• Title/Summary/Keyword: Team formation

Search Result 414, Processing Time 0.029 seconds

The Significance of a U.N. Guideline for Long-Term Sustainability of Outer Space Activities (UN 우주활동 장기 지속가능성(LTS) 가이드라인 채택의 의미)

  • Shin, Sangwoo
    • Journal of Aerospace System Engineering
    • /
    • v.13 no.5
    • /
    • pp.49-56
    • /
    • 2019
  • The Long-Term Sustainability (LTS) guidelines have attracted the most attention in the recent formation of international norms of behavior regarding outer space activities. The discussion began at the U.N. COPUOS in 2010. In June 2019, the 21 guidelines were finally adopted. The guidelines include international cooperation to promote and support the observation of the situation of orbiting objects, including space debris, for the purpose of preserving the space environment indefinitely, sharing data and forecasts on space weather, and announcing each country's space policy in accordance with international law. Some guidelines have failed to reach a consensus as the mitigation of space debris is often difficult to separate from space weapons tests. As plans for small satellites and Rendezvous and Proximity Operations have been projected for the future, it is expected that each countries' position on preserving the space environment will become more acute.

A Study on Performance Analysis of a Fish Cage using Air Chamber Structure (대형공기구조물을 이용한 가두리양식장의 성능해석)

  • Choi, Jin;Kim, Soo-Young;Kim, Duk-Eun;Jeong, Seong-Jae
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.43 no.1 s.145
    • /
    • pp.119-127
    • /
    • 2006
  • Recently as a result of excessive development. pollution of the coast and occurrence of a typhoon year after year, fishermen suffer heavy losses in fish farming which is the one of the most important earnings ways. For solution of these problems, we need to go out into the open sea from an inland sea. In this study we suggested new fish cage which makes up for the structural weakness of existing wooden fish cages. It can farm fishes in the open sea of high wave and current with no damages from a typhoon. We substituted TPU(Thermoplastic Polyurethane) air chamber for existing styrofoam flotage which was harmful to the environment and impermanent. We used PE(Polyethylene) pipes for the maintenance of formation and the prevention of buoyancy loss caused by a breakdown of flotage. PE b rackets were designed to combine PE pipes with TPU air-chamber flotage. It has good strength and light weight. As a result of modeling test. it is great in buoyancy, strength and flexibility against wave. Because it can control buoyancy arbitrarily, moreover, we expect that it will reduce damages of a red water by applying it as semi-submerged fish cages.

A Study on the Practical Engineering Eduaction through the Composition of the System for the Mitigation of Insomnia Using Aromatic Substance and Lighting (향기와 조명을 사용한 불면증 완화 시스템 구성의 사례를 통한 공학 교육 실천에 관한 연구)

  • Jeong, Seong-Joo;Lee, Jin-Yu;Seo, Jeong-Eun;Chang, Eun-Young
    • Journal of Practical Engineering Education
    • /
    • v.11 no.1
    • /
    • pp.43-50
    • /
    • 2019
  • A specific example of how to practical engineering education was conducted through the results of the formation of an insomniac mitigation system using aromatic substance and lighting that were conducted over three semesters of a series of curricula related to the composition of graduation works and graduation thesis writing in electronic engineering majors is given as a criteria conditions to certify graduation. Propose the systematic process of the learning achievement process, having learned how to solve problems and to communicate on a team basis. In addition, is analyzed the results of the achievement satisfaction in the major courses conducted with the acquisition of knowledge in engineering, and confirmed that it was included in the level descriptor of engineering issues on the results of the performance measurement and learning in the curriculum.

Processing of Low Tin Zr-1Nb-0.69Sn-0.11Fe Alloy Tubes and Effect of Final Heat Treatment on Their Mechanical and Corrosion Properties (저 Sn 함유 Zr-Nb-Sn-Fe 합금 튜브 제조 및 최종 열처리 온도에 따른 기계적/부식특성 변화)

  • Cho, Nam Chan;Lee, Jong Min;Hong, Sun Ig
    • Korean Journal of Metals and Materials
    • /
    • v.49 no.1
    • /
    • pp.17-24
    • /
    • 2011
  • To investigate the relationship between heat treatment in zirconium alloy tubing process and metallurgical characteristics of Zr-1Nb-0.69Sn-0.11Fe alloy tubes, mechanical and oxidation behaviors of tubes heat treated at different temperatures after the final pilgering were investigated. The stress strain curves exhibited the saturation behaviors in all heat treatment conditions ($460{\sim}600^{\circ}C$) in this study with the onset strain of saturation increased with increase of post-pilgering annealing temperature. The strength fell off rapidly with increasing annealing temperature. The ultimate strength of the low tin Zr-1Nb-0.69Sn-0.11Fe alloy with slightly higher iron and oxygen contents in this study was found to be higher than Zr-1Nb-1Sn-0.1Fe alloy. The oxidation experiments in steam condition revealed that the corrosion resistance of low tin Zr-1Nb-0.69Sn-0.11Fe alloy was better than the Zr-1Nb-1Sn-0.1Fe alloy with a higher Sn content. The weight gain of low tin Zr-1Nb-0.69Sn-0.11Fe alloy tubes gradually increased with the increasing annealing temperature possibly due to the decreased Nb content in the matrix because of the formation of ${\beta}-Nb$ particles.

