압출성형공정으로 제조한 선식 팽화스낵의 특성

장윤석,류기형 公州大學校 工學硏究院 生産技術硏究所 2003 論文集 Vol.11 No.-

Sunsik extrudate was prepared by mixture of cereal and vegetable by using an experimental twin-screw extruder. Extrudate properties such as expansion ratio, density and bending strength were analyzed. Extrusion process conditions were moisture(20%, 25%), barrel temperature(70℃, 90℃, 110℃) and vegetables content(0%, 10%, 20%). Expansion ratio decreased as adding vegetable mix and increased as water content increased. Expansion ratio was the highest in water content 25% and barrel temperature 90℃. Density increased with the increase in water content and vegetable mix. Bending strength decreased by increasing water content and vegetable mix content. It was the lowest in bending strength that extrusion conditions were water content 25%, vegetable mix content 20% and barrel temperature 110℃. In conclusion, physical properties of puffed Sunsik snack could be controlled by the ratio of cereal and vegetable mix and extrusion process variables such as barrel temperature, moisture and screw speed etc.

Experimental Study on Dynamic Crack Growth at 3PB Ductile Steel Specimens

Cho, J. U. 公州大學校 工學硏究院 生産技術硏究所 2005 論文集 Vol.13 No.-

Dynamic crack propagation in ductile steel is investigated by means of impact loaded 3 point bending specimens. Results from experiments and numerical simulations are compared. The specimen has the size 320x75 mm with a thickness of 10 mm. A modified 3PB specimen design with reduced width at the ends has been developed to avoid the influence of the uncertain boundary conditions at the impact heads. One static and two dynamic experiments with impact velocities of 30.2 m/s and 45.2 m/s are carried out. High speed photography is used to obtain crack growth and crack tip opening displacement data. Direct measurement of the relative rotation of the two specimen halves is made using by Moire interference pattern. The fracture surfaces of shear lip are obtained for all three loading conditions. The experiments indicate no or only a slight influence of the loading rate on the crack propagation.

Uni-Class를 위한 컨텍스트 인식 시스템

임재현 公州大學校 工學硏究院 生産技術硏究所 2004 論文集 Vol.12 No.-

In this paper we propose a unified context-aware application model which is an essential part to develop various applications in ubiquitous computing environment. The proposed model affirms the independence between sensor and application by using unified context in the form of external context and internal context. It also ensures that application exploits relatively accurate context to trigger personalized services. To show usefulness of the proposed model, we apply it to the sensors and applications the ubi-class, a testbed for ubi-class system applications.

협력적 필터링 기법을 이용한 P2P 모바일 에이전트 기반 서비스 처리 모델

윤효근,이상용 公州大學校 工學硏究院 生産技術硏究所 2004 論文集 Vol.12 No.-

Context-awareness is an important element that can provide service of good quality according to user's surrounding environment and status in ubiquitous computing environment. Information gathering tools for context-awareness use small size mobile devices which has a mobile agent. Now, a mobile agent is consuming much times and expense to collect and recognize each user's context information. Therefore, needs research about model to reduce mobile agent's load and to recognize user's context information in rapid time. This paper proposes a P2P mobile agent model that mixes filtering technique and a P2P agent in mobile agent. The proposed model analyzes each user's context information in uniformity area and makes groups with similar preference degree. This model continuously observes and learn users' action and service, and measure new interrelation.

바나듐 산화막을 활용한 습도센서의 제조에 관한 연구

이승철,최복길,김남철 公州大學校 工學硏究院 生産技術硏究所 2004 論文集 Vol.12 No.-

Vanadium oxides have been widely used in a variety of technological applications such electrochromic devices as infrared detectors and are expected as a material suitable for gas sensing applications. Thin films of Vanadium oxide (VOx) have been deposited by r.f magnetron sputtering under different oxygen partial pressure ratios(0%, 10%) and substrate temperatures(27℃, 400℃). Humidity-sensitive properties of resistive sensors having interdigitated electrode structure are characterized. Our sensors show good response to humidity over 20%RH to 80%RH Vanadium oxide films deposited with 0%O2 partial pressure at 400℃ exhibit greater sensitivity to humidity change than others.

