• Title/Summary/Keyword: reliability requirements

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Tungsten oxide interlayer for hole injection in inverted organic light-emitting devices

  • Kim, Yun-Hak;Park, Sun-Mi;Gwon, Sun-Nam;Kim, Jeong-Won
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.380-380
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    • 2010
  • Currently, organic light-emitting diodes (OLEDs) have been proven of their readiness for commercialization in terms of lifetime and efficiency. In accordance with emerging new technologies, enhancement of light efficiency and extension of application fields are required. Particularly inverted structures, in which electron injection occurs at bottom and hole injection on top, show crucial advantages due to their easy integration with Si-based driving circuits for active matrix OLED as well as large open area for brighter illumination. In order to get better performance and process reliability, usually a proper buffer layer for carrier injection is needed. In inverted top emission OLED, the buffer layer should protect underlying organic materials against destructive particles during the electrode deposition, in addition to increasing their efficiency by reducing carrier injection barrier. For hole injection layers, there are several requirements for the buffer layer, such as high transparency, high work function, and reasonable electrical conductivity. As a buffer material, a few kinds of transition metal oxides for inverted OLED applications have been successfully utilized aiming at efficient hole injection properties. Among them, we chose 2 nm of $WO_3$ between NPB [N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine] and Au (or Al) films. The interfacial energy-level alignment and chemical reaction as a function of film coverage have been measured by using in-situ ultraviolet and X-ray photoelectron spectroscopy. It turned out that the $WO_3$ interlayer substantially reduces the hole injection barrier irrespective of the kind of electrode metals. It also avoids direct chemical interaction between NPB and metal atoms. This observation clearly validates the use of $WO_3$ interlayer as hole injection for inverted OLED applications.

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A Study on the Development of Defense Performance Specification and Conversion into it (국방 성능형 규격 작성 및 전환 방안에 관한 연구)

  • Choi, Seok-Cheol;Song, Yu-Ha
    • Journal of the military operations research society of Korea
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    • v.33 no.1
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    • pp.135-155
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    • 2007
  • A performance specification states requirements in terms of the required results, such as performance, environment and interchangeability, but without stating the methods for achieving the required results, such as material and process. therefore the performance specification is applied to attain economic efficiency and high reliability by using the advanced commercial Technology for the weapon systems and The development of performance specification and conversion into performance specification have been activated in the advanced nations. The Ministry of National Defence of Korea has regulated the specification to make performance type in developing specification and prepared performance specification guide. but the result of the development of and conversion into performance specification is very unsatisfactory, To efficiently develop and convert into performance specification, this study gives the way of market research, the creation of the performance specification from development of weapon system and part localization, the process and method for conversion of detail specification into performance specification, the use of hybrid type of performance and detail specification.

Establishment of accreditation criteria for nutrition and dietary education materials (영양.식생활 교육자료의 인증 심사기준 개발 연구)

  • Lee, Kyoung Ae;Kim, Ji-Myung;Park, Yoo Kyoung;Lee, Kyung-Hea;Oh, Sang Woo;Lee, Hee Seung
    • Journal of Nutrition and Health
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    • v.46 no.5
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    • pp.470-481
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    • 2013
  • This study provides standardized scientific criteria for education materials on nutrition and diet that could be used in schools, workplaces, and health and medical facilities. The study was conducted from April 2011 to October 2011. Literature reviews, institutional visits, and telephone interviews were conducted for the first draft of the accreditation criteria. Expert meeting and advisory councils were conducted in order to obtain feedback after development of the first draft of accreditation criteria. In order to verify the validity and reliability of the first draft on certification criteria, a survey was sent out to 143 professionals, including professors, researchers, health and medical experts, teachers, nutrition teachers, dietitians, and clinical nutritionists. After several modifications, the final accreditation criteria were established for 1) printed materials (authority, credibility, objectivity, organization, editing, real-life usability, activities and participation, and public interest), 2) web-sites (authority, credibility, objectivity, design, real-life usability, accessibility, currency, and public interest) and 3) materials with activities (credibility, organization, design, convenience of utilizing, safety, and public interest). Out of several criteria, contents (authority, credibility. and objectivity) and publicity (public interest) areas are mandatory requirements. For the accreditation, books for learning and materials with activities are required to meet more than six evaluation components, and the other materials are required to meet more than five evaluation components, including the required area. Accreditation criteria developed in this study could be used as a standard for development or selection of good education materials for nutrition and dietary life.

