• 한국근적외분광분석학회:학술대회논문집
• /
• 한국근적외분광분석학회 2001년도 NIR-2001
• /
• pp.1192-1192
• /
• 2001

Usually there are many furnaces in a ethylene plant and the performance of total furnaces can be improved if that of each furnace is monitored and controlled. For this purpose real-time data for the effluent of each furnace is necessary. However, it is very difficult to analyze the total effluent stream of a ethylene furnace by real-time because it is composed of so many components including heavy hydrocarbons. Fortunately, component data for lighter hydrocarbons is much more important than that of heavier ones for ethylene furnace. In ordinary case, the on-line measurement of light hydrocarbons is performed by on-stream gas chromatography, after separating gas-phase part from effluent. The main and important components of gas-phase are Methane, Ethane, Ethylene, and Propylene. If we can use Near-infrared spectroscopy for measuring those components within good reproducibility, shorter analysis time, better repeatability, easier maintenance and lower cost will make Near-infrared (NIR) analyzer replace on-stream gas chromatography in this process. Although it is known to be very difficult to measure gas components because of very weak absorption in Near-infrared region, we have studied the feasibility of the application of NIR for the measurement of gas-phase hydrocarbon in the effluent of ethylene furnace. The samples were obtained from actual process and NIR spectra were collected over 1100 to 2500nm range. NIR spectra and calibrations showed and demonstrated the possibility of extending NIR spectroscopy to the measurement of gas-phase hydrocarbon in the effluent of ethylene furnace.

• 한국조명전기설비학회:학술대회논문집
• /
• 한국조명전기설비학회 2004년도 학술대회 논문집
• /
• pp.371-374
• /
• 2004

Induction motors are a critical component of many industrial processes and are frequently integrated in commercially available equipment. Safety, reliability, efficiency, and performance are some of the major concerns of induction motor applications. Preventive maintenance of induction motors has been a topic great interest to industry because of their wide range application of industry. Since the use of mechanical sensors, such as vibration probes, strain gauges, and accelerometers is often impractical, the motor current signature analysis (MACA) techniques have gained murk popularity as diagnostic tool. Fault tolerant control (FTC) strives to make the system stable and retain acceptable performance under the system faults. All present FTC method can be classified into two groups. The first group is based on fault detection and diagnostics (FDD). The second group is independent of FDD and includes methods such as integrity control, reliable stabilization and simultaneous stabilization. This paper presents the fundamental FDD-based FTC methods, which are capable of on-line detection and diagnose of the induction motors. Therefore, our group has developed the embedded distributed fault tolerant and fault diagnosis system for industrial motor. This paper presents its architecture. These mechanisms are based on two 32-bit DSPs and each TMS320F2407 DSP module is checking stator current, voltage, temperatures, vibration and speed of the motor. The DSPs share information from each sensor or DSP through DPRAM with hardware implemented semaphore. And it communicates the motor status through field bus (CAN, RS485). From the designed system, we get primitive sensors data for the case of normal condition and two abnormal conditions of 3 phase induction motor control system is implemented. This paper is the first step to drive multi-motors with serial communication which can satisfy the real time operation using CAN protocol.

• 한국생활과학회지
• /
• 제24권1호
• /
• pp.69-77
• /
• 2015

The study will furnish university students-oriented accessary market with preliminary data by virtue of university students' wearing accessary conditions. It conducted by 151 university students in Jeon-Nam and Jeon-Buk during october through november, 2014. The questionnaire is composed of 17 questions and used 151 out of 152 copies as the final data, except for one insufficient reply. The analysis method carried out a technological statistics such as frequency count, percentage, average and t-test for every questions, used by SPSS 20.0. The investigation result is as follows; The overall numbers of answerers were 151 people, 36 male and 115 female, and showed that they purchase accessaries of less than 20,000won in a jewelry shop. According to the 86.1% of university students' answers, the most well known brand is OST and then Metrocity(76.2%), Swarovski(68.9%) came after. The most visit count is to a jewelry shop, once or twice in a month, on-line shopping malls and department stores came after. Rings and bracelets are purchased once or twice in a month, and earrings are mainly put on. When purchasing accessaries, quality and scarcity design are the most significant conditions, getting the information through internet and fashion magazines. The ground of purchasing accessaries is for self-contentment and for coordinating with their fashion, and also the difficult maintenance as well as untangled wool are defined as uneasiness of using accessaries. Furthermore, the original goods are preferred for rings and necklaces, unlike earrings and bracelets.

