• Journal of the Earthquake Engineering Society of Korea
• /
• v.3 no.4
• /
• pp.1-10
• /
• 1999

Free-field ground motion during earthquake is significantly affected by the local site conditions and it is essential for the seismic design to perform the site specific ground response analysis. In this paper, the procedures of site specific ground response analysis were suggested based on the Korean seismic guideline and the review of state of the art technologies. The concept of ground response analysis was introduced, and the techniques of obtaining soil data for one dimensional equivalent linear analysis which include site investigation planning, field and laboratory testing techniques, deformational characteristics of soils at small to large strains, and site characterization techniques combining field and laboratory test results, were suggested. Finally, the case study was performed at Inchon area following the suggested procedure.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.3
• /
• pp.455-463
• /
• 2015

This study investigated the effects of low-dose electron beam irradiation treatment on the physicochemical and sensorial properties of imported navel oranges during storage at $20^{\circ}C$ for 12 days. The samples were irradiated at doses of 0.2, 0.4, 0.6, 0.8, and 1.0 kGy, after which changes in color value, hardness, Brix/acid ratio, total sugar contents, reducing sugar contents, vitamin C contents, and sensory evaluation were investigated. There were no significant differences between non-irradiated and irradiated samples in terms of color value, Brix/acid ratio, total sugar contents, total reducing sugar contents, and vitamin C contents. Hardness of irradiated samples significantly decreased in the early storage period in an irradiation dose-independent manner, and the difference between non-irradiated and irradiated samples decreased again at the end of storage. For the sensory evaluation, there was no significant difference between non-irradiated and irradiated samples up to 0.6 kGy, and all sensory item scores decreased at the end of the storage period regardless of irradiation. These results suggest that electron beam irradiation below 0.6 kGy does not affect physicochemical and sensory properties during storage at $20^{\circ}C$. Thus, electron beam irradiation up to 0.6 kGy applied to imported navel oranges is the optimum dose for minimizing quality changes and disinfestation treatment.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2007.05a
• /
• pp.126-127
• /
• 2007

본 연구는 Microwave를 이용하여 활성탄의 재생특성을 파악하는데 목적을 두었다. Microwave의 조사횟수를 달리하였을때 활성탄의 특성 변화분석하였다. BET 분석결과 조사 후 분석 값이 조사 후 분석 값보다 떨어짐을 알 수 있다. 이는 MW를 조사함으로써 활성탄의 온도가 상승이 되고 이로 인해 기공의 파괴가 있음을 알 수 있다. 각 물질별로 20번씩 조사 하여서 나타난 결과를 보면 비표면적이 각각 8.2%(A), 5.68%(B), 0.38%(C) 줄었다. 활성탄 C의 경우는 조사 후 감소된 면적이 가장 적었는데 이는 먼저 제조하였던 활성탄의 경우는 활성탄의 성분이 제기능이 못할 정도로 소성을 하였거나 탄소성분의 변질이 있었음을 알 수 있다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.358-363
• /
• 2008

도시 광역화와 인구의 집중에 따라서, 도시 거주민의 삶의 질 향상을 위해서는 많은 기반이 필요하다. 이중에서 깨끗한 위생 환경을 위해서 용수의 공급 및 하수의 처리는 매우 중요한 문제라고 할 수 있다. 이를 위하여 많은 조사와 보수가 이루어지고 있지만, 관로의 내면을 조사하는 다양한 기법은 활발하게 이루어지고 있는 반면, 도로의 침하나, 관로 내부로의 침입수 또는 침출수 등을 유발할 수 있는 관로 배면의 상태를 조사하는 기법은 아직 미비한 상태라고 할 수 있다. 따라서 본 연구에서는 이러한 관로의 배면에 대한 정보를 취득하기 위하여 매질을 통과하여 정보를 취득할 수 있는 지중탐사레이더(GPR)을 이용하여 관로의 배면 상태를 탐사하기 위한 기본 반사 특성을 조사하고 이를 기준으로 실제대상물의 반사 특성을 조사 분석하여 관로 배면 지반의 특성을 조사, 평가하고자 한다.

