• Applied Chemistry for Engineering
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• v.16 no.4
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• pp.527-532
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• 2005

Ionic polymer metal composites (IPMC) are soft polymeric smart materials having large displacement at low voltage in air and water. The polymeric electrolyte actuator consists of a thin and porous membrane and metal electrodes plated on both faces, in impregnation electro-plating method. The response and actuation of actuator are governed. Among many factors governing the activation and response of IPMC actuator, the surface electrode plays an important role. In this study, the well-designed modification of electrode surface was carried out in order to improve the chemical stability well as electromechanical characteristics of the IPMC actuator. We employed Ion Beam Assisted Deposition (IBAD) method to prepare the topologically homogeneous thin surface electrode. After roughing the surface of Nafion membrane in order to get a larger surface area, the IPMC was prepared by impregnation for electro-plating and re- coating on the surface through traditional chemical deposition, followed by an additional surface treatment with high conductive metals with IBAD. It was observed that our IPMC specimen shows the enhanced surface electrical properties as well as the improved actuation and response characteristics under applied electric field.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.3
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• pp.286-294
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• 2009

Statement of problem: In spite of increasing dental treatment for the disabled, there was no collected data on prosthodontic treatment status and dentists' perceptions in Korea. Purpose: The purpose of this study was to research the dentists' perceptions about current prosthodontic treatment status for the disabled in Korea and to suggest public health policies for the disabled. Material and methods: Total of 68 dentists who have regularly treated the disabled were asked to fill questionnaires regarding prosthodontic treatment for the disabled. Results: 1. 45.6% of dentists felt the necessity of an esthetic prosthesis for the disabled. However, 54.3% of dentists reported the improvement of access to implant,orthodontic and esthetic treatment is needed. 2. Most (79.4%) of the dentists thought it is imperative for the government to support the disabled to maintain adequate oral health by providing at least 50% of charge in their prosthesis. Conclusion: Through this research, 97.1% of dentists answered that the current prosthodontic treatment status for the disabled in Korea is poor. This indicated the necessity of the financial support from the government for the disabled.

• Journal of Korea Association of Health Promotion
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• v.3 no.2
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• pp.199-218
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• 2005

이 연구는 우리나라 20세 이상 성인에서의 대사증후군 유병률을 파악하고 보건의식행태와 대사증후군간의 상관관계를 분석함으로써 대사증후군의 예방 및 치료를 위한 보건교육·건강증진 프로그램의 기초자료로 활용코자 시행되었다. 연구재료로 1998년 국민건강영양조사에 참여한 20세 이상 성인 24,469명 중 건강검진조사를 받았고 건강면접조사, 보건의식행태조사, 식생활조사에 응답한 7,854명의 조사결과를 활용하였으며, 2001년 미국에서 발포된 제 3차 콜레스테롤 관리지침(NCEP-ATP3)에서 제시된 대사증후군 진단기준 및 WH0 아시아/태평양지역 허리둘레를 기준으로 대사증후군 유병률을 분석하였다. 결과는 다음과 같다. 우리나라 20세이상 성인의 대사증후군 유병률은, NCEP-ATP3 기준에서 13.3%(남자 10.1%, 여자 16.0%), 아시아/태평양지역기준에서 19.8%(남자 16.7%, 여자 22.4%)로 아시아/태평양지역 기준에서, 남자보다는 여자에서 더 높았다. 대사증후군 진단항목 중복부비만, 저 HDL-콜레스테롤의 유병를은 여자에서, 고중성지방혈증, 공복시고혈당 유병률은 남자에서 더 높았고, 연령이 증가할수록 대사증후군의 유병률이 증가하였다. 또 대사증후근 진단할목의 보유경향은 ATP3진단기준에서 남자는 복부비만을 제외한 4개항목을 70%이상에서, 특히 고중성지방혈증은 95.0%에서 보유하였다 여자는 저HDL-콜레스테롤과 고중성지방혈증을 70%이상에서 보유하였다. 아시아/태평양 진단기준에서는 남자의 경우 고중성지방혈증을 88.0%에서, 여자의 경우 복부비만 및 저 HDL-콜레스테롤을 80%이상에서 보유하고 있었다. 대사증후군과 보건의식행태 간의 상관관계를 분석한 결과, 교육수준이 낮을수록, 결혼하지 않은 사람에 비해 결혼한 사람에서대사증후군 위험이 증가하였으며, BMI가 증가할수록 대사증후군 위험이 급격히 증가하였고, 고혈압·뇌졸중, 당뇨병 가족력이 있는 남자에서 대사증후군 위험이 증가하였다. 또 스스로 건강하지 않다고 생각하는 사람일수록 현재 흡연자의 PACK- YEAR가높을수록, 자주 술을 마실수록, )회 음주량이 많을수록, 과음빈도가 많을수록 대사증후근 위험이 증가하였으며, 알코올 의존 경향이 있는 경우에서도 유의한 결과를 보였다. 최근 1년간 체중이 감소 혹은 증가된 경우에서 유의한 결과를 보였으며, 체증감소정도가 클수록 대사증후군 위험이 증가하였다. 이상의 결과를 종합해 볼 때, 우리나라 성인의 대사증후군 유병률은 비교적 높으며 대사증후근의 발생에는 보건의식행태, 특히 음주 흡연비만 연령 교육수준 등이 밀접하게 관여한다고 할 수 있다. 그러나 앞으로 대사증후군의 예방을 위한 건강증진 프로그램의 기획 및 치료방침 수립을 위해서는 우리 나라대사증후군의 유병에 영향을 미치는 진단기준항목 및 관련요인의 상호 연관성, 우리나라에 적합한 진단기준 설정 등에 대한 지속적이고 깊이 있는 연구가 이루어져야 할 것이다.