Regression Analysis of the Relationships between Complexity Metrics and Faults on the Telecommunication Program (통신 소프트웨어의 프로그램 결함과 복잡도의 관련성 분석을 위한 회귀분석 모델)

  • Lee, Gyeong-Hwan;Jeong, Chang-Sin;Hwang, Seon-Myeong;Jo, Byeong-Gyu;Park, Ji-Hun;Kim, Gang-Tae
    • Journal of KIISE:Software and Applications
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    • v.26 no.11
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    • pp.1282-1287
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    • 1999
  • 통신 프로그램은 고도의 신뢰성과 기능성, 확장성, 그리고 유지 보수성이 필요하다. 프로그램 테스트의 결과와 McCabe의 Complexity를 측정한 데이타를 가지고 회귀모델을 만들고 그 신뢰성을 분석함으로서 프로그램의 결함과 복잡도의 관련성을 평가한다.본 연구에서 사용한 통신 프로그램은 500개 블록이 59가지 기능을 수행하는 교환 기능 중에서 복잡도가 너무 많아서 통계 처리의 bias가 될 블록을 제외하고 394 블록을 선정하여 SAS에 의해서 통계 분석을 하고 회귀 분석 모델을 설계하였다. t 분포에 의하여 방정식의 유의성 수준을 검증하고 프로그램의 결함수에 가장 큰 영향을 주고 있는 복잡도가 McCabe의 복잡도와 설계 복잡도 임을 밝혀냈다. 이 연구 결과에 의해서 설계 정보 및 유지 보수 정보를 얻을 수 있다. Abstract Switching software requires high reliability, functionality, extendability and maintainability. For doing, software quality model based on MaCabe's complexity measure is investigated. It is experimentally shown using regression analysis the program fault density depends on the complexity and size of the function unit. The software should be verified and tested if it satisfies its requirements with automated analysis tools. In this paper we propose the regression model with the test data.The sample program for the regression model consists of more than 500 blocks, where each block compose of 10 files, which has 59 functions of switching activity.Among them we choose 394 blocks and analyzed for 59 functions by testing tools and SAS package. We developed Regression Analysis Model and evaluated significant of the equation based on McCabe's cyclomatic complexity, block design complexity, design complexity, and integration complexity.The results of our experimental study are that number of fault are under the influence of McCabe's complexity number and design complexity.

Cost-based design of residential steel roof systems: A case study

  • Rajan, S.D.;Mobasher, B.;Chen, S.Y.;Young, C.
    • Structural Engineering and Mechanics
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    • v.8 no.2
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    • pp.165-180
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    • 1999
  • The cost effectiveness of using steel roof systems for residential buildings is becoming increasingly apparent with the decrease in manufacturing cost of steel components, reliability and efficiency in construction practices, and the economic and environmental concerns. While steel has been one of the primary materials for structural systems, it is only recently that its use for residential buildings is being explored. A comprehensive system for the design of residential steel roof truss systems is presented. In the first stage of the research the design curves obtained from the AISI-LRFD code for the manufactured cross-sections were verified experimentally. Components of the truss systems were tested in order to determine their member properties when subjected to axial force and bending moments. In addition, the experiments were simulated using finite element analysis to provide an additional source of verification. The second stage of the research involved the development of an integrated design approach that would automatically design a lowest cost roof truss given minimal input. A modified genetic algorithm was used to handle sizing, shape and topology variables in the design problem. The developed methodology was implemented in a software system for the purpose of designing the lowest cost truss that would meet the AISI code provisions and construction requirements given the input parameters. The third stage of the research involved full-scale testing of a typical residential steel roof designed using the developed software system. The full scale testing established the factor of safety while validating the analysis and design procedures. Evaluation of the test results indicates that designs using the present approach provide a structure with enough reserve strength to perform as predicted and are very economical.