Stability evaluation of room-and-pillar underground method by 3D numerical analysis model (3차원 수치해석모델을 이용한 주방식 지하공간의 안정성 평가)

  • Byung-Yun, Kang;Sanghyuk, Bang;Choong-Ky, Roh;Dongkwan, Kim
    • Journal of Korean Tunnelling and Underground Space Association
    • /
    • v.25 no.1
    • /
    • pp.1-11
    • /
    • 2023
  • In this study, the stability of the room-and-pillar underground method was investigated using numerical analysis method. In-situ geotechnical investigation was conducted, and a supporting pattern was selected based on the geotechnical investigation data. For the supporting pattern, Type-1, 2, 3 were selected for each ground condition. A 3D numerical analysis model was developed for effective simulation as the room-and-pillar underground method consist of a pillar and room. As a review of numerical analysis, it was confirmed that the crown settlement, convergence, shotcrete and rock bolt were all stable in all supporting patterns. As a result of the analysis by the construction stage, it was confirmed that excessive stress was generated in the room when the construction stage of forming pillar. So, precise construction is required during the actual construction stage of the pillar formation.

Development of a Measuring Tool for Spiritual Care Performance of Hospice Team Members (호스피스 팀원들의 영적 돌봄 수행도 측정 도구 개발)

  • Yoo, Yang-Sook;Han, Sung-Suk;Lee, Sun-Mi;Seo, Min-Jeong;Hong, Jin-Ui
    • Journal of Hospice and Palliative Care
    • /
    • v.9 no.2
    • /
    • pp.86-92
    • /
    • 2006
  • Purpose: This study was conducted to develop a measuring tool for spiritual care performance of hospice team members. The tool may be utilized for providing hospice patients with more systematic and standardized spiritual tares. Methods: The concept and questions of the tool were developed, and then its validity and reliability were tested. For the validity and reliability tests, a self-reported questionnaire comprising 33 questions with 4 point scale ($1{\sim}4$), was developed, and the data were collected from 192 hospice team members from December 2005 to February 2006. Results: Thirty three questions, drafted through literature review and professional consultation, were reviewed by 20 professionals for their validity, were revised and supplemented resulted in the final 33 questions. The questions with a correlation coefficient grater than .30 were selected: all the 33 questions were selected based on this criterion. The reliability coefficient, Cronbarh's ${\alpha}$, was 0.95. The 33 questions were analyzed for factors, and six factors were extracted: relationship formation and communication, encouragement and promotion of spiritual growth, linking with spiritual resources, preparation of death, evaluation and quality control for spiritual intervention, Intervention, and spiritual assessment for intervention. Conclusion: The tool developed in this study includes six factors and has high level of reliability. This tool Will greatly contribute to assess and improve hospice care services, providing systematic and standardized spiritual cares for terminally ill patients and their families.

  • PDF

Examining the Formation of Entrepreneurial Activities through Cognitive Approach (기업가적 활동 형성에 미치는 영향요인: 인지론적 접근)

  • Lee, Chaewon
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
    • /
    • v.12 no.3
    • /
    • pp.65-74
    • /
    • 2017
  • There have been questions how entrepreneurs think, act and why individuals become entrepreneurs. The trait-based explanation of entrepreneurial activities has been main stream. However, the trait-based theory has been criticized because it assumes that entrepreneurial traits are inherited, stable and enduring over time. This research accepts the cognitive theory to see how entrepreneurs learn or accept others' values, how entrepreneurial perceptions of opportunity impact entrepreneurial actions and how individuals acquire the social legitimation of the formation of entrepreneurial activities. In order to capture the attitudes, activities and motivations of people who are involved in entrepreneurial activities, the author uses the GEM Korea 2016 data. The data from the Global Entrepreneurship Monitor(GEM) has been well known for the data to capture individuals early-stage entrepreneurial activities. This paper used the sample from the APS(Adult Population Survey) of the GEM which was completed by a representative sample of two thousand adults in Korea by the qualified survey vendor, with strict procedures and oversight by the GEM central data team. The hypotheses are tested with logit regression analysis to estimate the probability of the influence of perceptual variables such as individual perception in social learning, the opportunity recognition in the environment, and social legitimation in the entrepreneurial activities. Based on the results, individuals tend to have high entrepreneurial activities if individuals have high self-efficacy. Also, the existence of role models around the entrepreneurs encourages the individuals involve in entrepreneurial activities more however the perception of opportunity in the environment is not strongly associated with entrepreneurial activities. The media exposure of successful entrepreneurs is more important than others' perception of entrepreneurs on the desirable career option or respect from communities. This paper can contribute to the cognitive processes, particular perception about oneself, as well as perception which is impacted by a community or a society.

