• Title/Summary/Keyword: preliminary data

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Supersonic Flow Air Data Acquisition Algorithm Using Total Pressure Sensors (전압력센서를 적용한 초고속 유동데이터 산출 알고리즘)

  • Choi, Jong-Ho;Lee, Jae-Yoon;Yoon, Hyun-Gull;Lim, Jin-Shik
    • Journal of the Korean Society of Propulsion Engineers
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    • v.15 no.5
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    • pp.60-65
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    • 2011
  • The development of an air data acquisition algorithm has been described in the supersonic flow at the preliminary design stage with pressure data acquisition device composed of major three total pressure sensors and two static pressure sensors which are installed on the surface of a cone type supersonic inlet. Through this algorithm, Mach number, angle of attack and sideslip angle can be very easily derived with simple interpolation algorithm and predefined data tables. The available range of Mach number is 1.6 to 4.0, angle of attack, $-12^{\circ}$ to $12^{\circ}$ and sideslip angle, $-12^{\circ}$ to $12^{\circ}$. In preliminary design stage, the data tables applied to the developed algorithm are constructed with data driven by Taylor Maccoll equation. The present algorithm would be useful to get supersonic flow air data for the various aerial vehicles and their flight tests.

The Study of the Deaths occurred at Korean sea (우리나라 해상에서 발생한 사망사고 유형에 관한 연구)

  • Kim, Il-Pyeong;Park, Hee-Kyung;Chae, Jong-Min
    • Journal of forensic and investigative science
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    • v.2 no.2
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    • pp.67-91
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    • 2007
  • The nature of deaths occurred at sea may be revealed the differences from that in the land, but there is no comprehensive statistical analysis of deaths occurred at Korean Sea so far. Therefore, the cases of deaths or missing in the period 1993 - 2006 were analyzed by the cause, place of death, and results of preliminary investigation. In the period from 1993 to 2006, over 1000 peoples were died or missing every year. The cases of marine safety accidents including self-carelessness and mishap were approached over 60% and cases of homicide were less than 1%. The closure cases of preliminary investigation were reached over 70% and the most of deaths occurred in fishing vessels (the range of 20 ~ 99 tonnage). The suspension cases of preliminary investigation were reached to 70% of all missing and drowning cases. The results showed that the most of deaths occurred at sea could be prevented by the safety regulations including mandatory report of accidents, marine safety education and training, punishment the people responsible for the accidents. For the unidentified bodies, data should be collected and recorded for the future identification. The crime scene investigators should be trained to ensure the quality of their professional skills regularly.

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Analysis of Installation Status and Application of GIS for Preliminary Risk Assessment of Underground Storage Tanks in Chuncheon City (춘천시의 지하 저장 탱크의 예비적 위해성 평가를 위한 설치 현황 분석 및 지리정보시스템의 적용)

  • Kim, Joon-Hyun;Han, Young-Han;Lee, Jong-Chun;Kwon, Young-Sung;Lee, Kwang-Yeon
    • Journal of Industrial Technology
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    • v.22 no.A
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    • pp.127-135
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    • 2002
  • In this study, the preliminary risk assessment for the underground storage tanks(UST) in Chunchon city was implemented using the geographical information system(GIS). The estimation variables, such as the installation year, storage capacity, the distances from streams, and from groundwater pumping wells, were selected to estimate the relative risk levels. The weighting factors were given to all the estimation variables. Cumulative scores were induced by the combination of all the scores of the corresponding variables using the buffering technique and the overlay analysis in ArcView. Using the these process, the relative risk level of each UST was estimated. Some sites in this study are simplified and reduced because the number of useable data are limited or too enormous. Thus the selection of the comprehensive estimation variables and the proper weighting values are required for the future study. The methodology in this study could be served not only for the preliminary risk assessment of UST but also for the selection of the proper location of new and old UST. And, it can be used for the effective management system of UST.