• Journal of the Korean Chemical Society
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• v.60 no.1
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• pp.69-81
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• 2016

The purpose of this study was to find out the validation of instructional strategies using the Advanced Laboratory Equipment (ALE class) by investigating science high school students’ perception on ALE in chemistry classrooms and to consider the need for development of teaching materials on ALE class. 7 sessions of ALE including experiments with innovative equipment were developed and applied to 21 students in D Science High School. At the end of the sessions, questionnaire was given to the students. We also collected qualitative data by interviewing 9 students who participated in the questionnaire. We analyzed the data collected by In-depth interviews and students’ experimental reports. The result showed that ALE class was effective to enhance students’ understanding of learning concepts because the experimental time was shortened in real time data processing. Some students showed creative performance on solving scientific problems by using everyday materials in experimental process and developed perceptions of practical inquiry. Through this process, students’ positive attitudes and interests in science and heuristic inquiry skills were also enhanced. Developing ALE lesson materials will be helpful for students to understand science and technology and the domain of science in broader contexts.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1977.06a
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• pp.5.2-5
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• 1977

Many persons, both children and adults, suffer from impaired hearing. The handicaps that arise from this are economic, educational and above all, social. These persons need help, both medical and educational. In order to plan facilities for the medical treat ment, the rehabilitation, and the special education required by those with impaired hearing, we must know how many persons with hearing problems there are and the severity of their handicaps. The first step in knowing these is to devide hearing impairent into categories of handicap. Historically, since Beasley (1940) proposed progressive stages of deafness in terms of social disability, there was no well organized classification. of hearing handicap except related material from Huzing (1959) and Silverman (1960). In 1965, Goodman advocated a guide hearing threshold levels and degres of relating hearing impairment. During recent one year, on the bases of Goodman classification of hearing impairment and the report from Illinois Comission on children (1968), we have studied about hearing handicaps and speech life for the 180 cases, who visited to our otolaryngology department with hearing impairment. Now, we report the results of study with the referred references.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1070-1079
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• 2012

The impact energy absorbing is a very important characteristic of an aircraft to enhance the survivability of occupants when an aircraft is under the survivable accident such as an emergency landing condition. The impact energy is generally transmitted into the occupant and absorbed through a landing gear, a subfloor (lower structure of fuselage), and a seat. The characteristic of crash energy absorbing of a subfloor depends on the type of an aircraft, a shape of structure, and an applied material. Therefore, the study of crashworthiness characteristics of a subfloor structure is very important work to improve the safety of an aircraft. In this study, a finite element model of a narrow body fuselage section for the 80~90 seats regional aircraft was developed and crash simulation was executed using an explicit finite element analysis. Through survey of the impact energy distribution of each structural part of a fuselage and floor-level acceleration response, the crashworthiness characteristics and performance was evaluated.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.3
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• pp.112-121
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• 2020