• The Journal of the Acoustical Society of Korea
• /
• v.17 no.6
• /
• pp.23-28
• /
• 1998

고분자 압전 필름인 PVDF를 이용하여 단일막과 이층막의 초음파 변환기를 제작하 여 임펄스 응답특성을 이론식에서 계산하여 실험적으로 확인하여 보았다. 또한 RF 펄스를 이용하여 초음파 변환기의 다층막에 따른 주파수 특성을 조사하였다. 그 결과 임펄스 응답 특성은 이론식과 잘 일치하였으며, 단일막의 변환기가 이층막에 비하여 지속시간이 짧은 펄 스를 나타내었다. RF펄스에 대한 주파수특성은 이층막의 변환기가 단일막에 비하여 광대역 의 특성을 나타냄을 알 수 있었다.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.163-165
• /
• 2002

LDD구조를 가진 LDMOS 전력소자의 LDD영역과 채널영역변화에 의한 전기적 특성을 비교 조사하였다. MEDICI 시뮬레이션 tool을 이용하여 hot-carrier전류의 특성, ON 저항의 변화, breakdown 전압의 특성과 switch transient 특성을 조사하였다. Gate-drain 사이의 불순물도핑 영역 및 농도에 따른 소자의 특성해석은 LDD구조를 가진 LDMOS가 hot-carrier resistance 및 전력소모 관점에서 우수한 특성을 나타낼 것으로 사료된다

• Survey Research
• /
• v.1 no.1
• /
• pp.135-148
• /
• 2000

• Journal of the Microelectronics and Packaging Society
• /
• v.30 no.3
• /
• pp.56-63
• /
• 2023

In this paper, we studied the effect of electron beam irradiation on sol-gel indium-gallium-zinc oxide (IGZO) thin films under air and nitrogen atmosphere and carried out the electrical characterization of the s ol-gel IGZO thin film transistors (TFTs). To investigate the optical properties, crystalline structure and chemical state of the sol-gel IGZO thin films after electron beam irradiation, UV-Visible spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were carried out. The sol-gel IGZO thin films exhibited over 80% transmittance in the visible range. The XRD analysis confirmed the amorphous nature of the sol-gel IGZO films regardless of electron beam irradiation. When electron beam irradiation was conducted in a nitrogen (N₂) atmosphere, we observed an increased proportion of peaks related to M-O bonding contributed to the improved quality of the thin films. Sol-gel IGZO TFTs subjected to electron beam exposure in a nitrogen atmosphere exhibited enhanced electrical characteristics in terms of on/off ratio and electron mobility. In addition, the electrical parameters of the transistor (on/off ratio, threshold voltage, electron mobility, subthreshold swing) remained relatively stable over time, indicating that the electron beam exposure process in a nitrogen atmosphere could enhance the reliability of IGZO-based thin-film transistors in the fabrication of sol-gel processed TFTs.

• Survey Research
• /
• v.10 no.2
• /
• pp.115-136
• /
• 2009

This paper examines the past tendencies of survey study on military organizations and explores the directions and alternatives of research study based on one of the main military characteristics of rank structure. Military survey study has limitations in confirming the credibility of the research results and in supporting implications on the diverse subjects due to the constraining research environment in the military. This study deduced survey designs and analytic methods fit for the research objective upon multidimensionally grasping the characteristics of the hierarchical rank structure which influences the survey process aid its result crucially. It proposes that the future direction of military survey study is to elaborate research method and multidimensionalize analytic methodology. More specifically. this paper insists that it is necessary to design method and process of the survey delicately and to develop analytic methodology which can analyze diverse factors.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.28 no.3
• /
• pp.241-271
• /
• 2017

The present study investigates domestic and foreign cases of library specialization, and specialization policies, areas, and effects in order to delineate future directions for research on the subject. The results of the study indicated that library specialization policies have been implemented in Korea and other countries. In Korea, a short-term policy was implemented in 1998, designating 13 special libraries, nine of which are currently in operation. Regarding types and directions of specialization, specialization of collections was found in many cases. Regional representative libraries were also found to have designated specific subjects they focus individually in terms of collections and services while providing services in subject areas. The future directions include research in qualifications and competence of professionals employed in special libraries, and in user satisfaction and needs to inform libraries' efforts for specialization.