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Research on some of dental hygiene students' stress over the national examination (일부 치위생과 학생의 국가시험 스트레스 연구)

  • Park, Il-Soon;Kim, Hye-Jin
    • Journal of Korean society of Dental Hygiene
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    • v.13 no.4
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    • pp.659-668
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    • 2013
  • Objectives : The purpose of this study is to analyze the causes of stress driven by the national examination and to find out correlation between stress factors and students' general characteristics. Methods : Data were collected from self-reported questionnaires by dental hygiene students in D university in February, 2012. Results : Those having good high school GPAs (p<.05) and high preliminary test scores (p<.01) towards dental hygienist (p<.05). National license examination was the most stressful factor for 54.2% of the students. Much more stressful pressure goes to students of non-scheduled admission (p<.01), students who graduated from vocational high schools(p<.01), students with good high school GPAs (p<.05), and having high preliminary test scores(p<.05). Most of the students tended to bear the burden on national written examination with an average of 4.17. The most difficult subject was oral biology introduction (average 4.52). Oral biology introduction was more stressful to students of early admission, students graduating from vocational high schools (p<.05), students with good high school GPAs (p<.05), and students who had relatively low preliminary test scores (p<.001). Conclusions : It is crucial to reduce stress factors and to develop related programs.

Development Strategy of Orbit Determination System for Korea's Lunar Mission: Lessons from ESA, JAXA, ISRO and CNSA's Experiences

  • Song, Young-Joo;Ahn, Sang-Il;Sim, Eun-Sup
    • Journal of Astronomy and Space Sciences
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    • v.31 no.3
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    • pp.247-264
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    • 2014
  • In this paper, a brief but essential development strategy for the lunar orbit determination system is discussed to prepare for the future Korea's lunar missions. Prior to the discussion of this preliminary development strategy, technical models of foreign agencies for the lunar orbit determination system, tracking networks to measure the orbit, and collaborative efforts to verify system performance are reviewed in detail with a short summary of their lunar mission history. Covered foreign agencies are European Space Agency, Japan Aerospace Exploration Agency, Indian Space Research Organization and China National Space Administration. Based on the lessons from their experiences, the preliminary development strategy for Korea's future lunar orbit determination system is discussed with regard to the core technical issues of dynamic modeling, numerical integration, measurement modeling, estimation method, measurement system as well as appropriate data formatting for the interoperability among foreign agencies. Although only the preliminary development strategy has been discussed through this work, the proposed strategy will aid the Korean astronautical society while on the development phase of the future Korea's own lunar orbit determination system. Also, it is expected that further detailed system requirements or technical development strategies could be designed or established based on the current discussions.

Preliminary Estimation of National Emission Inventory for the Unintentionally Produced Polychlorinated Biphenyls (국내 부산물 다염화비페닐(PCBs) 배출량 예비 평가)

  • Kim Kyoung-Mi;Cho Kyu-Tak;Lee Jee-Yoon;Lee Jee-Eun;Lee Dong-Soo
    • Environmental Analysis Health and Toxicology
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    • v.19 no.2
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    • pp.227-233
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    • 2004
  • The main objectives of this study were to identify from literature review the potential sources and to provide a preliminary national emission inventory for the unintentionally produced polychlorinated biphenyls (PCBs) (i.e., by - product PCBs). In Korea, fuel combustion, waste combustion, thermal industrial processes, and transportation were identified as potential sources of by -product PCB s. According to the availability of the emission factors and/or activity data, emission inventory could be assessed only for fuel combustion, waste combustion, steel industry, non-ferrous industry, and non-metallurgical industry. The total national emission of by-product PCBs was estimated to be 1087kg for the year 2000. The preliminary estimation further indicated that the steel manufacturing was the single dominant emission category, contributing 93% to the total emission. Of the steel manufacturing processes, the contribution of the electric arc furnace was about 80% of the total emission. Due to high uncertainty associated with both the emission factors and activity statistics, the emission estimates in this study are likely to contain significant errors. However, the results of the present work could serve the first step toward future efforts to establish national source and emission inventories of by-product PCBs.

A Study on Improving Usability focused User Interface in the BIM tool sets - Focused on Preliminary-Design and Schematic-Design in Architecture - (BlM 도구의 사용자 인터페이스 개선사항에 관한 연구 - 건축기획과 계획 설계 과정을 중심으로 -)

  • Jeong, Hyeock-Jin
    • Journal of The Korean Digital Architecture Interior Association
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    • v.9 no.1
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    • pp.31-40
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    • 2009
  • This study is intended to suggest methodologies in theory that is dedicated to improve existing features in BlM tool sets and introduce a new horizon for developing new features in the future so that more functionality can be provided to the work process of architect. To be more utilized of BlM tool sets in a useful way, it is important to make sure to program a calculation method used in the design process which is based on the information provided by architect, such as design item with detailed process and transformed parametric information on warranty data. Finding pros and cons in the usability from the well-known 3D modeling applications and taking highly usable UI features from the existing applications, and using a common wording were carried out. Design architect identifies reusable parametric information and then finds an algorithm between each items so that BlM tool sets can contribute to design field in the future. Therefore, the formula has been developed for the items considering business aspects and architecturing size in the preliminary-design, and design aspects in the schematic design with idendifying inputs and outputs that is necessary to become fixed factors.

