rotor performance optimizer (HARP_Opt) tool was developed in the National Renewable Energy Laboratory, USA. This innovative tool is becoming more popular in the wind turbine industry and in the field of academic research. HARP_Optwas developed on the basis of two fundamental modules, namely, WT_Perf, a performance evaluator computer code using the blade element momentum theory; and a genetic algorithm module, which is used as an optimizer. A pattern search algorithm was more recently incorporated to enhance the optimization capability, especially the calculation time and consistency of the solutions. The blade optimization is an aspect that is highly dependent on experience and requires significant consideration on rotor control strategies, wind data, and generator type. In this study, the effects of rotor control strategies including fixed speed and fixed pitch, variable speed and fixed pitch, fixed speed and variable pitch, and variable speed and variable pitch algorithms on optimal blade shapes and rotor performance are investigated using optimized blade designs. The effects of environmental wind data and the objective functions used for optimization are also quantitatively evaluated using the HARP_Opt tool. Performance indices such as annual energy production, thrust, torque, and roof-flap moment forces are compared.

• 대한의용생체공학회:의공학회지
• /
• 제26권4호
• /
• pp.243-249
• /
• 2005

The number of people who have lost limbs due to amputation has increased due to various accidents and diseases. Numerous attempts have been made to provide these people with prosthetic devices. These devices are often controlled using myoelectric signals. Although the success of fitting myoelectric signals (EMG) for single device control is apparent, extension of this control to more than one device has been difficult. The lack of success can be attributed to inadequate multifunctional control strategies. Therefore, the objective of this study was to develop multifunctional myoelectric control strategies that can generate a number of output control signals. We demonstrated the feasibility of a neural network classification control method that could generate 12 functions using three EMG channels. The results of evaluating this control strategy suggested that the neural network pattern classification method could be a potential control method to support reliability and convenience in operation. In order to make this artificial neural network control technique a successful control scheme for each amputee who may have different conditions, more investigation of a careful selection of the number of EMG channels, pre-determined contractile motions, and feature values that are estimated from the EMG signals is needed.

• 대한기계학회논문집
• /
• 제12권6호
• /
• pp.1303-1311
• /
• 1988

본 연구에서는 적응제어 연삭가공 공정에 사용가능한 인프로세스 표면조도 측 정기술 개발을 목표로 하여 공학을 이용한 비접촉식 조도측정 기술의 개발을 시도하였 으며 포스트 프로세스에도 사용가능 하도록 하였다. 측정기술의 개발은 정반사광과 난반사광의 단순비교 방법 (정반사광에 대한 난반사광의 비율을 이용하는 방법)과 산 란광의 패턴인식(pattern recognition)을 이용하는 방법의 두가지로 진행되었는데, 후 자의 방법에 중점이 두어 졌으며 Beckmann의 산란이론(scattering theory)이 측정시스 템 제작의 관점에서 분석되고 응용되었다.

• 대한의용생체공학회:의공학회지
• /
• 제24권5호
• /
• pp.435-442
• /
• 2003

In this paper, biomechanical aspects of dynamic대학교postural responses against forward perturbations were experimentally determined simultaneous measurements of joint angles, accelerations. EMG activations, center of pressure(CoP) movements and ground reaction forces(GRF), Thirteen young healthy volunteers, stood on a flat platform, were translated into the forward direction by an AC servo-motor at two separate velocities(0.1m and 0.2m/s). In order to recover postural balance against the forward perturbation, joint motions were observed in the sequence of the ankle dorsiflexion, the knee flexion and then the hip flexion during the later acceleration phase. Both acceleration patterns at the heel and the sacrum were shown the forward acceleration pattern during the later acceleration phase and early of constant velocity phase as increasing platform velocity, respectively. Tibialis anterior(TA) for the ankle dorsiflexion and biceps femoris(BF) for the knee flexion. the primary muscle to recover the forward perturbation, was activated during the half of acceleration phase. Ankle strategy was used for slow-velocity perturbation, but mixed strategy of both ankle and hip used for the fast-velocity perturbation. In addition, parameters of perturbation such as timing and magnitude influenced the postural response against the perturbation.

• 한국철도학회논문집
• /
• 제12권5호
• /
• pp.772-777
• /
• 2009

지구 온난화를 경감 하기위한 차세대 동력시스템으로서 연료전지 동력시스템은 승용차를 중심으로 활발하게 개발되고 있다. 가선이 설치되어있지 않은 철로에서의 철도차량의 경우에 있어서도 연료전지 동력시스템의 적용이 선진 각국을 중심으로 연구개발 되고 있다. 본 논문에서는 가속, 타행주행 및 감속을 반복하여 주행하는 경전철에 대하여 연료전지 하이브리드 동력시스템을 적용하고자 할 때 이에 대한 설계 및 제어전략을 논하였고, Matlab/Simulink로 모델링하여 시뮬레이션을 수행하였다.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2005년도 춘계학술대회
• /
• pp.177-182
• /
• 2005

This paper examines to focus on General Strategy of e-logistics activity for SCM(Supply Chain Management) Build-up, especially the field service logistics integration. And this research analyzes the case study(Business of Strategy Group Unit) Survey involving effective logistics management that leads customer satisfaction, seeking to find out the key elements of competitive policy. Because problems arise from the differences between their goals and structures, which cause each side to feel vulnerable to opportunism or shirking of responsibilities by the other. The goal of a logistics system is to ensure that every family planning client always receives the contraceptives partner wants, and that they are in good condition and have not expired. In order to select, procure, and distribute the right quantities of the right contraceptives, managers of the logistics system must keep informed of the rates of use of each contraceptive and of the quantity of available supplies. As a result, We propose that a firm's e-logistics safe strategy is an important locus innovation and a crucial source of value creation for the firm its suppliers, partners, and customers.

• 한국항만경제학회지
• /
• 제21권3호
• /
• pp.115-148
• /
• 2005

In the liner market, a strategy is hard to sustain as competitors can easily imitate the strategy. For examples, when a number of shipping companies pursue this space exchange strategy in a liner market, their competitors are likely to build a cooperative alliance, following similar strategic pattern without any difficulty. Such strategic imitations are universal in international liner market. Therefore, the success of global alliance requires following critical considerations. First, the strategy of global alliance should be designed the way it gives the liner operators an economy of scale, which could be a key advantage in the competitive market. Second, thorough global alliance the lines should be able to improve their transport service through the reduction of operating costs and the business rationalization. The international alliance today is characterized by a strategic cooperation among a limited number of 'mega-carriers'. Such cooperation between the large-sized operators has come in many different forms. However, the trend has been towards the space exchange agreement, where a carrier on a route offers to another carrier a fixed number of spaces for a fixed period of time. the major carriers have been entered into groupings by integrating their services structures to increase market power. With reference to the above, this study has the following primary objectives: (1) to explore the present status of global alliance in liner shipping industry, (2) to prospect the future trend of the global alliance.