• 제목/요약/키워드: life-time use

검색결과 1,785건 처리시간 0.027초

초고온 가스로용 Alloy 617의 크리프 수명예측 신뢰성 평가 (Reliability Evaluation on Creep Life Prediction of Alloy 617 for a Very High Temperature Reactor)

  • 김우곤;박재영;김선진;홍성덕;김용완
    • 대한금속재료학회지
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    • 제50권10호
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    • pp.721-728
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    • 2012
  • This paper evaluates the reliability of creep rupture life under service conditions of Alloy 617, which is considered as one of the candidate materials for use in a very high temperature reactor (VHTR) system. A Z-parameter, which represents the deviation of creep rupture data from the master curve, was used for the reliability analysis of the creep rupture data of Alloy 617. A Service-condition Creep Rupture Interference (SCRI) model, which can consider both the scattering of the creep rupture data and the fluctuations of temperature and stress under any service conditions, was also used for evaluating the reliability of creep rupture life. The statistical analysis showed that the scattering of creep rupture data based on Z-parameter was supported by normal distribution. The values of reliability decreased rapidly with increasing amplitudes of temperature and stress fluctuations. The results established that the reliability decreased with an increasing service time.

WIRELESS SENSOR NETWORK BASED BRIDGE MANAGEMENT SYSTEM FOR INFRASTRUCTURE ASSET MANAGEMENT

  • Jung-Yeol Kim;Myung-Jin Chae;Giu Lee;Jae-Woo Park;Moon-Young Cho
    • 국제학술발표논문집
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    • The 3th International Conference on Construction Engineering and Project Management
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    • pp.1324-1327
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    • 2009
  • Social infrastructure is the basis of public welfare and should be recognized and managed as important assets. Bridge is one of the most important infrastructures to be managed systematically because the impact of the failure is critical. It is essential to monitor the performance of bridges in order to manage them as an asset. But current analytical methods such as predictive modeling and structural analysis are very complicated and difficult to use in practice. To apply these methods, structural and material condition data collection should be performed in each element of bridge. But it is difficult to collect these detailed data in large numbers and various kinds of bridges. Therefore, it is necessary to collect data of major measurement items and predict the life of bridges roughly with advanced information technologies. When certain measurement items reach predefined limits in the monitoring bridges, precise performance measurement will be done by detailed site measurement. This paper describes the selection of major measurement items that can represent the tendency of bridge life and introduces automated bridge data collection test-bed using wireless sensor network technology. The following will be major parts of this paper: 1) Examining the features of conventional bridge management system and data collection method 2) Mileage concept as a bridge life indicator and measuring method of the indicator 3) Test-bed of automated and real-time based bridge life indicator monitoring system using wireless sensor network

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중학생의 스트레스와 인터넷 이용동기가 인터넷 중독에 미치는 영향 (The Effect of Stress Among Middle School Students and the Effect of Motive on Their Addiction to the Internet)

  • 박혜영;이은희;박상미
    • 가정과삶의질연구
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    • 제27권6호
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    • pp.65-82
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    • 2009
  • The following research aimed to determine the effect of stress among middle school students on their addiction to the Internet. This research's target was a group of male students who had a high probability of getting addicted to the Internet while playing c/t games. The study distributed 357 questionnaires and used 340 copies, which meant discarding 17 copies that were considered inadequate. The research results are as follows: First, there appeared subordinate factors in the stress suffered by the students. These included stress from their families, from conflicts with their teachers, from the living environment, current schoolwork and future course in college, insecurity over their physical appearance, bullying from other students, and relationships with friends. Among these factors, stress caused by conflicts with teachers and family was the most frequently cited, while stress from their friends was the least cited. The motive in using the Internet was found to be bound with several factors. These include: a form of diversion, a way to communicate with others, a means in coping with loneliness, a source of news and information, a form of passing away time, a kind of habit, and others. Among these motives, passing away time and indulging a habit were cited the most, followed by news and information search, and a form of diversion. Second, as a subordinate factor in Internet addiction, the following were cited: formation of tolerance, health issues, occurrence of problems related to daily life, satisfaction or a pleasant sensation, withdrawal, cover-up on the use of the Internet, and formation of virtual interpersonal relationships, and others. Among these, the formation of tolerance came out the highest, followed by health issues, daily life, and problems related to daily life. Third, in terms of the effects of stress on the motive in using the Internet, the research found that the more the students felt stressed out by conflicts with their teachers and family, the more they tended to use the Internet to communicate with others, to cope with loneliness, to obtain newsI and information, to passawaytime, and to indulge a habit Also, the more they felt stressed out by the living environment, the more they tended to use the Internet to communicate with others, to cope with loneliness, and use news and information. The more they felt stressed out by their schoolwork and future course in college, they tended to use the Internet as a form of diversion and to secure news and information. The more they felt stressed out by their insecurity over their physical appearance and being victimized by bullies, the more they tended to use the Internet to cope with loneliness. Fourth, as for the effect of several variables on student addiction to the Internet, the study found that the more students felt stressed out by their living environment, by schoolwork and future course in college, by their physical appearance, and bullying from other students, the more they used the Internet as a form of diversion, a communication tool, and as a means of passing away time or indulging a habit. The study came up with the finding that the more the students used the computer and the Internet, the probability of their getting addicted to the Internet got higher.

