• 대한토목학회논문집
• /
• 제34권1호
• /
• pp.329-332
• /
• 2014

세계 고속철도 시장의 대용량 수송 및 고속화 추세에 따라 개술개발 경쟁이 가속화되는 시점에서 국내외시장 환경의 대처와 신성장산업으로의 육성을 위한 신기술 개발의 필요성에 따라 동력분산형 고속철도시스템(최고시험속도 430km/h, 최고영업속도 370km/h)의 핵심기술개발로 HEMU-430x가 상용화를 앞두고 있다. 이는 철도선진국으로의 도약과 국내시장 뿐 아니라 세계시장 진출 도모에 계기가 될 수 있을 것으로 기대된다. 이에 본 연구에서는 고속철도의 국내 및 해외시장 규모를 파악하여 국내외 동력분산형 고속철도 도입을 대비한 기초자료로써 활용하고, 텍스트 마이닝 기법을 통한 동력분산형 고속열차의 차별화된 마케팅 전략을 수립하여 국내 시장에서의 성공적인 도입과 해외시장 진출을 위한 발판을 마련하고자 한다.

• 한국근적외분광분석학회:학술대회논문집
• /
• 한국근적외분광분석학회 2001년도 NIR-2001
• /
• pp.1616-1616
• /
• 2001

To select kernels for breeding that have required constituent content from either naturally distributed samples or artificially mutated ones, it is necessary to process batch samples in a short time. The constituent content of single-kernel grains such as wheat and rice has been determined using conventional bench type NIR instruments; however, it takes a lot of time and effort. Shizuoka Seiki (Fukuroi-city, Japan) and NFRI (National Food Research Institute) of MAFF (Ministry of Agriculture, forestry and Fisheries of Japan) have jointly developed a continuous high-speed single-kernel brown rice sorting machine based on rice protein content. It consists of several sections such as a feeding mechanism, measuring unit, sorting mechanism and controlling PC. The feeding mechanism picks up single-kernel brown rice from the hopper (maximum of 5kg storage capacity) and sends it to the measuring unit. A spectrum of the brown rice is obtained in the measuring unit, which consists of a near-infrared array sensor. The brown rice is then sorted in the sorting mechanism based on its protein content estimated by the controlling PC. In the present study, measuring speed was approximately 500ms for the full spectrum range and overall sorting speed was approximately 2.8s for one kernel. Accuracy of estimation was approximately SEP=0.5% of dry matter protein content for nonglutinous rice.

• 한국안전학회지
• /
• 제10권3호
• /
• pp.30-41
• /
• 1995

This paper proposed a simple method for measuring surface roughness of ground surface. Utilizing non-contact in-process measuring system using the diode laser. The measurement system is consisted of a laser unit with a diode laser and a cylindrical lens, a detecting unit with polygon mirror and CCD array sensor, and a signal processing unit with a computer and device. During operation, this measuring system can provide information on surface roughness in the measuring distance with a single sampling and simultaniously monitor the state of the grind wheel. The experimental results, showed that the Increase of the feed rate and the dressing speed an caused increase in the surface roughness and when the surface roughness is 4Rmax-10Rmax, the cutting speed is 1653m/min-1665m/min, the table speed is 0.2n1/min -0.9m/min, the dressing speed is 0.2mm/rev～0.4mm/rev, the stylus method and the in-process method can be obtained the same results. Thus, under limited working conditions, using the proposed system, the surface roughness of the ground surface during cylindrical grinding can be obtained through the in-process measurement method using the diode laser.

• 생물환경조절학회지
• /
• 제3권1호
• /
• pp.1-9
• /
• 1994

본 연구는 상대적으로 활하중의 영향이 민감하게 작용하는 농업시설의 합리적 구조설계를 위하여 우리나라 60개 지역의 자료를 사용하여 중요한 설계하중의 결정요인인 단위적설중량, 순간최대풍속 및 최대신적설심의 그 적용에 관하여 검토하였고, 얻어진 결과를 요약하면 다음과 같다. 1. 적설심에 다른 단위적설중량을 분석한 결과 적설심에 따른 차이는 발견할 수 없었고 대체적으로 정규분포를 이루고 있다. 평균기온에 의하여 단위중량을 구분해본 결과 -1$^{\circ}C$ 이상에서는 단위중량이 평균 0.91kg/cm/$m^2$, -1$^{\circ}C$ 이하에서는 평균 0.58kg/cm/$m^2$로 나타나 기온에 의한 차이가 명확했다. 2. 평균최대풍속과 순간최대풍속과의 관계를 도출하여 회귀식을 유도한 결과, 일반적으로 사용하고 있는 순간최대풍속 관계식과는 약간의 차이를 보였다. 해안지방과 내륙지방에 2개지역으로 구분하여 순간최대풍속 관계식을 유도하였다. 3. 재현기간별 최대적설심과 최대신적설심을 비교한 결과, 눈이 적은 지방에서는 큰 차이가 없으나, 비교적 눈이 많은 지방의 경우 재현기간 8년에서는 24.6cm, 57년에서는 45.6cm로 큰 차이를 보여, 난방 및 적절한 관리를 전제로 설계하면 신적설에 의하여 설계하중을 크게 감소시킬 수 있음을 나타냈다. 4. 기존식과 수정식의 설계풍속(진주지역) 및 최대적설심과 최대신적설심(서산지역)의 적용시, 2연동아치형시설의 부재사용량은 각각의 경우에 대하여 +0.3배, -0.3배이었고, 2연동지붕형 시설의 부재사용량은 각각 +0.3배, -0.1배이었기 때문에 시설의 특성에 맞는 설계자료의 선정이 매우 중요하다.

