• Title/Summary/Keyword: 시물레이션

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Computer Simulation for Working Condition of Undergroundwork Using TOP DOWN Technique (TOP DOWN 지하공사의 작업환경체크 컴퓨터시물레이션에 관한 기초적 연구)

  • 고성석;손기상;심경수
    • Journal of the Korean Society of Safety
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    • v.10 no.3
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    • pp.96-105
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    • 1995
  • The better industry develops, the more spaces need but in the limited area. Most building become larger and more complicated if the more spaces need in the constant area. And this leads to do underground work in long period generally six(6) months for 6 basement stories due to the selection of TOP DOWN technique. Working environment in this underground area can be problems and should not be overlooked, because air quality in underground spaces become quickly worse. Recently, department name to control construction safety has been changed to ENVIRONMENT & SAFETY TEAM from SAFETY TEAM. This means that it is very important to control against environmental condition at site so much. Overall construction work as well as underground work should conform to the requirement of working environment, particularly against inhabitants around the construction area. Strut protection, one of earth protection method, in case to 40m long strut may become weaker due to thermal stress or its longitudinally compressive strain and the another one, earth anchor protection may not be applied to the site In case of encroaching on vertical underground borderline because of regulation to prohibit it. It is necessary that TOP DOWN technique should be introduced in order to solve the external and internal problem of the site such as difficulty level of the work, potential danger with excavating depth, and shortening workperiod. It is needed that improving way of working condition should be shown and simplified computer simulation program should be also provided for checking pollution level & ventilation, excluding of lighting problem here. Results measured with conformance to the Regulation for Working Environment Measurement, enforced by Ministry of Labor have been applied to the computer program developed here. Sample air taken at unit workplace which was considered as exposing condition of pollutant at breathing point and within a range of behavior of the workers, Identified exposing group in underground work, using Moded Flow Life Finally, three types of ventilation system, type I with blower & ventilator, type II natural supply with mechanical ventilation system, and type I mechanical ventilation with Drivent Fan Unit System are selected for this study.

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TLD Dosimetry in HDR Intracavitary Brachytherapy (고선량률 강내 근접치료시 열형광량계를 이용한 선량측정법)

  • Kim, Chang-Seon;Yang, Dae-Sik;Kim, Chul-Yong;Park, Myung-Sun
    • Progress in Medical Physics
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    • v.11 no.2
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    • pp.109-116
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    • 2000
  • One consideration of radiation delivery in cervical cancer is the complication of critical organs, e.g., bladder and rectum. The absorbed dose of bladder and rectum in HDR intracavitary brachytherapy is measured indirectly with TLD dosimetry A method for the complication reduction of bladder and rectum is suggested. For two-hundred cervical cancer patients, follow-up MRI images were reviewed and distances from cervical central axis to bladder and rectum and vaginal wall thickness were measured. The sealed TLDs were placed upon the gauze packing of the ovoids and the distances to the TLDs from the ovoid center were measured in the simulation film and actual doses of bladder and rectum were calculated. From published data, maximal tolerance doses of bladder and rectum were derived and based on the permissible doses per fraction in HDR brachytherapy the packing thicknesses were determined in both directions. The required minimal packing thicknesses for bladder and rectum were 0.43 and 0.92 cm, respectively. The results were compared with computer calculation using the Meisberger polynomial approach. It is our hope this study can be used for a guideline for users in clinic in estimating critical organ dose in bladder and rectum in HDR brachytherapy in vivo dosimetry.

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Design of the Advanced Mobile Teletraffic Model and Object Classes for Mobile Simulator (이동통신 시뮬레이터를 위한 개선된 텔레트래픽 모델과 객체 클래스 설계)

  • Yoon, Young-Hyun;Kim, Sang-Bok;Lee, Jeong-Bae;Lee, Sung-Chul
    • The KIPS Transactions:PartC
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    • v.11C no.4
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    • pp.509-518
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    • 2004
  • Many simulators have been developed and are being used for the complex and various mobile communication service environments. Each of these simulators has its own teletraffic model that consists of traffic source model and network traffic model. In this paper, network traffic model and traffic source model, which are based on the data gathered in real environment, are defined in order to get more accurate simulation results in the mobile communication simulation for the urban region. The network traffic model suggested in this paper reflects the hourly call generation rate and call duration time by analyzing the data collected from actually installed base station by the time and place, and the traffic source model includes the delivery share ratio and average speed information in the region where the base station is installed. This paper defined and designed Mobile Host object that reflects the suggested traffic source model, and Call Generator object that reflects the network traffic model, and other objects support both objects. Using the teletraffic model suggested in the paper, user mobility similar to real service environment and traffic characteristics can be reflected on the simulation, and also more accurate simulation results can be got through that. In addition, by using object-oriented techniques, new service feature or environment can be easily added or changed so that the developed mobile communication simulator can reflect the real service environment all the time.

