• Title/Summary/Keyword: Research Directions

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Slope Rotatability Over All Directions and Average Slope Variance in Spherical Surface

  • Sim, Jung-Wook;Oh, Mi-Ra
    • Communications for Statistical Applications and Methods
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    • v.7 no.2
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    • pp.415-426
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    • 2000
  • Hader and Park (1978) introduced the idea of slope rotatability, and Park (1987) introduced the concept of slope rotatability over all directions, and gave necessary and sufficient conditions. Park and Kim (1992) proposed a measure that represent the extent of slope rotatability for a given response surface design. Kim (1993) proposed a measure that represent the extent of slope rotatavility over all directions. In this paper, we embodied the measure of slope rotatability over all directions. Examples of applying this measure to some response surface designs are also given. In this response surface design of slope rotatavility over all directions, we obtain the mean slope variances on the spherical surface to select better experimental design varying the number of center points and radius.

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A Weighted Points Registration Method to Analyze Dimensional Errors Occurring during Shipbuilding Process (선박 건조 과정에서 발생하는 치수 오차 분석을 위한 가중 포인트 정합 방법)

  • Kwon, Kiyoun
    • Korean Journal of Computational Design and Engineering
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    • v.21 no.2
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    • pp.151-158
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    • 2016
  • It is important to analyze dimensional errors occurring during shipbuilding process. A ship is constructed by assembling blocks and installing outfits in assembled ship structure. Blocks and outfits have a main direction that has greater importance than other directions from the view point of dimensional error. Therefore, a main direction should have a greater weighting factor than other directions in order to achieve meaningful inspection results. In this paper, a modified point registration method based on iterative closest point (ICP) is proposed. In this method, a user determines one or two main directions among x, y, and z directions, and then each main direction is made to have a greater weighting factor than other directions. For points registration, mapping between measured points and design points are performed by the modified ICP in which weighting factor assigned to each main direction is considered.

Measurement and Control of Hazardous PAHs Reaction Products (위해성 이차 PAHs 성분 측정 및 관리 방안)

  • Lee, Ji Yi;Hong, Ji Hyung;Jung, Chang Hoon;Kim, Yong Pyo
    • Particle and aerosol research
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    • v.9 no.2
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    • pp.111-125
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    • 2013
  • Among the hazardous air pollutions(HAPs), characteristics of secondary organic aerosols are not well understood. In this study, the current state for the measurement and analysis of representative secondary PAHs such as oxy-PAHs and nitro-PAHs are presented with the discussion of their toxicity. Also, further research directions for the secondary PAHs are suggested. It was found that the chemical reaction mechanisms and products of PAHs in the air are poorly identified and their toxicities are not well studied. Moreover ambient concentrations of those secondary PAHs are not well documented. Sampling methodologies of those secondary PAHs are similar with PAHs but the analytical protocols for those secondary PAHs are more complicated than PAHs. Future management directions are suggested along with future research directions.

Underwater Laser Cutting of Thick Stainless Steel in Various Cutting Directions for Application to Nuclear Decommissioning

  • Shin, Jae Sung;Oh, Seong Y.;Park, Seung-Kyu;Kim, Taek-Soo;Park, Hyunmin;Lee, Jonghwan
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.19 no.3
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    • pp.279-287
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    • 2021
  • For application in nuclear decommissioning, underwater laser cutting studies were conducted on thick stainless-steel plates for various cutting directions using a 6 kW fiber laser. For cutting along the horizontal direction with horizontal laser irradiation, the maximum cutting speed was 110 mm·min-1 for a 48 mm thick stainless-steel plate. For cutting along the vertical direction with horizontal laser irradiation, a maximum speed of 120 mm·min-1 was obtained for the same thickness, which confirmed that the cutting performance was similar but slightly better. Moreover, when cutting with vertically downward laser irradiation, the maximum cutting speed was 120 mm·min-1 for a plate of the same thickness. Thus, the cutting performance for vertical irradiation was nearly identical to that for horizontal irradiation. In conclusion, it was possible to cut thick stainless-steel plates regardless of the laser irradiation and cutting directions, although the assist gas rose up due to buoyancy. These observations are expected to benefit laser cutting procedures during the actual dismantling of nuclear facilities.

An Estimating Space Program of Technical High School for Future Educational Curriculum (전문교과 교육과정에 대응하기 위한 공업계고등학교 공간규모 산정에 관한 연구)

  • Lee, Sang-Min
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.7 no.2
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    • pp.12-29
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    • 2008
  • The problem should be approached in terms of recovering essential functions of technical high school and identification to supply stable and quality human resources in technical sector. An adequate space programming for technical high school is needed to educate effective skills and techniques. Considering the education directions of vocational high school, the article covers principals of technical school's construction plan and directions and, based on this, suggest the way of estimating the scale in construction plan of technical school. Through this research, systematic and reasonable space planning can be possible. The range of this research is based on development directions of society and education and an objective standard in a newly reformed the 7th Stage of Education. In addition, the research is limited to technical high school among kinds of vocational high school. The purpose is to redefine the role of technical school that face identification crisis currently, comparing to the past, and to suggest a more effective space planning. The research limits the space to classes for specialized subjects, a core space for education in technical school among diverse spaces.