On-Demand Broadcasting for Healthcare Services using Time-Parameterized Replacing Policy

  • Im, Seokjin
    • International journal of advanced smart convergence
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    • 제9권2호
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    • pp.164-172
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    • 2020
  • The interest and importance of the convergence services for healthcare expand more and more as the average life expectancy increases. Convergence of ICT and healthcare technology unfold efficient and quick health services. Recently, healthcare services provide to clients with apps over web. On-demand wireless data broadcast supports any number of clients to access their desired data items dynamically by responding the needs for data items from the clients. In this paper, we propose an on-demand system to broadcast FHIR bundles for efficient healthcare services. We use time-parameterized replacing policy for renewing the bundle items on the wireless broadcast channel. The policy lets the on-demand broadcasting dynamic by controlling the time duration for the bundles to reside over the wireless channel. With simulation studies using an implemented testbed, we evaluate the performances of the proposed system in access time and tuning time. For evaluation, we compare the time-parameterized replacing policy of the proposed system with regular-number replacing policy. The proposed time-parameterized replacing policy shows shorter access time than the regular-number replacing policy because the policy responds more actively and dynamically to the change of the needs of the clients for FHIR bundles.

靑少年의 生活時間 使用變化傾向에 관한 硏究 (An Analysis on Trend of Time Budgets of Korean Younger Generation)

  • 이정덕
    • 가정과삶의질연구
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    • 제9권1호통권17호
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    • pp.203-221
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    • 1991
  • 1) The purpose of this study is to investigate the correlation between general social changes and time budgets of younger generation in Korea. 2) I use the statistics which appeared in the 'Studies of the Time Budgets of Korean people" carried out by the Korean Broadacasting system in 1981 and in 1990. 3) The result of this analysis may be summarized as the following : (1) Even in the cases of biologically necessary acts such as sleeping and eating, the average time used by Korean younger generation is remarkably influenced by general social changes. (2) It is in the cases of optional acts such as reading, listening music and enjoying a move that general social changes influence excessively the time Budgets of children and the youth. (3) It seems that time Budgets of Korean younger generation are losing their balance and rationally year after year during 1981 and 1990. For instance they spend too much time enjoying TV or popular music. 4) As a conclusion, I shall strongly suggest : (1) Parents and school teachers should pay more attention in their guidance of their Children or pupil concerning the importnace of the time Budgest. (2) the programmers of television and radio should consider sincerly the educational influence of their products.