Evaluating Choice Attributes of Korean Ginseng Chicken Soup as a Home Meal Replacement (HMR) Product Using Conjoint Analysis: A Case Study of Singapore Market (컨조인트 분석을 이용한 삼계탕 간편가정식의 선택속성 분석: 싱가포르 시장을 중심으로)

  • Kim, Eun-Mi;Ahn, Jee-Ahe;Lee, Ho-Jin;Lee, Min-A
    • Korean journal of food and cookery science
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    • v.32 no.5
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    • pp.609-618
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    • 2016
  • Purpose: The purpose of this study was to analyze the attributes considered important by Singaporeans in the selection of Korean ginseng chicken soup as an HMR product using conjoint analysis techniques. Methods: A total of 400 questionnaires were distributed to local consumers in April 2012, of which 324 were completed (81.0%). Statistical analyses of data were performed using SPSS/Windows 18.0 for descriptive statistics and conjoint analysis. Results: Analysis of the attributes and levels of Korean ginseng chicken soup as an HMR product for people who lived in Singapore showed the relative importance of each attribute as follows: packing (32.4%), chicken (32.1%), glutinous rice (13.8%), soup (11.6%), and ginseng (10.0%). Results showed that Singaporean consumers preferred code J's Korean ginseng chicken soups as an HMR product, which consisted of half a chicken, glutinous rice, a whole ginseng root in a soy sauce-based soup, and a partially transparent package. The most preferred Korean ginseng chicken soup gained 50.4% potential market share from choice simulation when compared with the second preferred one. Conclusion: This study has significance in that such a practical research contributes to product development of a specific Korean dish for foreign consumers. In addition, the results of this study provide useful information for the food industry for global expansion and commercialization of Korean food, thereby providing an important foundation for future development of various Korean foods as HMR products.

The Active Noise Control in Harmonic Enclosed Sound Fields (I) Computer Simulation (조화가진된 밀폐계 음장에서의 능동소음제어 (I) 컴퓨터 시물레이션)

  • Oh, Jae-Eung;Lee, Tae-Yeon;Kim, Heung-Seob;Shin, Joon
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1054-1065
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    • 1993
  • A computer simulation is performed on the effectiveness of the active minimization of harmonically excited enclosed sound fields for producing global reduction in the amplitude of the pressure fluctuations. In this study for the appreciable reductions in total time averaged acoustic potential energy, $E_{pp}$, the transducer location strategies for three dimensional active noise control is presented based on a state space modal which approximates the closed acoustic field.In this study, the above theoretical basis is used to investigate the application of active control to sound fields of low modal density. By the used of room-like 3-dimensional rectangular enclosure it is demonstrated that the reductions in $E_{pp}$ can be achieved by using a single secondary source, provided that the source is placed within the half a wavelength from the primary source and placed away from nodal line of the sound field. Concerning the reductions in $E_{pp}$ by minimzing the pressure in sound fields by the use of 3-dimensional rectangular enclosure, the effects of the number of sensors and the locations of these sensors are investigated. When a few modes dominate the response it is found that if only a limited number of sensors are located away from nodal line and located at the pressure maxima of the sound field such as at each corner of a rectangular enclosure.

Temperature and length of cold storage affect the Quality Maintenance of fresh kiwifruit (Actinidia chinensis Planch) (저온저장 온도 및 저장기간이 키위 "골드"의 품질 유지에 미치는 효과)

  • Yang, Yong-Joon;Lim, Byung-Seon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.256-261
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    • 2017
  • The effects of temperature and length of cold storage on the quality maintenance of fresh "Gold" kiwifruit were investigated. Physio-chemical properties were analyzed in kiwifruit held at $2^{\circ}C$ and $6^{\circ}C$ temperatures compared to fruit at room temperature ($20{\sim}28^{\circ}C$) during 8 weeks of storage. Low temperatures ($2^{\circ}C$ and $6^{\circ}C$) significantly delayed softening and soluble solids content (SSC) accumulation compared to higher temperature ($20{\sim}28^{\circ}C$). Physico-chemical properties of fruits, including weight losses, firmness, SSC, titratable acidity (TA), SSC/TA ratio, and flesh color properties were monitored during storage. Fast firmness loss was detected in fruit stored at higher temperatures compared to low temperature ($2^{\circ}C$). Similar results were observed for acidity according to storage temperature and length of cold storage, whereas SSC increased to the limited values (%Brix) during storage. The soluble solids content (SSC) increased markedly during the first 60 days of storage and remained almost constant thereafter for all treatments. SSC accumulation rates decreased from 5 weeks after storage probably due to differences between initial and ripe kiwifruits, and SSC decreased with each passing week due to natural starch conversion over time. The SSC/acid ratio increased from 18 to 27 until 5 weeks after storage and then slowly declined in all kiwifruit stored at different low temperatures. Sensory evaluation results showed no differences in kiwifruit flesh color stored at two storage temperatures of $2^{\circ}C$ and $6^{\circ}C$.