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Preliminary Analysis on IASCC Sensitivity of Core Shroud in Reactor Pressure Vessel (원자로 노심 쉬라우드의 조사유기응력부식균열 민감도 예비 분석)

  • Kim, Jong-Sung;Park, Chang Je
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.15 no.2
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    • pp.58-63
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    • 2019
  • This paper presents preliminary analysis and results on IASCC sensitivity of a core shroud in the reactor pressure vessel. First, neutron irradiation flux distribution of the reactor internals was calculated by using the Monte Carlo simulation code, MCNP6.1 and the nuclear data library, ENDF/B-VII.1. Second, based on the neutron irradiation flux distribution, temperature and stress distributions of the core shroud during normal operation were determined by performing finite element analysis using the commercial finite element analysis program, ABAQUS, considering irradiation aging-related degradation mechanisms. Last, IASCC sensitivity of the core shroud was assessed by using the IASCC sensitivity definition of EPRI MRP-211 and the finite element analysis results. As a result of the preliminary analysis, it was found that the point at which the maximum IASCC sensitivity is derived varies over operating time, initially moving from the shroud plate located in the center of the core to the top shroud plate-ring connection brace over operating time. In addition, it was concluded that IASCC will not occur on the core shroud even after 60 years of operation (40EFPYs) because the maximum IASCC sensitivity is less than 0.5.

Decision Making of Seismic Performance Management Using Seismic Risk Assessment (지진위험도평가 방법을 이용한 내진성능관리 의사결정)

  • Kim, Dong Joo;Choi, Ji Hye;Kim, Byeong Hwa
    • Journal of the Earthquake Engineering Society of Korea
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    • v.23 no.6
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    • pp.329-339
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    • 2019
  • The strategy for the management of earthquakes is shifting from post recovery to prevention; therefore, seismic performance management requires quantitative predictions of damage and the establishment of strategies for initial responses to earthquakes. Currently, seismic performance evaluation for seismic management in Korea consists of two stages: preliminary evaluation and detailed evaluation. Also, the priority of seismic performance management is determined in accordance with the preliminary evaluation. As a deterministic method, preliminary evaluation quantifies the physical condition and socio-economic importance of a facility by various predetermined indices, and the priority is decided by the relative value of the indices; however, with the deterministic method it is difficult to consider any uncertainty related to the return-year, epicenter, and propagation of seismic energy. Also this method cannot support tasks such as quantitative socio-economic damage and the provision of data for initial responses to earthquakes. Moreover, indirect damage is often greater than direct damage; therefore, a method to quantify damage is needed to enhance accuracy. In this paper, a Seismic Risk Assessment is used to quantify the cost of damage of road facilities in Pohang city and to support decision making.

Development of a scale for the selection criteria of wedding planners (웨딩플래너 선택속성에 관한 척도 개발)

  • Kim, Ha Jeong;Yu, Jihun
    • The Research Journal of the Costume Culture
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    • v.27 no.4
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    • pp.323-335
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    • 2019
  • Identifying the selection criteria of wedding planners, who are the main human resource that contribute to the overall satisfaction level of a wedding's preparation, can produce important data for the wedding industry as it faces a transition period. To develop a scale for wedding planner selection criteria, preliminary items were prepared based on in-depth interviews with an experienced wedding planner group and a comprehensive review of previous studies, such as studies on selection criteria in the wedding industry and service work similar to wedding planners and wedding planner selection criteria. The preliminary items were tested for content validity using a focus group interview, comprising people in the wedding industry, and were refined accordingly. Then, the definitive quantitative questionnaire items were developed after conducting a preliminary survey. The main survey for this study was conducted using the responses of 295 consumers taking an Internet questionnaire. Exploratory factor analysis, Cronbach's alpha, and confirmatory factor analysis were adopted to develop the scale, which was tested for convergent validity and discriminant validity. This study is academically significant in that it developed a selection criteria scale tailored to wedding planners to address an area that has not been covered in previous studies. It is recommended that future studies conduct empirical analyses using the selection criteria developed in this study to compare influential variables that could affect behavior intention.