• Title/Summary/Keyword: research methods

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Determination of proper ground motion prediction equation for reasonable evaluation of the seismic reliability in the water supply systems (상수도 시스템 지진 신뢰성의 합리적 평가를 위한 적정 지반운동예측식 결정)

  • Choi, Jeongwook;Kang, Doosun;Jung, Donghwi;Lee, Chanwook;Yoo, Do Guen;Jo, Seong-Bae
    • Journal of Korea Water Resources Association
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    • v.53 no.9
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    • pp.661-670
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    • 2020
  • The water supply system has a wider installation range and various components of it than other infrastructure, making it difficult to secure stability against earthquakes. Therefore, it is necessary to develop methods for evaluating the seismic performance of water supply systems. Ground Motion Prediction Equation (GMPE) is used to evaluate the seismic performance (e.g, failure probability) for water supply facilities such as pump, water tank, and pipes. GMPE is calculated considering the independent variables such as the magnitude of the earthquake and the ground motion such as PGV (Peak Ground Velocity) and PGA (Peak Ground Acceleration). Since the large magnitude earthquake data has not accumulated much to date in Korea, this study tried to select a suitable GMPE for the domestic earthquake simulation by using the earthquake data measured in Korea. To this end, GMPE formula is calculated based on the existing domestic earthquake and presented the results. In the future, it is expected that the evaluation will be more appropriate if the determined GMPE is used when evaluating the seismic performance of domestic waterworks. Appropriate GMPE can be directly used to evaluate hydraulic seismic performance of water supply networks. In other words, it is possible to quantify the damage rate of a pipeline during an earthquake through linkage with the pipe failure probability model, and it is possible to derive more reasonable results when estimating the water outage or low-pressure area due to pipe damages. Finally, the quantifying result of the seismic performance can be used as a design criteria for preparing an optimal restoration plan and proactive seismic design of pipe networks to minimize the damage in the event of an earthquake.

Effects of ionizing and ultraviolet radiation on microbial mutation and DNA damage (전리방사선 및 자외선의 미생물 돌연변이와 DNA 손상에 대한 영향)

  • Nam, Ji-Hyun;Shin, Ji-Hye;Lee, Jung-Yun;Lee, Dong-Hun
    • Korean Journal of Microbiology
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    • v.53 no.1
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    • pp.20-28
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    • 2017
  • Physical sterilization methods using ultraviolet radiation and ionizing radiation such as gamma ray and electron beam are applied in various industry fields due to disinfection effects and economic efficiency but may also cause microbial mutation. In this research, Salmonella enterica and Escherichia coli strains were treated with ionizing and ultraviolet radiation and their survival rate, mutation rate, and DNA damage were studied to evaluate the genetic safety. The survival rate of the strains decreased drastically as the irradiation dose of ultraviolet ray, gamma ray, and electron beam increased, and over 90% of the strain was exterminated at a dosage of $0.40{\sim}25.06mJ/cm^3$, 0.11~0.22 kGy, 0.14~0.53 kGy respectively. In SOS / umu-test, genotoxicity causing DNA damage was identified in all samples. In Ames test, back-mutation rate increased to $3.82{\times}10^{-4}$ and $9.84{\times}10^{-6}$ respectively when exposed to ultraviolet ray and gamma ray. At exposure to ultraviolet ray, gamma ray, and electron beam with dosage of over 99.99% extinction rate of S. enterica TA100, back-mutation rate increased 347 times, 220 times, 0.6 times respectively to the spontaneous back-mutation rate. Rifampicin resistance mutation rate of E. coli CSH100 exposed to ultraviolet ray, gamma ray, and electron beam was $2.46{\times}10^{-6}$, $1.66{\times}10^{-6}$, $4.12{\times}10^{-7}$ respectively. Therefore, gamma radiation is effective in microorganism control from the perspective of disinfection and electron beam has the advantage of sterilizing with little DNA damage and bacterial mutation.