A architecture and control method of Streaming Packet Scheduler at 100bps for Guaranteed QoS of Internet and Broadcasting Services (인터넷 및 방송서비스의 QoS 보장을 위한 10Gbps급 스트리밍 패킷 스케줄러 구조 및 제어방법)

  • Kim Kwang-Ok;Park Wan-Ki;Choi Byeoun-Chul;Kwak Dong-Yong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.1
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    • pp.23-34
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    • 2004
  • This paper presents architecture and control method of packet scheduler to guarantee QoS of high quality streaming services in high-speed packet-switched networks. Since streaming services need far more stringent QoS requirements than the typical sort of burst data applications, they should be guaranteed minimum bandwidth and end-to-end delay bound to each flow, regardless of the behavior of other flows. To meet these requirements, a packet scheduler isolate a flow from the undesirable effects of other flows and provides end-to-end delay guarantees for individual flow and divides stringently the available link bandwidth among flows sharing the link. Until now, many vendors are developing traffic management chips running at 10Gbps, but most of chips have drawbacks to support high quality streaming services. In this paper, we investigate the drawbacks of commercial TM chips and traffic characteristic of streaming services and present implementation frameworks of the proposed packet scheduler. Finally, we analyze the simulation results of the proposed scheduler.

Comparison of physical materials using the 3D Clothing Simulation Z-weave program and its feasibility in the sustainable fashion industry (3D 의류 시뮬레이션 Z-weave 프로그램을 이용한 실물 소재 비교와 지속 가능한 패션 산업에서의 실현성)

  • Heeju Chae;Doeun Kim;Yoonji Shin
    • Smart Media Journal
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    • v.13 no.6
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    • pp.80-89
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    • 2024
  • This study aims not only to address environmental issues caused by indiscriminate fashion consumption, specifically in the context of Fast Fashion but also to find an alternative and a sustainable solution that is 'Upcycling' using the 3D clothing simulation program Z-weave. Upcycling products have limitations in that it is difficult to produce samples since finished products must be produced directly with limited materials and resources like waste clothes. To overcome these limitations, a 3D clothing simulation program is introduced to effectively utilize the limited resources of waste clothing. The purpose of this study is to confirm the similarity between a virtual fabric created through Z-weave and a real fabric, through this, to evaluate the possibility of application in the actual fashion industry. As a research method, surveys and interviews were conducted with related majors on virtual clothing created as similar as possible to actual clothing by adjusting the physical properties within the Z-weave program. This study attempted to describe the impact of digital technology on the fashion industry and how 3D clothing simulation programs can be used in sustainable fashion production.

Numerical Simulation of Normal Logging Measurements in the Proximity of Earth Surface (지표 부근에서의 노멀전기검층 수치 모델링)

  • Nam, Myung-Jin;Hwang, Se-Ho
    • Economic and Environmental Geology
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    • v.43 no.3
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    • pp.259-267
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    • 2010
  • Resistivity logging instruments were designed to measure electrical resistivity of formation, which can be directly interpreted to provide water-saturation profile. Short and long normal logging measurements are made under groundwater level. In some investigation sites, groundwater level reaches to a depth of a few meters. It has come to attention that the proximity of groundwater level might distort short and long normal logging readings, when the measurements are made near groundwater level, owing to the proximity of an insulating air. This study investigates the effects of the proximity of groundwater level (and also the proximity of earth surface) on the normal by simulating normal logging measurements near groundwater level. In the simulation, we consider all the details of real logging situation, i.e., the presence of wellbore, the tool mandrel with current and potential electrodes, and currentreturn and reference-potential electrodes. We also model the air to include the earth’'s surface in the simulation rather than the customary choice of imposing a boundary condition. To obtain apparent resistivity, we compute the voltage, i.e., potential difference between monitoring and reference electrodes. For the simulation, we use a twodimensional, goal-oriented and high-order self-adaptive hp finite element refinement strategy (h denotes the element size and p the polynomial order of approximation within each element) to obtain accurate simulation results. Numerical results indicate that distortion on the normal logging is greater when the reference potential electrode is closer to the borehole and distortions on long normal logging are larger than those on short normal logging.

The effect of global disaster competency development program on paramedic and nursing undergraduate students (글로벌 재난 역량 개발 프로그램이 응급구조과와 간호학과 학생에게 미치는 효과)

  • Kang, Sun-Joo;Piao, Mei-Hua
    • The Korean Journal of Emergency Medical Services
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    • v.18 no.1
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    • pp.83-94
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    • 2014
  • Purpose : This study assessed the improvement of competency levels for participants, as well as their satisfaction from completion of the special international disaster response program. Methods : The program structure followed an intensive two-week course that included a combination of lectures, discussions, case studies, and field trips. "ICN Framework of Disaster Nursing Competencies" was used for designing the program. A pre-post survey was done to measure the change in the competencies of students and assess their satisfaction after finishing the program. Focus group interviews were also performed to further understand the attitudes of participants toward the disaster issues. Results : The overall pre-program test score for disaster competency was $2.18{\pm}0.68$ and the post-program test score was $6.30{\pm}0.84$, which showed statistically significant gains in all competency items (p <.001). The general satisfaction of participants with the program was quite high, demonstrated by a mean score of $4.5{\pm}0.51$. The benefits for students from program participation included increased knowledge and better understanding of the important roles of international organizations and NGOs. Conclusion : The international disaster education programs are necessary to provide an opportunity for students to increase their disaster competency. In addition, future development of a unified educational competency framework is also necessary.