• Safety and Health at Work
• /
• 제2권1호
• /
• pp.39-51
• /
• 2011

Objectives: This study was designed to evaluate exposure levels of various chemicals used in wafer fabrication product lines in the semiconductor industry where work-related leukemia has occurred. Methods: The research focused on 9 representative wafer fabrication bays among a total of 25 bays in a semiconductor product line. We monitored the chemical substances categorized as human carcinogens with respect to leukemia as well as harmful chemicals used in the bays and substances with hematologic and reproductive toxicities to evaluate the overall health effect for semiconductor industry workers. With respect to monitoring, active and passive sampling techniques were introduced. Eight-hour long-term and 15-minute short-term sampling was conducted for the area as well as on personal samples. Results: The results of the measurements for each substance showed that benzene, toluene, xylene, n-butyl acetate, 2-methoxy-ethanol, 2-heptanone, ethylene glycol, sulfuric acid, and phosphoric acid were non-detectable (ND) in all samples. Arsine was either "ND" or it existed only in trace form in the bay air. The maximum exposure concentration of fluorides was approximately 0.17% of the Korea occupational exposure limits, with hydrofluoric acid at about 0.2%, hydrochloric acid 0.06%, nitric acid 0.05%, isopropyl alcohol 0.4%, and phosphine at about 2%. The maximum exposure concentration of propylene glycol monomethyl ether acetate (PGMEA) was 0.0870 ppm, representing only 0.1% or less than the American Industrial Hygiene Association recommended standard (100 ppm). Conclusion: Benzene, a known human carcinogen for leukemia, and arsine, a hematologic toxin, were not detected in wafer fabrication sites in this study. Among reproductive toxic substances, n-butyl acetate was not detected, but fluorides and PGMEA existed in small amounts in the air. This investigation was focused on the air-borne chemical concentrations only in regular working conditions. Unconditional exposures during spills and/or maintenance tasks and by-product chemicals were not included. Supplementary studies might be required.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.623-628
• /
• 2007

도시 대중교통을 주도하는 도시철도에서의 중요한 기능인 신호 연동장치의 주요 논리 회로 중 가장 취약한 3, 4호선의 소형 (Non-Vital) 계전기를 성능이 향상된 전자연동장치(PLC)로 개량함으로서 사전 장애 발생요인을 제거, 열차 안전운행 확보는 물론 설비의 현대화로 업무 향상에 기여하고 신호설비 유지 보수의 합리화 및 효율화를 기할 수 있도록 신호설비의 기능개선 및 발전 방안이 되도록 하였다. 특히 고장 발생 빈도를 낮추기 위한 방안과 설비 보완 및 신설 등 종합적이고 실현 가능한 설비를 구현하고자 하였으며, 기존의 노후된 신호시설이나 교체 예정인 신호 설비들을 효율적으로 개량하기 위한 방안으로 신호 관련기술기준과 표준을 바탕으로 신호시스템의 합리적 발전에 일익을 담당코자 하였다.

• 경영정보학연구
• /
• 제11권1호
• /
• pp.145-160
• /
• 2009

본 연구에서는 von Hippel(2005)의 사용자 혁신 이론을 바탕으로 LBS 분야의 대표적 응용 서비스인 자동차 네비게이션 산업에서 특히 지도 중심의 콘텐츠 확보와 개발을 위한 사용자 혁신 활용 사례를 발굴하고자 한다. 사용자 혁신에 관한 von Hippel의 7가지 특성을 기준으로 M&Soft의 자동차 네비게이션 제품 개발 및 유지 보수 과정을 분석해본다. 이를 통해, 사용자 혁신의 성공적인 활용을 위한 판매자의 3가지 전략적 대응 중, M&Soft는 사용하기 쉬운 정보 기술 플랫폼을 제공하여 회원들이 쉽게 각종 지도 및 이동상의 정보나 아이디어들을 제공하도록 유도하는 정도에 국한되어 있음을 확인하기도 하였다. 본 연구의 의의는 실물 제품을 바탕으로 전개된 von Hippel의 이론을 인터넷 기반의 콘텐츠 서비스가 점점 중요해지는 추세에 맞춰 디지털 서비스 및 제품에 적용시켜 보았다는 점이다.