Technology and Home Economics Teachers' Perception of Participation in School Curriculum Organization and High School Credit System (기술·가정과 교사의 학교교육과정 편성 참여와 고교학점제에 대한 인식)

  • Park, Mi Jeong;Lim, Yunjin;Kwon, Yoojin;Lee, Kwangjae
    • Journal of Korean Home Economics Education Association
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    • v.32 no.1
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    • pp.15-34
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    • 2020
  • The purpose of this study was to examine the secondary school technology and home economics teachers' perception of the school curriculum organization and high school credit system. For this purpose, the questionnaire data of 345 secondary technology and home economics teachers nationwide were analyzed through descriptive statistics, t-test, and F-test with SPSS 24. The research results were as follows. First, technology and home economics teachers recognized that current schools lacked the time to organize technology and home economics curriculum (61.1%) and the number of teachers (53%). Most of them have participated (62.0%) and were very willing to participate in the school curriculum organization (4.47, 89.9%). Second, technology and home economics teachers were aware of the high school credit system more than the average (3.34), and more negative (52.8%) than positive (37.7%). As a positive influence, students recognized career choices (3.88) and deepened professional content in their major fields (3.81). On the other hand, the negative impact was the decrease in choice due to non-entry subjects (3.90) and the difficulty in moving teachers to school (3.57). Third, in order to stably respond to the introduction of high school credit system, technology and home economics teachers recognized the importance of coordinating career elective courses (4.51), developing and disseminating teaching and learning materials for elective courses (4.46), separating technology and home economics (4.45), and providing training on evaluation methods and applications (4.44). This study would be useful to provide the basic information and data for the future development of technology and home economics curriculum at the national level based on high school credit system.

Expression of the Peroxisome-proliferator-activated $Receptor-{\gamma}$ in Human Gastric Cancer (위암에서 $PPAR-{\gamma}$ 발현의 임상적 의의)

  • Cho, Dong-Hui;Kang, Sung-Gu;Park, Sang-Su;Yoon, Jin;Kim, Il-Myung;Yoon, Seong-Min;Lee, Yun-Kyung;Lee, Yong-Jik;Yang, Dae-Hyun;Cho, Ik-Hang;Shin, Dong-Gue
    • Journal of Gastric Cancer
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    • v.6 no.4
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    • pp.250-256
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    • 2006
  • Purpose: Recently, interest in peroxisome-proliferator-activated receptors (PPAR) has increased, although clinical studies of the effect of $PPAR-{\gamma}$ expression on gastric cancer have not been reported yet. In this study, we investigated the role of $PPAR-{\gamma}$ expression in gastric cancer patients. Materials and Methods: One hundred twenty-eight (128) samples of both gastric cancer and normal tissues were obtained from 128 patients who had undergone at a curative gastrectomy at Seoul Medical Center from Jan. 2001 to Dec. 2005. $PPAR-{\gamma}$ expression was determined by using immunohistochemical staining, and the results were analyzed. The statistical analysis was based on clinicopathological findings and the differences in survival rates. Results: The mean age of the patients was 6n, and the male : female ratio was 1.9 : 1. $PPAR-{\gamma}$ expression was significantly higher in cancer tissues than in normal tissue (81.3% vs. 57.0%, p<0.001). There was insignificant difference between well and moderately differentiated types and poorly differentiated types in terms of the expression of $PPAR-{\gamma}$ (87.0% vs. 74.6%, P=0.074). In the univariate analysis the survival rate was significantly increased when $PPAR-{\gamma}$ was expressed in normal tissue (P=0.003). In the multivariate analysis, only the UICC TNM staging had significance related to the survival rate. Conclusion: The rate of $PPAR-{\gamma}$ expression was higher in cancer tissue than it was in normal tissue from gastric cancer patients. In the univariate analysis, $PPAR-{\gamma}$ expression in normal tissue had significance with respect to survival, but the multivariate analysis showed no such significance. Thus, we should further evaluate more cases to determine whether or not such a significance exists.