• 전자공학회논문지SC
• /
• 제37권4호
• /
• pp.35-41
• /
• 2000

본 논문에서는 유한체 GF(2/sup m/)상에서 두 다항식의 승산 알고리즘을 제시하였다. 이 알고리즘은 반복적인 배열로 병렬 승산을 효과적으로 실현하며, 동일한 시간에 고속 동작을 실현한다. 제시된 승산기는 승산연산부와 mod연산부, 원시 기약다항식연산부로 구성하였다. 승산연산부는 멀티플렉서, X-OR게이트, AND게이트, MUX로 구성하였으며, mod연산부는 AND게이트, X-OR게이트로 구성하였다. 또한 본 논문에서 제시한 승산에는 효과적인 파이프형을 도입하였다. 도출된 모든 승산기는 고속 동작하며, 회로 복잡성이 감소한다. 셀들의 내부결선도는 VLSI 실현에 적합하도록 규칙적으로 구성되었다.

• 대한전기학회논문지:전력기술부문A
• /
• 제48권5호
• /
• pp.636-642
• /
• 1999

The synthesis of the 3D images is the most important part of the virtual reality. The ray tracing is the best method for reality in the 3D graphics. But the ray tracing requires long computation time for the synthesis of the 3D images. So, we implement the ray tracing with software and hardware. Specially we design the hit-test unit with FPGA tool for the ray tracing. Hit-test unit is a very important part of ray tracing to improve the speed. In this paper, we proposed a new hit-test algorithm and apply the parallel architecture for hit-test unit to improve the speed. We optimized the arithmetic unit because the critical path of hit-test unit is in the multiplication part. We used the booth algorithm and the baugh-wooley algorithm to reduce the partial product and adapted the CSA and CLA to improve the efficiency of the partial product addition. Our new Ray tracing processor can produce the image about 512ms/F and can be adapted to real-time application with only 10 parallel processors.

• 한국태양에너지학회 논문집
• /
• 제39권3호
• /
• pp.19-27
• /
• 2019

In commercial areas, outdoor units are typically installed close to one another in the narrow space between buildings due to insufficient regulations. This makes it difficult to ventilate the discharge airflow, which may lead to deterioration of the performance of outdoor units. This study conducted CFD simulation to analyze the thermal environment according to the installation distance of the outdoor unit. The outdoor unit was installed in the space between buildings, and the thermal environment was analyzed by changing installation distance and wind speed. The performance of the outdoor unit was evaluated by measuring the on-coil temperature. The results show that the closer the distance between outdoor units, the higher the condenser on-coil temperature. Also, the on-coil temperature appeared to rise dramatically at lower wind speed.

• 한국정밀공학회지
• /
• 제30권7호
• /
• pp.673-678
• /
• 2013

Driving gear units can be affected by various problems, including those associated with external or internal defects in the bearing, problems with the lubricant oil, high-loading of the railway, and frequent impacts generated by rail joints. Temperature monitoring is a basic method in diagnosing abnormal conditions in the reduction gear and other components. This paper describes a new wireless monitoring system for the temperature diagnosis of abnormal conditions of the reduction gear. Integrated circuit (IC)-type temperature sensors were installed in the reduction gear box of a high-speed railway car. The temperature data from the reduction gear were acquired and analyzed in situ during high-speed rail operation. Analysis of these data was used to alert the driver and/or maintenance personnel when problems occurred.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 Handout for 2000 Inter. Machine Tool Technical Seminar
• /
• pp.109-115
• /
• 2000

The spindle unit is core parts in high precision machine tools. Diverse static, dynamic and thermal charateristics of spindle unit are needed for special purpose of machine tools. Compromise between those charateristics will be done in concept design phase. High static stiffness at spindle nose may be very important performance for heavy cutting work. High dynamic stiffness is also useful to high precision and high speed machine tools. Improvement of thermal charateristics in spindle lead to high reliability of positioning accuracy. For high speed spindle structure, the design parameter such as, bearing span, diameter, bearing type and arrangement, preload, cooling and lubrication method should be in harmony.

• 한국자동차공학회논문집
• /
• 제8권1호
• /
• pp.63-71
• /
• 2000

A shift control algorithm of a newly developed two-speed gear shift system is proposed for electric vehicle applications. The algorithm is formulated according to the motor torque map and optimized to obtain the adequate propulsion characteristics for vehicle. Two speed gear system with shift control algorithm has proved greater efficiencies in terms of energy economy with its simplified hardware and software structures. The gear shifting is designed to be carried out by an actuator and the control signal from a vehicle control unit equipped with $\mu$-processor. The results of performances and efficiency of the algorithm by simulation and vehicle test are described.