• Title/Summary/Keyword: working face

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Research on 3 Dimensional Air Flow Simulation in Underground Workings (지하 작업장내 3차원 기류거동 예측기술 연구)

  • 김복윤;한공창
    • Tunnel and Underground Space
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    • v.6 no.3
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    • pp.250-259
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    • 1996
  • According to the wide application of diesel equipments in tunneling faces, the air contamination by various toxic gases and carcinogenic diesel particulate matter becomes a serious problem these days. For taking a scientific measures to solve the problem, the way to simulate 3 dimensional flow movement of the working sites is required. In this paper, the newly developed simulation program(3D-FLOW) and the results of a simulation on a model tunneling workings using diesel equipments are introduced. In case of typical model of tunneling face, the gas concentration of human height is about one third of roof concentration and right side half of the tunnel shows better environment than left half. NOx concentration of workings can be estimated about 0.45ppm which is much lower than permissible level(5 ppm).

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A Study on the Press Drawing of a Sheet Metal Part with Holes on the Slope (경사면에 구멍이 있는 판재 부품의 프레스 드로잉에 관한 연구)

  • Lee, Ji-Ho;Jun, Cha-Soo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.10
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    • pp.50-55
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    • 2021
  • In this study, to create circular holes on an inclined conic face, we developed a novel process of vertical piercing on the plane before drawing, instead of applying an expensive cam-piercing method. The pierced holes are deformed during the drawing, and their shapes are affected by the size of the center hole. Using the Abaqus CAE program, the deformation tendency of the holes, according to the diameter of the center hole, was identified, and the diameter for securing the roundness of the side holes were determined through actual experiments. The developed process was successfully applied to mass production of the part, and a cost reduction is expected.

A Study on the Development of Sustainable Operating Direction of Library after Corona: Focusing on the Implementation Performance and Implementation Plan of the 3rd Library Development Plan (공공도서관의 코로나 이후 지속가능한 운영 방향 모색 연구 - 제3차 도서관발전종합계획의 추진실적 및 시행계획 중심으로 -)

  • Noh, Younghee;Ro, Ji-Yoon
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.32 no.3
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    • pp.45-65
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    • 2021
  • How are real libraries affected and what are they planning and working on in the current coronavirus era? Based on these questions, the purpose of this study was to analyze the Corona-related trends based on the 2020 implementation plan of the Library Development Comprehensive Plan and the 2021 implementation plan, and to analyze the impact and changes of the libraries in the city and the direction of corona response. The problems in the 2020 municipal libraries are largely attributed to the closure or curtailment of libraries due to the epidemic of coronavirus, budget cuts and budget limits due to coronavirus, declining users' interest and participation, infrastructure limits due to rapid service changes and operational limitations. Furthermore, the improvement measures and future plans could be divided into 1) development and provision of non-face-to-face programs; 2) development and provision of online-based services; 4) expansion of budget for response to demand; 5) provision of space against corona; and other response directions. In addition, in order to systematically cope with coronavirus in the future, it is expected that first, hybrid-type programs and services, second, infrastructure for online and non-face-to-face services, and third, budget utilization flexibility will be required.

Numerical analysis of water flow characteristics after inrushing from the tunnel floor in process of karst tunnel excavation

  • Li, S.C.;Wu, J.;Xu, Z.H.;Li, L.P.;Huang, X.;Xue, Y.G.;Wang, Z.C.
    • Geomechanics and Engineering
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    • v.10 no.4
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    • pp.471-526
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    • 2016
  • In order to investigate water flow characteristics after inrushing in process of karst tunnel excavation, numerical simulations for five case studies of water inrush from the tunnel floor are carried out by using the FLUENT software on the background of Qiyueshan high risk karst tunnel. Firstly, the velocity-distance curves and pressure-distance curves are drawn by selecting a series of probing lines in a plane. Then, the variation characteristics of velocity and pressure are analyzed and the respective optimized escape routes are made. Finally, water flow characteristics after inrushing from the tunnel floor are discussed and summarized by comparing case studies under the conditions of different water-inrush positions and excavation situations. The results show that: (1) Tunnel constructors should first move to the tunnel side wall and then escape quickly when water inrush happens. (2) Tunnel constructors must not stay at the intersection area of the cross passage and tunnels when escaping. (3) When water inrush from floor happens in the left tunnel, if tunnel constructors meet the cross passage during escaping, they should pass through it rapidly, turn to the right tunnel and run to the entrance. (4) When water inrush from floor happens in the left tunnel, if there is not enough time to escape, tunnel constructors can run to the trolley and other equipment in the vicinity of the right tunnel working face. In addition, some rescuing equipment can be set up at the high location of the cross passage. (5) When water inrush from floor happens in the cross passage, tunnel constructors should move to the tunnel side wall quickly, turn to the tunnel without water inrush and run to the entrance. (6) When water inrush from floor happens in the cross passage, if there is not enough time to escape, tunnel constructors can run to the trolley and other equipment near by the left or the right tunnel working face. The results are of important practical significance and engineering value to ensure the safety of tunnel construction.