• 한국콘텐츠학회논문지
• /
• 제2권4호
• /
• pp.51-58
• /
• 2002

전자상거래 사용자의 폭발적인 증가는 전자상거래 시스템의 급격한 로드 증가와 네트워크 트래픽을 증가시키고 있다. 또한 전자상거래 시스템에서 동영상을 포함한 자료가 점차 늘어나고 있고 이에 따라 인터넷 서비스 제공업자들은 시스템의 관리와 회선의 유지를 위해 막대한 비용을 지불하고 있다. 이러한 시스템의 로드와 네트워크의 트래픽 증가는 웹 고객의 서비스 요청에 대한 응답 속도의 지연을 가져오게 되며 이는 고객만족도를 감소시켜 e-비지니스 기업의 경쟁력을 떨어뜨리는 중대한 요인으로 작용하고 있다. 본 연구에서는 마이크로소프트사의 최신 버전인 닷넷을 기반으로 한 전자상거래 시스템에서, 응답 지연 속도를 개선한 전자상거래 시스템을 설계하고 실험을 통해 성능을 분석하였다. 실험 결과 제안한 시스템은 웹 고객의 다양한 요구에 대해 개선된 응답 속도와 빠른 적응성을 가질 수 있으며, 특히 전자상거래 시스템에 대해 동시에 발생하는 다수의 다중 사용자의 요구로 인해 발생되는 응답 속도의 지연을 막을 수 있을 것으로 기대된다.

• 한국항해항만학회지
• /
• 제26권4호
• /
• pp.465-472
• /
• 2002

워터프린트는 도심 및 내륙지역과는 다른 독특한 기후특성을 가지고 있으며 이를 고려하지 않고 개발할 경우 시설물의 하자발생, 에너지 및 유지관리비용의 상승을 초래하게 됨은 물론 배후지, 도시기후에 악영향을 미치게 된다. 본 연구는 부산지역의 10개 기상관측지점을 해안선에서 거리에 따라 워터프린트 및 내륙지역으로 분류하고 5년 간의 기상데이터를 이용하여 워터프런트의 기후특성에 대해 검토한다. 또 한 워터프런트 지역임에도 내륙지역과 유사한 기후특성이 나타나고 있는 대연지점을 대상으로 기후특성변화의 원인에 대해 검토한다.

• Journal of Astronomy and Space Sciences
• /
• 제32권3호
• /
• pp.237-245
• /
• 2015

A strategy is needed for a regional survey of geosynchronous orbits (GSOs) to monitor known space objects and detect uncataloged space objects. On the basis of the Inter-Agency Debris Committee's recommendation regarding the protected region of geosynchronous Earth orbit (GEO), target satellites with perigee and apogee of $GEO{\pm}200km$ and various inclinations are selected for analysis. The status of the GSO region was analyzed using the satellite distribution based on the orbital characteristics in publicly available two-line element data. Natural perturbation effects cause inactive satellites to drift to two stable longitudinal points. Active satellites usually maintain the designed positions as a result of regular or irregular maneuver operations against their natural drift. To analyze the detection rate of a single optical telescope, 152 out of 412 active satellites and 135 out of 288 inactive satellites in the GSO region were selected on the basis of their visibility at the observation site in Daejeon, Korea. By using various vertical view ranges and various numbers of observations of the GSO region, the detection efficiencies were analyzed for a single night, and the numbers of follow-up observations were determined. The orbital estimation accuracies were also checked using the arc length and number of observed data points to maintain the GSO satellite catalog.

• 산업경영시스템학회지
• /
• 제40권4호
• /
• pp.55-66
• /
• 2017

Korean small and medium sized software companies have tried to export their solutions or services to overseas markets. In 2016, exports of the software industry increased by 6.0% from the previous year, and the value added of the industry was 2.2 times higher than that of the manufacturing industry. From a long-term perspective, it is important to secure a global competitive advantage in order to sustain the export high value-added of the software industry. The obstacles to entry into the overseas market of small to medium enterprises are as follows: first, difficulty in product development and localization of marketing; second, lack of investment for overseas expansion; and finally, competitiveness of software technology. In particular, To overcome such obstacles, Korean small and medium sized software companies should increase the technical perfection and secure software export competitiveness. The paper presents a payment settlement framework enabling adaptive reuse and semiautomatic development of global payment settlement services. The quantitative and qualitative evaluation results are presented with domestic and overseas case studies as follows: Firstly, semi-automatic development is realized successfully by applying the framework. Secondly, it is possible to maintain consistent quality of software and to deliver maintenance services without relying on the internal human resources. Thirdly, it is possible to reduce the project duration of the same development cope to less than 50% by applying the framework. Finally, because it is based on BPMN 2.0, which is a high level design diagram, it is expected that it will be easy to implement through components connection and reduce difficulties in technology transfer and localization. Also, at the time of runtime operation, it will be effective to understand the design idea easily and to carry out additional developments without human resource who participated in the initial project.