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Evaluation of Psychosocial Impact and Quality of Life in BRCA Mutation Family (BRCA 돌연변이 가계의 심리상태 및 삶의 질 평가)

  • Han, Sang-Ah;Kim, Sai-Rhee;Kang, Eun-Young;Kim, Jeong-Hyun;Ha, Tae-Hyeon;Yang, Eun-Joo;Lim, Jae-Young;Han, Won-Shik;Noh, Dong-Young;Kim, Sung-Won
    • Journal of Genetic Medicine
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    • v.7 no.1
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    • pp.67-77
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    • 2010
  • Purpose: The aims of this study are to evaluate psychological impact and quality of life according to the cancer diagnosis and mutation status in Korean families with BRCA mutations. Materials and Methods: Seventeen affected carriers (AC), 16 unaffected carriers (UC) and 13 healthy non carriers (NC) from 13 BRCA mutation families were included in the study. Outcomes were compared with regard to depression (Beck Depression Inventory), anxiety (State-Trait Anxiety Inventory, STAI), optimism (Reevaluation of the Life Orientation test, LOT-R), knowledge of hereditary ovarian cancer, and quality of life (QoL) (SF-36v2 Health Survey, physical component score [PCS], mental component score [MCS]) among three groups. Result: Level of depression, optimism, and PCS were similar in AC, UC, and NC. Anxiety score was elevated in all three groups. MCS was significantly low in AC than in UC and NC (P=0.009, P=0.017). Knowledge of hereditary breast and ovarian cancer was high in AC than NC (P=0.001). MCS was significantly related to whether patient was affected by cancer (P=0.043) and has occupation (P=0.008) or not in multivariable analysis. Conclusion: From this cross sectional study, psychological adverse effect was not related to the carrier status of BRCA mutation. Elevated anxiety in BRCA family members was observed but, independent to affection and the type of genetic mutation. AC showed low mental QoL. Further effort to understand psychological impact and QoL of genetic testing in BRCA family members is required for follow-up in clinical aspects.

Implantable Flexible Sensor for Telemetrical Real-Time Blood Pressure Monitoring using Polymer/Metal Multilayer Processing Technique (폴리머/ 금속 다층 공정 기술을 이용한 실시간 혈압 모니터링을 위한 유연한 생체 삽입형 센서)

  • Lim Chang-Hyun;Kim Yong-Jun;Yoon Young-Ro;Yoon Hyoung-Ro;Shin Tae-Min
    • Journal of Biomedical Engineering Research
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    • v.25 no.6
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    • pp.599-604
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    • 2004
  • Implantable flexible sensor using polymer/metal multilayer processing technique for telemetrical real-time blood pressure monitoring is presented. The realized sensor is mechanically flexible, which can be less invasively implanted and attached on the outside of blood vessel to monitor the variation of blood pressure. Therefore, unlike conventional detecting methods which install sensor on the inside of vessel, the suggested monitoring method can monitor the relative blood pressure without injuring blood vessel. The major factor of sudden death of adults is a disease of artery like angina pectoris and myocardial infarction. A disease of circulatory system resulted from vessel occlusion by plaque can be preventable and treatable early through continuous blood pressure monitoring. The procedure of suggested new method for monitoring variation of blood pressure is as follows. First, integrated sensor is attached to the outer wall of blood vessel. Second, it detects mechanical contraction and expansion of blood vessel. And then, reader antenna recognizes it using telemetrical method as the relative variation of blood pressure. There are not any active devices in the sensor system; therefore, the transmission of energy and signal depends on the principle of mutual inductance between internal antenna of LC resonator and external antenna of reader. To confirm the feasibility of the sensing mechanism, in vitro experiment using silicone rubber tubing and blood is practiced. First of all, pressure is applied to the silicone tubing which is filled by blood. Then the shift of resonant frequency with the change of applied pressure is measured. The frequency of 2.4 MHz is varied while the applied pressure is changed from 0 to 213.3 kPa. Therefore, the sensitivity of implantable blood pressure is 11.25 kHz/kPa.