A Study on the Improvement of Public Library Workflow Using Process Innovation (프로세스 이노베이션을 활용한 공공도서관 업무 프로세스 개선에 관한 연구)

  • Noh, Dong-Jo;Kim, Young-Mi;Oh, Dong-Geun
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.28 no.4
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    • pp.393-413
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    • 2017
  • This study will explore the possibility of applying process innovation as a public library for business innovation. In order to do this, the study defines the concept of process innovation through the literature review. According to survey and focus group interviews with librarians working for public libraries, this study will organize work done at libraries into the following categories: acquisition, resource management, user management, user services, programs, volunteer management, marketing, library computerization system, facility management, general affairs and statistical management. In addition, through face-to-face surveys with librarians working for public libraries it is confirmed that there are issues within acquisition, user management, and applied process innovation. In response to these issues a new process has been developed. Using this new approach, book contract procedure and requests for book related work could be improved and optimized. In the user management section, the study analyzes the requirements and subscription procedures for members through a website survey of 30 public libraries in the United States and then provides an improved system through process analysis of the membership process of Korean public libraries. It is expected that the new system will contribute to improvements in user satisfaction as well as improvements in library workflow.

Perception Gap between Preceptors and Pharmacy Students on Introductory Pharmacy Practice Education in Community Pharmacy Practice Setting (지역약국 필수실무실습에 관한 프리셉터와 학생의 인식 비교)

  • Park, Ji Young;Jin, Hye Kyung;Kang, Ji Eun;Rhie, Sandy
    • Korean Journal of Clinical Pharmacy
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    • v.25 no.2
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    • pp.102-110
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    • 2015
  • Objective: This study was to investigate the perception gap between preceptors and pharmacy students on community pharmacy experiential education. Methods: The online survey was performed for 55 preceptors and 215 pharmacy students separately from April 1 to April 30, 2014. The preceptors were who completed community pharmacy practice experience at least a session and the students were who involved in community pharmacy practice for more than 21 days. The questionnaires were prepared based on the lesson contents guideline of Introductory Pharmacy Practice Education of Community Pharmacy by Korea Association of Pharmacy Education. The survey questions were consisted with demographic characteristics, evaluation of student and preceptors, benefits and disadvantages of pharmacy practice for both groups. Results: A total of 27 (49.1%) preceptors and 103 (47.9%) pharmacy students responded to the survey questionnaires. Preceptors indicated that students lacked face-to-face communication ability with patients, caregivers, and physicians. One of the Benefits of participating in pharmacy practice education as a preceptor included the improvement of self-esteem (70.37%). Disadvantages were identified as workload burden due to teaching and preceptor responsibilities at the same time. All students responded that benefits of experiencing pharmacy practice education were helping them determine their career, and they would consider working in community pharmacies (68.93%). However, handling over-the-counter drugs and communicating with doctors or nurses were identified as barriers. In addition, preceptors and pharmacy students expressed necessity of the standard text books and curriculums. Conclusion: This study identified the perception gap on community pharmacy experiential education between preceptors and pharmacy students. For the successful implementation of pharmacy practice experience, the effective and appropriate methods should be developed.

Work performance and calling as factors influencing job satisfaction among nurse midwives working in the delivery room (분만실에 근무하는 조산사의 직무수행과 소명의식이 직무만족도에 미치는 영향)

  • Jung, Geum Ah;Kim, Moon Jeong
    • Women's Health Nursing
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    • v.26 no.1
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    • pp.10-18
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    • 2020
  • Purpose: The purpose of this study was to investigate work performance and calling as determinants of job satisfaction among nurse midwives. Methods: The participants of this study were registered nurse midwives who had worked in the delivery room for more than 6 months. Data were collected by face-to-face interviews, postal mail, and mobile devices. Subjects completed self-report questionnaires from July to August 2017. The dataset was analyzed using descriptive statistics, the independent t-test, analysis of variance, the Pearson correlation coefficient, and multiple regression. Results: The mean score for job satisfaction was 3.42±0.45. Among the sub-factors, income had the lowest score (2.67±0.72) and management of delivery had the highest score (3.81±0.66). Job satisfaction was significantly different according to marital status (t=2.25, p=.028), residential area (t=2.43, p=.016), and cause of job satisfaction (F=4.54, p=.012). Job satisfaction showed a significant positive correlation with work performance (r=.29, p<.001) and calling (r=.57, p<.001). The correlation between work performance and calling was also positive and statistically significant (r=.32, p<.001). Purpose and meaning (β=.48, p<.001) and marital status (β=-.15, p=.025) significantly influenced job satisfaction. The model developed in this study explained 45% of variation in job satisfaction. Conclusion: Nurse midwives' job satisfaction may be enhanced by entrusting them with professional roles and tasks. Above all, it is necessary to develop and provide programs that help nurse midwives connect their jobs with the meaning and purpose of their lives.