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보험업계(保險業界)의 과제(課題) (Future Medical Screening: A Challenge to the Insurance Industry)

  • 윤병학
    • 보험의학회지
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    • 제12권
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    • pp.50-55
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    • 1993
  • 1) 생명보험(生命保險)에서의 Screening은 사정조건(査定條件)이며 충분(充分)한 기능(機能)을 갖인 기구(器具)이다. 2) Screening 기술(技術)은 의학적(醫學的)으로 충분(充分)히 명시(明示)되여 있으며 장래(將來)에도 일반적(一般的)인 임상적(臨床的)인 Rule에 따라야 한다. 3) Screening Parameter는 연령(年齡)이나 Risk-Group에 의(依)한 질병(疾病)의 Pattern에 따라야 한다. 4) Screening Parameter에서의 예후(豫後)의 추론(推論)은 임상의학적관찰(臨床醫學的觀察)과 Rule를 모두 고처(考處)하는 한(限)에서는 합법적(合法的)이다. 5) 민감(敏感)한 성격(性格)의 Screening 기술(技術)은 일관성(一貫性)있게 취급(取扱)하기 의(依)해서는 대단(大端)히 특별(特別)한 Rule를 필요(必要)로 한다. 6) HIV-항체시험(抗體試驗)과 같은 Screening-Parameter는 그들의 새로운 시험범위내(試驗範圍內)에서는 계속적(繼續的)인 과학적(科學的) Feedback를 필요(必要)로 한다. 7) 유전의학적시험(遺傳醫學的試驗은 생명보험(生命保險) Screening에서는 아직 사용(使用)하고 있지 않지만 생명보험의학(生命保險醫學)에서는 장래(將來)의 역할(役割)과 가능성(可能性)에 대(對)해서 검토(檢討)해야 될 것이다. 8) 보험업계(保險業界)의 Screening은 가능한(可能限) 역선택(逆選擇)을 배제(排除)하고 보험청약자(保險請約者)나 보험자(保險者)의 쌍방(雙方)에서 평균여명(平均餘命)을 짧게하는 어떠한 결함(缺陷)에도 같은 지식(知識)으로 대비(對備)해야 한다. 9) Screening에서의 Informed Consent, Counselling과 Confidentiality는 현재나 더욱 발전된 장래에서도 알맞게 취급하지 않으면 않된다.

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베이커리 카페 고객의 이용 실태 및 성별, 연령에 따른 차이 조사 : 서울 지역을 중심으로 (Differences in Bakery Cafe Use according to Gender & Age : Focused on Customers in Seoul)

  • 최미경;정재찬
    • 동아시아식생활학회지
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    • 제16권2호
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    • pp.156-164
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    • 2006
  • The purposes of this study were to examine bakery cafe use and to identify differences according to gender and age. The questionnaires developed for this study were distributed to 320 males and females aged 20 and over in Seoul. A total of 285 questionnaires were used for analysis(89.1%) and the statistical analyses were completed using SPSS Win (12.0) for descriptive analysis and $x^2-test$. Over 80% of customers used bakery cafes once a month or less, and female customers visited more often than males. The main reasons for using bakery cafe were to chat and then, to buy and eat bakery products. There was a significant difference by age. Average time consumed at a bakery cafe was usually under 1 hour and 30 minutes. Female and younger customers stayed longer than male and older customers, respectively. The majority of customers(85.6%) were accompanied by 2 or less guests and there was no significant difference between the groups. The expenses per person per visit were usually $3,000won{\sim}10,000won$, and the percentage of customers who spent at least 15,000 won was highest in those aged 41 and more. The groups with different gender and age also differed in their choices of products. Customers who are female or under 41 years old used coffees or beverages more often than other group customers. There was no significant difference in understanding on bakery cafe between groups, and 64.9% of respondent answered that they understood bakery cafe as a complex of bakery and cafe. Overall, for early settlement and development of the bakery cafe industry, it seems very important to establish marketing strategy that meets target customers' needs on the basis of understanding their patterns of bakery cafe use.

