• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.198-201
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• 2004

Aluminum alloys have high potential for weight reduction in automotive and other applications. But aluminum alloys have relatively low tubular hydroformability which can be enhanced by conducting the hydroforming at elevated temperatures. Hot working processes are commonly used in bulk forming such as forging and rolling, but still is rare in sheet metal forming like hydroforming. In this study hydroforming test at elevated temperatures is performed by special designed induction heating system to investigate the hydroformability of aluminum alloys. The high temperature formability characteristrics are obtained by 1?fitting forming test and circular bulging test and the effects of the process parameters such as feeding amount, internal pressure and temperatures on the tubular forming limits are mainly investigated.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.206-209
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• 2004

In the hydroforming process the number of process can be reduced by combining pre-forming process and post-forming process such as the bending, piercing and the embedding process. Integrated studies on the embedding manufacturing technology have been performed by analyzing the deformed mode of the tubes and the optimal process parameters. In this study, a simulation model that can prove clamping force between the clamping element and tube has been investigated by FEM. The characteristics of the embedded parts, such as the shape of the screw tip, screw thread and shape of thread were investigated at various clamping element conditions.

• 한국식품저장유통학회지
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• 제7권2호
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• pp.228-232
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• 2000

To utilize abundant potatoes effectively, it was studied on alcohol fermentation strains which were isolated and identified. Fifteen yeast strains with high alcohol fermentation ability were isolated from rotted potatoes. Among them, two isolated strains, 5-3A and 10-4B showing the highest alcohol fermentation ability were identified as Zygosaccharomyces fermentati based on the morphological and physiological characteristics. Their optimum conditions for the alcohol fermentation in 25% glucose were pH 3.0, 30$^{\circ}C$ and 150 rpm of shaking speed, respectively.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2008년도 공동추계학술대회
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• pp.335-336
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• 2008

최근 ITS(Intelligent Transportation Systems)의 보급으로 개인의 기-종점 간 통행시간에 많은 비용절감을 가져왔다. 지금까지의 주요 최단경로알고리즘은 네트워크의 기-종점(Origin-Destination) 거리 간 최단 통행시간을 고려하여 연구되어 왔다. 하지만, 최근 대두되는 고유가 시대의 진입과 더불어 환경에 대한 인식이 높아짐에 따라 기-종점 간 통행시간만을 고려하던 기존의 방법들에서 벗어나 추가적인 요인들의 고려 필요성이 증대되고 있다. 따라서 본 연구에서는 지리정보시스템을 이용한 환경오염을 최소화하는 친환경 최단경로 탐색방법 개발을 제안하고자 한다. 이를 위하여 3D 좌표정보 도로를 활용하여, 도로구배 조건에 따른 배출가스의 증감율을 환경오염편익으로 구분하고, 이를 사회적비용으로 환산하여, 경로탐색의 추가적인 요소로 반영하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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• pp.9-13
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• 2008

충격파와 같은 moving load가 특별한 속도로 관 안을 전파한다. 이 관 안을 전파하는 moving load 속도는 flexural wave의 활성화의 정도와 큰 변형을 일으키는 공진이 발생할 가능성을 결정한다. 본 연구에서, 우리는 moving load가 관안을 통과하고 있을 때의 변위의 특별해와 공진현상이 일어날 조건을 보일 것이다. 또한 이 이론적 결과를 hydrocode를 이용하여 얻은 수치해석 결과와 비교하여 정당성을 보일 것이다. 이와 같은 결과를 바탕으로 본 연구는 원자력 발전소나 탄화수소 계열의 연료를 사용하는 산업분야에서 공진현상에 의한 대형 사고를 예방하는 목적을 가지고 있다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.737-740
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• 2000

Two groups of bacteria, harmful and useful bacteria, coexist in our body. Harmful bacteria and free radicals which cause many diseases and agings could be controlled by not synthetic materials but natural products. 50 kinds of natural products were searched for this purpose, some of them expressed bacterial controlling ability. Clostridium difficle was controlled by Paeonia Japonica and Lycii Fructus, etc., Clostridium perfringens was inhibited by Scutellaria Baicalensis and Astragali Radix, etc., and same way, Listeria monocytogenes; Paeonia Japonica and Scutellaria Baicalensis, E. coli; Scutellaria Baicalensis and Schizandrae Fructus, Staphylococcus aureus; Paeonla Japonica and Scutellaria Baicalensis, Streptococcus mutans; Coptis Rhizoma, respectively. These natural products will play an important role in bio-Industry.

• 음성과학
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• 제8권2호
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• pp.61-71
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• 2001

Speech material, which is collected from ARS(Automatic Response System), was analyzed and classified into disease and non-disease state. The material include 11 different kinds of diseases. Along with ARS speech, DAT(Digital Audio Tape) speech is collected in parallel to give the bench mark. To analyze speech material, analysis tools, which is developed local laboratory, are used to provide an improved and robust performance to the obtained parameters. To classify speech into disease and non-disease class, multi-layered neural network was used. Three different combinations of 3, 6, 12 parameters are tested to obtain the proper network size and to find the best performance. From the experiment, the classification rate of 92.5% was obtained.

• 말소리와 음성과학
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• 제7권4호
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• pp.9-16
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• 2015

In this paper, several experiments are performed according to deep neural network (DNN) based features for the performance comparison of speaker verification (SV) systems. To this end, input features for a DNN, such as mel-frequency cepstral coefficient (MFCC), linear-frequency cepstral coefficient (LFCC), and perceptual linear prediction (PLP), are first compared in a view of the SV performance. After that, the effect of a DNN training method and a structure of hidden layers of DNNs on the SV performance is investigated depending on the type of features. The performance of an SV system is then evaluated on the basis of I-vector or probabilistic linear discriminant analysis (PLDA) scoring method. It is shown from SV experiments that a tandem feature of DNN bottleneck feature and MFCC feature gives the best performance when DNNs are configured using a rectangular type of hidden layers and trained with a supervised training method.

• 한국조경학회지
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• 제33권2호
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• pp.92-99
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• 2005

The main gate of a university is a element of landscape which improves the quality of campus as well as demarcates the boundary and publicizes the image of university. Therefore, each university strives to differentiate its main gate from that of other universities with a unique form. This research investigates the signs and symbols shown at the university's main gate of 18 universities in Korea, and also presents useful design tips with the objective of bearing the spirit of the campus and its founding ideology. The results of this research as follows: Icons of Sign for 18 universities can be classified into five separate categories: things, human, animal, character, and metaphor. Examples of the 'things' icons include a pen nib, the sun, the cross, a big bell, and so on. Also, the meaning of the represented symbols can be grouped in three separate categories: university's development, contribution to society, and mining of knowledge. From the three category, university development symbol is the most likely to be used.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.71-75
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• 1999

In this paper, we present the 3DOF force-reflecting interface which allows to acquire force of object within a virtual environment. This system is composed of device, virtual environment model, and force-reflecting rendering algorithm. We design a 3 DOF force-reflecting device using the parallel linkage, torque shared by wire, and the controller of system applied by impedance control algorithm. The force-reflecting behaviour implemented as a function position is equivalent to controlling the mechanical impedance felt by the user. Especially how force should be supplied to user, we know using a God-Object algorithm. As we experiment a system implemented by the interface of 3D virtual object and 3DOF force-reflecting interface, we can feel a contact, non-contact of 3D virtual object surface and sensing of push button model.