부가채널공격을 고려한 타원곡선 연산 H/W 구현 방안

양종원,이창원,서창호 公州大學校 工學硏究院 生産技術硏究所 2004 論文集 Vol.12 No.-

암호 알고리즘이 장착된 하드웨어를 통한 신뢰할 수 있는 보안 서비스를 제공하기 위해서는 부가채널공격에 대한 이해와 이에 대비한 암호 알고리즘이 개발이 필수적이다. 본 논문에서는 타원곡선 연산 H/W 설계하기 위해 부가 채널에 안전한 공격 방법에 대해서 살펴 본다. 또한 효율적인 RSA 암호 알고리즘을 구현하기 위해서 몽고메리 알고리즘의 정확한 분석을 포함하여 성능 개선을 위한 구현 방법을 정립했다. ECC(Elliptic Curve Cryptography)는 소인수분해 난제를 이용하는 RSA 암호 기법과는 다르게 타원 곡선에서의 이산 대수 해결 난제를 이용한 암호 기법으로, RSA에 비해 적은 키 길이로서 동등한 안전도를 제공한다. 그리고 타원곡선의 효율적인 측면에서 구현 몯ㄹ에 관한 연구하였으며, 타원곡선 스칼라 곱셈 알고리즘이 부가 채널 공격인 시차 공격과 전력 분석 공격에 안전하기 위한 일반적인 조건과 H/W 구현 방안에 대해 제시한다.

X 염색체-연관 Microsatellite의 Multiplex PCR Kit 제조

신상희,한윤희,이경주,정기화 公州大學校 工學硏究院 生産技術硏究所 2003 論文集 Vol.11 No.-

The microsatellite(short tandem repeat: STR) markers are widely dispersed in the human genome and have been extensively studied and applied to forensic analysis and human identification. The usefulness of the X chromosomal STRs for forensic purposes seems to be restricted, but may be valuable in paternity cases where the disputed child is female. In the present study, two kits of triplex PCR (Triplex 1: DXS6807, DXS6810 and DXS6789; Triplex 2: DXS7132, HPRTB and DXS9902) and one kit of duplex PCR(DXS1214 and DXS1227) were were deviced. Using the kits, population genetic data wereanalyzed for the six X-microsatellites in sample of 401 unrelated Koreans. The exact test for female genotyping data showed no significant deviation from the Hardy-Weinberg equilibrium(P≥0.01). Details of X chromosomal STRs in Koreans would be useful in paternity tests and forensic purposes as well as whole X-chromosomal mapping studies

인터넷 기반 자바 3D 가구 배치 프로그램의 개발

가대현,이경희,허원 公州大學校 工學硏究院 生産技術硏究所 2003 論文集 Vol.11 No.-

This paper presents a development process of Internet-Based Java 3D program. Java 3D can display 3-dimensional objects on a web browser. This advantage provides easy accessibility to the Internet customers. A furniture industry is a good domain to apply java 3D technology. The 3D objects of furniture can be displayed on web-browser. The customers can select furnitures and arrange them on the Internet. The virtual reality can provide opportunity of room interior design even before the customers really visits the display show window. The features for the program are extracted in the design stage and the graphic user interface in realized. About 200 furniture pieces are modelled as library components to arrange. The Performance of the program was successful.

하수슬러지 소각재의 재활용에 관한 연구

전기석,이기환 公州大學校 工學硏究院 生産技術硏究所 2003 論文集 Vol.11 No.-

This experimental study on the incineration ash and sintering pellet from sewage sludge was carried out to evaluate the possibility of recycling in sewage sludge disposal. The samples used in this study were raw sewage, its incineration ash and sintering pellet. The characteristics of the three sample types were identified using X-ray diffraction(XRD), atomic absorption spectroscopy(AAS), and inductively coupled plasma spectroscopy(ICP). The chemical compositions of all three sample types were similar in their clay component except for a high content of organic materials in the sewage sludge. According to the fireproof bricks test method( KS L 5105 Korea), the compressive strengths of incineration ash with sintering temperature were measured. It was found that the compressive strength depends on the sintering temperature. These results prove that the incineration ash and sintering pellet have a sufficient potential for use as a constructional material.

방열핀 언로딩 자동화장치 개발

전의식 公州大學校 工學硏究院 生産技術硏究所 2005 論文集 Vol.13 No.-

According to the development of the heat sink technology, the making of heat sink pin consist the heat sink is rapidly increased. But the current manufacture machine drops pins into the box directly, there is extra work to loading the pins and this will induce the lose of man cost and work time. So in this study, the target focused the economic part like cost and time by developing the radiator pin unloading system. In the beginning of the graduate project, the concept design was needed. First of all, the twisting angle of guide bar and the setup position of driving part was suitably designed. After making prototype, the reliability test of table and driving part (sensor, cylinder,1 solenoid valve) was performed. As a result, the performance of loading the radiator pin was shown over 3 times compare to the former days.