In suspension bridges, hanger cables are the main load-supporting members. The tension of the hanger cables of a suspension bridge is a very important parameter for assessing the integrity and safety of the bridge. In general, indirect methods are used to measure the tension of the hanger cables of a suspension bridge in traffic use. A representative indirect method is the vibration method, which extracts modal frequencies from the cables' responses and then measures the cable tension using the cables' geometric conditions and the modal frequencies. In this study, the image processing technique is applied to facilitate the estimation of the dynamic responses of the cables using the image signal, for which a portable digital camcorder was used due to its convenience and cost-efficiency. Ambient vibration tests were conducted on a suspension bridge in traffic use to verify the validity of the back analysis method, which can estimate the tension of remote hanger cables using the modal frequencies as a parameter. In addition, the tension estimated through back analysis method, which was conducted to minimize the difference between the modal frequencies calculated using finite element analysis of the hanger cables and the measured modal frequencies, was compared with that measured using the vibration method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.601-611
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• 2016

The research, development and use of seismic isolation systems have been increasing with the gradual development of structure safety assurance methods for earthquakes. The High Damping Rubber Bearing (HDRB), one type of seismic isolation system, is a Laminated Rubber Bearing using special High Damping Rubber. However, as its damping function is slightly lower than that of the Lead Rubber Bearing, a similar seismic isolation system, its utilization has not been high. However, the HDRB has a superior damping force to the Natural Rubber Bearing, which has similar materials and shapes, and the existing Lead Rubber Bearing has a maleficence problem in that it contains lead. Thus, studies on HDRBs that do not use lead have increased. In this study, a test targeting the HDRB was done to examine its various dependence properties, such as its compressive stress, frequency and repeated loading. To evaluate the HDRB's seismic performance in response to several earthquake waves, the shaking table test was performed and the results analyzed. The test used the downscaled bridge model and the HDRB was divided into seismic and non-seismic isolation. Consequently, when the HDRB was applied, the damping effect was higher in the non-seismic case. However, its responses on weak foundations, such as in Mexico City, represented increased shapes. Thus, its seismic isolator.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.259-265
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• 1997

The main purpose of this research is to provide a basic knowledge of Kimchi and to improve elementary school childrens' Kimchi intake. We researchers have done statistical analyses of 808 questionnaires completed by elementary school children and their mothers on their awareness of and preference for Kimchi. The results were as follows: About 80.2％ of the children regarded Kimchi as one of our nutritious and traditional foods, and 83.8％ of the subjects had an affirmative opinion of Kimchi intake. The most well known Kimchi is as follows: Baechu Kimchi, Kkaktugi, Nabak Kimchl, Chonggak Kimchi, Saaennip Kimchi and Buchu Kimchi. The children preferred the peculiar and refreshing taste of Kimchi. Their preference of Kimchi is in the following order: Baechu Kimchi, Skaktugi, Chonggak Kimchi, Nabak Kimchi and Oi Sobagi. And the children also preferred the stems of the cabbage. The children preferred properly fermented and freshly prepared Kimchi. Their favorite ingredients were red pepper powder, Korean radishes, pickled anchovies, sesame leaves, garlic and scallions. The children wanted Kimchi that is less hot and more sweet. The ingredients children wanted to add to Kimchi are pears, cuttlefish, oranges, apples and cucumbers.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.5
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• pp.263-270
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• 2021

In this study, a reliability-based design optimization of a 130-m class fixed-type offshore platform, to be installed in the North Sea, was carried out, while considering environmental, material, and manufacturing uncertainties to enhance its structural safety and economic aspects. For the reliability analysis, and reliability-based design optimization of the structural integrity, unity check values (defined as the ratio between working and allowable stress, for axial, bending, and shear stresses), of the members of the offshore platform were considered as constraints. Weight of the supporting jacket structure was minimized to reduce the manufacturing cost of the offshore platform. Statistical characteristics of uncertainties were defined based on observed and measured data references. Reliability analysis and reliability-based design optimization of a jacket-type offshore structure were computationally burdensome due to the large number of members; therefore, we suggested a method for variable screening, based on the importance of their output responses, to reduce the dimension of the problem. Furthermore, a deterministic design optimization was carried out prior to the reliability-based design optimization, to improve overall computational efficiency. Finally, the optimal design obtained was compared with the conventional rule-based offshore platform design in terms of safety and cost.