  • PDF

Use of Biosurfactant for the Removal of Organic Pollutants in Soil/Groundwater (바이오 계면활성제에 의한 토양/지하수내 유기성 오염물질 제거)

  • Ko, Seok-Oh;Yoon, Seok-Pyo
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.22 no.2
    • /
    • pp.193-201
    • /
    • 2000
  • Partitioning of hydrophobic organic compounds (HOCs) to a biosurfactant, hydroxypropyl-${\beta}$-cyclodextrin (HPCD), was conducted to evaluate the feasibility of using HPCD to remove HOCs from soil/groundwater. HOC partitioning to HPCD was very fast, with over 95% of the complexation occurring within 10 min. Some influence of solution chemistry and HOC concentration on HOC-HPCD complex formation coefficients was observed. HPCD sorption on soil as quantified by both a fluorescence technique and total organic carbon measurements was negligible, indicating no significant affinity of HPCD for the solid phase. Although the HOC solubilization capability of HPCD was lower than that of synthetic surfactants such as SDS and Tween 80, HPCD can be effective in removing sorbed HOCs from a model subsurface environment, primarily because of its negligible sorption to the solid phase (i.e., all the HPCD added facilitates HOC elution). However, in contrast with conventional surfactants, HPCD becomes relatively less effective for HOC partitioning with increasing HOC size and hydrophobicity. Therefore, comparisons between HPCD and synthetic surfactants for enhanced remediation applications must consider the specific HOC(s) present and the potential for surfactant material losses to the solid phase, as well as other more generally recognized considerations such as material costs and potential toxicological effects.

  • PDF

Effects of Vernalization, Temperature, and Soil Drying Periods on the Growth and Yield of Chinese Cabbage (춘화, 온도와 토양건조 기간에 따른 배추의 생장 및 수량)

  • Lee, Sang Gyu;Lee, Hee Ju;Kim, Sung Kyeom;Choi, Chang Sun;Park, Sung Tae;Jang, Yoon Ah;Do, Kyung Ran
    • Horticultural Science & Technology
    • /
    • v.33 no.6
    • /
    • pp.820-828
    • /
    • 2015
  • This study was carried out to determine the effects of vernalization, temperature, and soil water deficit (SD) on mesophyll cells, growth, and yield of Chinese cabbage (Brassica campestris L). The palisade parenchyma and spongy tissues of Chinese cabbage were observed under full irrigation and two weeks of SD treatment. These cells were severely collapsed by four weeks SD treatment. The SD treatment had the greatest influence on the growth of Chinese cabbage among the tested treatment factors (vernalization, temperature, and SD), growth significantly decreased by severe drought treatment (four weeks SD treatment). In addition, the relative growth rate, unit leaf rate, leaf area ratio, specific leaf area, and leaf weight ratio were significantly affected by SD treatment; however, other individual factors and their combined treatments did not influence the analyzed growth parameters. The yield under vernalization after high temperature and full irrigation treatments was 3,056 kg/10 a, which was the greatest among all the tested treatments, while four-week SD treatment significantly reduced the yield. Head formation of Chinese cabbage was not altered under SD treatment, and vernalization treatments did not induce bolting. Our results indicated that collapsing mesophyll cells and reduced growth and yield were induced by SD treatment. Thus we suggest that optimal irrigation system should be install to avoid or overcome crippling drought conditions in the open field.

Noise Prediction of Korea High Speed Train (KHST) and Specification of Sub-components (한국형 고속전철 차량소음 예측 및 부품 소음관리방안)

  • ;;;H.W. Thrane
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.12 no.10
    • /
    • pp.758-765
    • /
    • 2002
  • KITECH and ODS performed a study of internal and external noise prediction of the Korean high speed prototype test train(HSR 350X). The object of this study was 3 kinds of cars, trailer car(TT2), motorized car(TMI ) and power car(TPI) and the predicted noise was for the two different driving speeds in free field and tunnel conditions. Data of carbody design and noise sources were delivered from manufactures. Some of noise sources which were not available in the project team, were chosen by experiences of ODS. Internal noise level of each car was predicted for two cases i.e, at 300 km/h and 350 km/h. In addition sound transmission path and dominant noise sources were also investigated for each section of the car, which is circular shell typed part of whole carbody. In case of TT2, the dominating sound transmission path is the (floor in terms of structure-borne noise and air-borne noise. The main noise sources are structure-borne noise from the yaw-damper and air-borne noise from the wheel/rail contact, whereas the dominating sound transmission path of TMI are floor and sidewall below the window in terms of structure-borne noise. The main noise sources of TMI are structure-borne noise from motor/gear unit and the yaw-damper in the free field, and air-borne noise from the wheel/rail contact and structure-borne noise from motor/gear unit in the tunnel. Through the external noise prediction for the KHST test train formation, the noise form the wheel/rail contact is estimated as one of the major sources. In addition, the noise specification of sub-component was proposed for managing each sub-surpplier to reach the KHST noise requirement. The specification provide the sound power of machinery part and transmission loss of component of carbody structure. The predicted noise level in each case exceeded the required limit. Through this study, the noise characteristics of the test train were investigated by simulation, and then the actual test will be performed in near future. Both measured and calculated data will be compared and further work for noise reduction will be continued.