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대도시 주민의 근린옥외여가시설 선택모형을 기초로 한 시설지 배분에 관한 연구 (A Study on the Facilities Distribution based on the Choice Model of the Outdoor Leisure-Facilities in a Neighbourhood Unit of the Megalopolis Citizens. -In terms of the Comparison of Choice Models and the Limitations of Use Areas between the Megalopolis-)

  • 최기수;김한배;진양교;진상철;허미선
    • 한국조경학회지
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    • 제23권1호
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    • pp.123-139
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    • 1995
  • The megalopolis citizens are reevaluating the expectant value and the perception of leisure aceording to increasing the level of their incomes, The leisure of citizens is increasing in the aspect of quantity and quality of life nowadays In the site planning of leisure, the concrete understanding about people's choice of a leisure site will be the most important thing, not only for the aspect of improvement of the quality of life but also efficiencies of the land use The purposes of chi study are firstly, to find out the factors which are influenced on a choice of Outdoor leisure facilities in neighbourhood unit and to Compare the Characteristics Of Choice models between the three metropolitan areas, secondly, to predict a limitation of use areal according to the change of a needed time based on the metropolitan's standard choice model For the choice model establishment this research used Logit Model which has been used in the field of the traffic, the tourism and the economics. This research made the results which find out the influencing variables with needed times, the accessibility and the percentage of facilities. The lindtations of use areas come out the results which are predicted according to the change of needed times as a most influencing factors. The range of each preferred leisure facility is about 956 meter distant in the neighbourhood park about 644 meter distant in the pocket park about 604 meter distant in the recreation center, about 628 meter distant in the tennis court about 974 meter distant in the private hob by facility and about 528 meter distant in the library from the apartment unit The recreation center and the library are nearer facilities than the other facilities. But these facilities are surveyed to be more or less influenced by an interesting progran, a context of events and the level of useful facilities, etc.

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강원도 영북권역 다빈도 질환 추세분석 (Analysis on the Multiple Frequency Disease Trend of Yeongbuk in Gangwon-do)

  • 이시경
    • 보건의료생명과학 논문지
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    • 제8권2호
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    • pp.135-142
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    • 2020
  • 본 연구는 강원도 영북지역에 주소를 둔 환자의 입원/외래 진료의 이용빈도를 분석하여 영북지역의 의료수요 및 의료이용 현황 파악을 하고자 국민건강보험공단 공공데이터포털(www.data.go.kr) 2003년 부터 2017년까지 건강보험 및 의료급여(입원/외래) 진료비 청구자료를 분석하였다. 다빈도 순위는 '진료건 및 %'에 따라 최빈도의 상병순으로 1-60순위까지의 순위를 선정하였다. 또한, 영북권 유일의 속초의료원 환자의 이용 추이를 병행 분석하였다. 분석결과 강원도 영북지역은 과거 급성기 질환에서 점차 만성인 비감염성 질환의 형태로 상병에 따른 외래 진료 이용과 입원환자의 이용이 증가하고 있다. 특히 조현병과 산과진료의 기능을 확충하고 지역사회의 건강관리에 필요한 구체적인 보건사업을 수행할 필요가 있으며 이를 통해 강원도 영북지역 주민의 삶의 질적 향상을 높여야 한다.

유조선 종통보강재와 횡늑골 연결부의 피로강도 평가용 자동화 시스템 개발 (Development of Evaluation System for Fatigue Strength on the Connection Between Longitudinals and Transverse Web)

  • 홍기섭;김성찬;안재욱;김성기
    • 대한조선학회논문집
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    • 제46권5호
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    • pp.510-519
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    • 2009
  • Ship structure is composed of the welded mixture members which are plate and stiffeners. Ship structure is also influenced by variable loadings such as wave and inertia load. There have been several fatigue damage problems on the connection between longitudinal and transverse web due to wide usage of high tensile steel and adoption of wide web space to improve shipbuilding productivity. It is impossible to estimate the fatigue lives for all connection details through refined fatigue analysis. It is necessary to use the simplified approach for the fatigue life estimation of the connection details. PLUS analysis, which is suggested by the classification society, is one of the simplified approaches and is widely adopted to get fatigue lives for the connection details along whole cargo hold area. However, ship building yards still have difficulties to get fatigue lives due to large amount of calculation and time even if this approach reduce the time and amount of calculation. This paper treats the computing system developed to reduce efforts of estimating the fatigue lives. The influence factors of mean shear stress and local dynamic pressure are easily calculated and fatigue lives for all hot spots can be estimated automatically by the developed computing system. It is possible to reduce computing time and efforts to get the fatigue lives for the connection details between longitudinals and transverse webs along the ship. This system was applied to get fatigue lives on the connection details of a VLCC and verified the availability.