An Interactive Cooking Video Query Service System with Linked Data (링크드 데이터를 이용한 인터랙티브 요리 비디오 질의 서비스 시스템)

  • Park, Woo-Ri;Oh, Kyeong-Jin;Hong, Myung-Duk;Jo, Geun-Sik
    • Journal of Intelligence and Information Systems
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    • v.20 no.3
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    • pp.59-76
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    • 2014
  • The revolution of smart media such as smart phone, smart TV and tablets has brought easiness for people to get contents and related information anywhere and anytime. The characteristics of the smart media have changed user behavior for watching the contents from passive attitude into active one. Video is a kind of multimedia resources and widely used to provide information effectively. People not only watch video contents, but also search for related information to specific objects appeared in the contents. However, people have to use extra views or devices to find the information because the existing video contents provide no information through the contents. Therefore, the interaction between user and media is becoming a major concern. The demand for direct interaction and instant information is much increasing. Digital media environment is no longer expected to serve as a one-way information service, which requires user to search manually on the internet finding information they need. To solve the current inconvenience, an interactive service is needed to provide the information exchange function between people and video contents, or between people themselves. Recently, many researchers have recognized the importance of the requirements for interactive services, but only few services provide interactive video within restricted functionality. Only cooking domain is chosen for an interactive cooking video query service in this research. Cooking is receiving lots of people attention continuously. By using smart media devices, user can easily watch a cooking video. One-way information nature of cooking video does not allow to interactively getting more information about the certain contents, although due to the characteristics of videos, cooking videos provide various information such as cooking scenes and explanation for each recipe step. Cooking video indeed attracts academic researches to study and solve several problems related to cooking. However, just few studies focused on interactive services in cooking video and they still not sufficient to provide the interaction with users. In this paper, an interactive cooking video query service system with linked data to provide the interaction functionalities to users. A linked recipe schema is used to handle the linked data. The linked data approach is applied to construct queries in systematic manner when user interacts with cooking videos. We add some classes, data properties, and relations to the linked recipe schema because the current version of the schema is not enough to serve user interaction. A web crawler extracts recipe information from allrecipes.com. All extracted recipe information is transformed into ontology instances by using developed instance generator. To provide a query function, hundreds of questions in cooking video web sites such as BBC food, Foodista, Fine cooking are investigated and analyzed. After the analysis of the investigated questions, we summary the questions into four categories by question generalization. For the question generalization, the questions are clustered in eleven questions. The proposed system provides an environment associating UI (User Interface) and UX (User Experience) that allow user to watch cooking videos while obtaining the necessary additional information using extra information layer. User can use the proposed interactive cooking video system at both PC and mobile environments because responsive web design is applied for the proposed system. In addition, the proposed system enables the interaction between user and video in various smart media devices by employing linked data to provide information matching with the current context. Two methods are used to evaluate the proposed system. First, through a questionnaire-based method, computer system usability is measured by comparing the proposed system with the existing web site. Second, the answer accuracy for user interaction is measured to inspect to-be-offered information. The experimental results show that the proposed system receives a favorable evaluation and provides accurate answers for user interaction.

The Cognition of Design Concepts for Urban Parks - The Cases of Seoul Forest, Yeouido Park, and Seonyudo Park - (도시공원 이용자의 설계개념 인식정도 - 서울숲공원, 여의도공원, 선유도공원을 사례로 -)

  • Joo, Shin-Ha;Kim, Young-Hee
    • Journal of the Korean Institute of Landscape Architecture
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    • v.38 no.5
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    • pp.53-63
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    • 2010
  • The purposes of this study are to classify the characteristics of parks by park use patterns and the understanding of design concepts and to analyze the difference of cognition of design concept between designers and park users. The literature studies and surveys were performed to analyze park use patterns and understanding of design concepts for Seoul Forest Park, Yeouido Park and Seonyudo Park. Several statistical methods have been used such as descriptive analysis and importance-performance analysis. The results of this research are as follows. As the results of an analysis of park use patterns, Seonyudo Park may he qualified as an urban landmark park, while Yeouido Park can he classified as a neighborhood park. Seoul Forest Park bas characteristics of both. Second, the higher frequency of visits generally leads higher preference. Third, the overall cognition of the design concepts of parks shows 3.51 on average, which is comparatively high. The functional concepts are better transmitted to the users compared to abstract concepts. The cognition of the design concepts of each park are evaluated in the higher order of Seonyudo Park, Seoul Forest Park and Yeouido Park. Fourth, the cognition levels of detailed design concepts for each place are lower than the overall design concepts. On the other hand, levels of satisfaction are increased after the design concepts are noticed. It would he necessary make the effort to give information about the design concept of each space. The results of this study are limited in that it covers only three parks in Seoul, and did not consider seasonal variables. Nevertheless, this study may he significant in that it dealt with the cognition of design concepts for urban parks, focusing on the difference between designers and visitors.