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Determination of Driving Rain Index by Using Hourly Weather Data for Developing a Good Design of Wooden Buildings

  • Ra, Jong Bum
    • Journal of the Korean Wood Science and Technology
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    • v.46 no.6
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    • pp.627-636
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    • 2018
  • This research was performed to supplement the previous research about the driving rain index (DRI) for Korea determined by using daily weather data for 30 years. The average annual driving rain index (AADRI) was calculated from the hourly weather data, and the magnitude of DRI was investigated according to wind directions. The hourly climate data were obtained from the Korea Meteorological Administration (KMA) for the period 2009 to 2017. Of 82 locations investigated, seven were classified into regions where the level of exposure of walls to rain was high. The result showed quite a difference from the previous results, in which no high exposure regions were observed. Since the hourly-based and the daily-based annual driving rain index (ADRI) values showed only a slight difference, the result may be explained by the length of the periods used in both studies. The change of DRI according to wind directions showed that there was a certain range of wind directions in which driving rain easily approached building walls. It suggests that the consideration of wind directions with high DRI would be useful to develop a good design of wooden buildings from the point of wood preservation and maintenance.

Groundwater Management Pradigm Shift and Policy Directions for Integrated Water Management in Korea (통합 물관리를 위한 우리나라 지하수 관리 패러다임 전환과 정책방향)

  • Hyun, Yunjung;Han, Hye Jin
    • Journal of Soil and Groundwater Environment
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    • v.26 no.6
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    • pp.176-185
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    • 2021
  • This paper aims to develop a new paradigm for groundwater management which is compatible with integrated water management policies in Korea. Three key roles of groundwater are defined for addressing water cycle distortion, high water stress, water quality degradation, aquatic ecosystems deterioration, and water-related hazards. Firstly, groundwater plays an important role in contributing soundness of water cycle as a component of water cycle. Secondly, it is a local water resource to ensure water supply sustainability. Thirdly, groundwater is an essential water resource for drought and emergencies. In order to support the groundwater roles, we propose a paradigm shift for groundwater management and policy directions towards integrated water management. The new paradigm consists of managements for sound water cycle on a watershed scale and groundwater environment(quantity, quality, and groundwater dependent ecosystems) managements for both human and nature. A prospective management also constitutes the new paradigm. In addition, this paper proposes four policy directions in groundwater management. The policies emphasize the integrated management of groundwater and surface water, management of groundwater environment(quantity, quality, and groundwater dependent ecosystems), management of groundwater uses for water sustainability and security, and enhancement of groundwater publicity.

A Survey of Security and Privacy Challenges in Cloud Computing: Solutions and Future Directions

  • Liu, Yuhong;Sun, Yan Lindsay;Ryoo, Jungwoo;Rizvi, Syed;Vasilakos, Athanasios V.
    • Journal of Computing Science and Engineering
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    • v.9 no.3
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    • pp.119-133
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    • 2015
  • While cloud computing is gaining popularity, diverse security and privacy issues are emerging that hinder the rapid adoption of this new computing paradigm. And the development of defensive solutions is lagging behind. To ensure a secure and trustworthy cloud environment it is essential to identify the limitations of existing solutions and envision directions for future research. In this paper, we have surveyed critical security and privacy challenges in cloud computing, categorized diverse existing solutions, compared their strengths and limitations, and envisioned future research directions.

Directions for Revision of Rural Development Law (농촌진흥법 개정방향)

  • Lee, Min
    • Journal of Agricultural Extension & Community Development
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    • v.6 no.2
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    • pp.53-74
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    • 1999
  • This study aimed at exploring new directions for revision of the Rural Development Law. Research and development for environmentally friendly agricultural technologies and localization of the extension offices and staffs were some of the important challenges to agricultural extension services in Korea. The study suggested new directions for revision of the Rural Development Law should consider new development and environmental concerns of agricultural sciences, and needs of farmers, local and central government. Some of major focus of the revised Rural Development Law should include the following; 1) Rural development programs should cover extended areas of newly developed concerns and target groups, 2) County and city administration should provide proper administrative and financial support for local agricultural extension center. 3) Areas for agricultural research and development should be extended to meet the needs of newly developed technologies and sustainable environment system at local level, 4) Monitoring and evaluation of extension efforts should be performed annually to support financially and to strengthen proper systematic linkage between national and local extension services.

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