Case study of the mining-induced stress and fracture network evolution in longwall top coal caving

  • Li, Cong;Xie, Jing;He, Zhiqiang;Deng, Guangdi;Yang, Bengao;Yang, Mingqing
    • Geomechanics and Engineering
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    • v.22 no.2
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    • pp.133-142
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    • 2020
  • The evolution of the mining-induced fracture network formed during longwall top coal caving (LTCC) has a great influence on the gas drainage, roof control, top coal recovery ratio and engineering safety of aquifers. To reveal the evolution of the mining-induced stress and fracture network formed during LTCC, the fracture network in front of the working face was observed by borehole video experiments. A discrete element model was established by the universal discrete element code (UDEC) to explore the local stress distribution. The regression relationship between the fractal dimension of the fracture network and mining stress was established. The results revealed the following: (1) The mining disturbance had the most severe impact on the borehole depth range between approximately 10 m and 25 m. (2) The distribution of fractures was related to the lithology and its integrity. The coal seam was mainly microfractures, which formed a complex fracture network. The hard rock stratum was mainly included longitudinal cracks and separated fissures. (3) Through a numerical simulation, the stress distribution in front of the mining face and the development of the fracturing of the overlying rock were obtained. There was a quadratic relationship between the fractal dimension of the fractures and the mining stress. The results obtained herein will provide a reference for engineering projects under similar geological conditions.

Design Improvement of Mechanical Transmission for Tracked Small Agricultural Transporters through Gear Strength Analysis

  • Kim, Hong-Gon;Jo, Yeon-Ju;Kim, Chul-Soo;Han, Yong-Ho;Kim, Dae-Cheol
    • Journal of Biosystems Engineering
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    • v.41 no.1
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    • pp.1-11
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    • 2016
  • Purpose: The gear strength of a new mechanical transmission designed to increase the loading weight of small 4.8 kW tracked agricultural transporters was analyzed. Design improvements to increase the gear strength and reduce the gear weight were proposed after examining the parameters. Methods: Sixteen operators from three regions were surveyed to obtain the usage profile of small 4.8 kW transporters. Gear strength was evaluated by calculating contact stress and tooth root stress using commercial software following ISO 6336. Results: From the strength calculation for each gear pair, contact stress smaller than tooth root stresses were produced in all gear pairs. The safety factors in most cases exceeded 1.0, except in the case of gear pair II in group II. The design life of the transporter using gear pair II in group II was 42% under harsh conditions-thus, this design life needs improvement. A robust design was proposed by examining the relevant parameters (face width and profile shift coefficient) to increase the design life of the transporter. In addition, a lightweight design for gear pair I in group II that was considered overdesigned was proposed by examining the face width to reduce the weight of the drive gear by 42% and that of the driven gear by 30%. Conclusions: The Safety factor for the design life was examined through a gear strength analysis. After examining the relevant parameters, conditions for strength improvement were proposed to increase design life or adjust overdesigned gear. However, load conditions differ depending on the working conditions or user's preferences; therefore, it is necessary to conduct further studies in various regions.

Utilization of IT Survey Method in the National Statistics Survey (국가통계조사에서의 IT조사방법 활용에 대한 연구)

  • Shim, Kyu-Ho;Lee, Eui-Kyoo
    • Survey Research
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    • v.10 no.2
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    • pp.137-161
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    • 2009
  • Survey environment has recently been changed along with its bad conditions. Surveyors feel difficult to meet respondents because the number of one person-household and working-together-household has rapidly increased. With a growing awareness of protecting personal information, respondents no longer want to response to a questionnaire. To get responses form an increasing number of non-response houses and respondents who are difficult to meet, Korea National Statistical Office(KNSO) has changed its survey methods and thus introduced new survey methods, free from face-to-face interviews. A telephone interview has officially been allowed for some reasonable situations and it shows a tendency that the trend of interviewing method is moving toward Internet survey. This paper focuses on how survey methods should be changed with the use of IT in response to changes in the survey environment. Survey methods combined with IT have many excellent advantages, Korea has been an enviable World IT contest for a long time. If Korea can apply such an advanced IT environment to survey methods successfully, it will make a great contribution toward improving the survey quality. This paper also reviews which survey method is most appropriate for National Statistics as the survey environment has changed.

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