User-participatory Design Process for School Forests - Focusing on Daegu Padong Elementary School - (이용자 참여형 학교숲 설계에 관한 연구 - 대구 파동초등학교를 대상으로 -)

  • Jung, Tae-Yeol;Kwon, Ji-Hyun
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.6
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    • pp.50-61
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    • 2017
  • This study devised a user-participatory design process for users to participate directly in the design process and was implemented at Daegu Padong Elementary School. Users of the school forest were divided into four groups: the lower grades, the upper grades, local residents(parents included), and faculty. The methods of this study were image survey, preference survey, card playing, and model playing. Researchers investigated the level of user satisfaction the following year. The specific design process is as follows: First of all, the concept of the school forest was established through audio-visual education for students and image research was conducted through drawing and painting activities entitled 'The School Forest I Want'. Second, in the image survey, a survey of areas and facilities with high frequency use was conducted in the study of the lower grades, the upper grades, local residents, and the faculty. Image cards of spaces and facilities that showed high preference were produced and the cards were placed in four groups on the school lot plan to check the location of place and facilities desired. Based on this, a model and a basic idea were created through consultation with future users. Lastly, the study design was completed. After 1 year from the completion of the school forest, users were again surveyed regarding their satisfaction with use. The importance of this study is as follows: 1) Treating all potential users of a school forest as the subject of design participation, 2) Reasoning out a plan created by the users themselves through consultation and discussion throughout all steps of the design process, 3) Grasping how users utilize a school forest and the type of spaces most preferred via preference survey after completion of the school forest and showing the importance of user participation by showing that spaces preferred by users were similar to those in which experts were also highly interested.

Effects of the color components of light-cured composite resin before and after polymerization on degree of conversion and flexural strength (광중합형 복합레진의 중합 전, 후의 색 성분이 중합률과 굴곡강도에 미치는 영향)

  • Yoo, Ji-A;Cho, Byeong-Hoon
    • Restorative Dentistry and Endodontics
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    • v.36 no.4
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    • pp.324-335
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    • 2011
  • Objectives: This study investigated the effects of the color components of light-cured composite resin before and after polymerization on degree of conversion (DC) and biaxial flexural strength (FS). Materials and Methods: Four enamel shades (A1, A2, A3, A4) and two dentin shades (A2O, A3O) of Premisa (Kerr Co.) and Denfil (Vericom Co.) were evaluated on their CIE $L^*,\;a^*,\;b^*$ color components using the spectrophotometer before curing, after curing and at 7 day. The DC of same specimens were measured with Near-infrared spectrometer (Nexus, Thermo Nicolet Co.) at 2 hr after cure and at 7 day. Finally, the FS was obtained after all the other measurements were completed at 7 day. The correlations between each color component and DC and FS were evaluated. Results: The light-curing of composite resin resulted in color changes of Premisa in red-blue direction and Denfil in green-blue direction. The DC and FS were affected by product, time and shade (3-way ANOVA, p < 0.05) and product and shade (2-way ANOVA, p < 0.05), respectively. Premisa only showed a significant correlation between the DC and CIE $a^*$ component - before and after polymerization (Pearson product moment correlation, p < 0.05). The FS of Premisa showed significant negative correlations with CIE $a^*$ and CIE $b^*$ components. Conclusions: The DC and FS of the light-curing composite resin were affected by the color components of the material before and after polymerization.