Fabrication and Characterization of a GaN Light-emitting Diode (LED) with a Centered Island Cathode

  • Park, Yun Soo;Lee, Hwan Gi;Yang, Chung-Mo;Kim, Dong-Seok;Bae, Jin-Hyuk;Cho, Seongjae;Lee, Jung-Hee;Kang, In Man
    • Journal of the Optical Society of Korea
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    • v.16 no.4
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    • pp.349-353
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    • 2012
  • Uniform spreading of injection current in light-emitting diodes (LEDs) is one of the crucial requirements for better device performances. It is reported that non-uniform current spreading leads to low output power, high current crowding, heating, and reliability degradation of the LED device. This paper reports on the effects of different surface and electrode geometries in the LEDs. To increase the output power of LEDs and reduce the series resistance, a rectangular-type LED (RT-LED) with a centered island cathode has been fabricated and investigated by comparison with a conventional LED (CV-LED). The performances of RT-LEDs were prominently enhanced via uniform current spreading and low current crowding. Performances in terms of increased output power and lower forward voltage of simulated RT-LEDs are much superior to those of CV-LEDs. Based on these results, we investigated the correlation between device geometries and optical characteristics through the fabricated CV and RT-LEDs. The measured output power and forward voltage of the RT-LEDs at 100 mA are 64.7% higher and 8% smaller compared with those of the CV-LEDs.

Factors Influencing Multi-cultural Acceptance of Freshmen in Nursing Colleges (간호대학 신입생의 다문화수용성 영향요인)

  • Jung, Sun-Young
    • Journal of Convergence for Information Technology
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    • v.11 no.10
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    • pp.322-331
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    • 2021
  • This study attempted to identify the multi-cultural acceptance level of freshmen in nursing colleges and to analyze the factors influencing it. For the research method, data were collected from 410 first-year nursing students at K University in W City through a questionnaire from March 1 to 28, 2021, and frequency, reliability analysis, t-test, ANOVA, correlation, and multiple regression were conducted using the open-source statistical package R. As a result of the study, the multi-cultural acceptance level of freshman in nursing colleges averaged 77.36 points, indicating that they have a slightly higher multi-cultural acceptance capacity, and as a result of analyzing the influence of multi-cultural acceptance related factors, Korean recognition requirements(𝛽=0.34, p<.001), perceived threat recognition for migrants (𝛽=0.29, p<.001), Experience in multi-cultural education(𝛽=0.14, p<.001), Recognition of the appropriate age for multi-cultural education (𝛽=0.20, p<.001) was statistically significant. According to results, it is necessary to develop and actively utilize regular curriculum and programs related to multi-culturalism for nursing students.

Comparison of Patient Needs, Patient Satisfaction, and Communication Type of Nurses between Integrated Nursing Care Service Ward and General Ward Patients (간호·간병통합서비스병동과 일반병동 환자의 간호요구도, 간호만족도 및 간호사의 의사소통 유형 비교)

  • Kang, Yeon Jin;Min, Jung A;Park, Chang Soon;Jun, Eun-Young
    • Journal of Home Health Care Nursing
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    • v.28 no.3
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    • pp.317-328
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    • 2021
  • Purpose: The purpose of this study is to provide patient-centered nursing by comparing the patient needs, patient satisfaction, and communication type of nurses for patients admitted to integrated nursing care service ward and general ward. Methods: Data were collected by self-report questionnaires between September 7 and October 9, 2021. Patients were patients recruited from a hospital in D city, 100 each from comprehensive nursing care service ward and general ward. The data were analyzed using descriptive statistics, 𝜒2-test, t-test, ANOVA, and Pearson's correlation. Results: There was no significant difference in patient needs between the patients of integrated nursing care service ward and the general ward (t=-1.12, p=.263). However, patient satisfaction was higher among the patients in integrated nursing care service ward than in the general ward (t=-3.55, p<.001). Pertaining to the communication type of nurses, the informational communication type (t=-4.02, p<.001) and the friendly communication type (t=-3.92, p<.001) were stronger in the integrated nursing care service ward than the general ward. It was, hence, confirmed that the educational requirements were positively correlated with patient satisfaction in the reliability domain and technical-professional domain, and that the nurse informational communication type and friendly communication type had a significantly positive correlation with patient satisfaction. Conclusion: The expansion of the integrated nursing care service ward may be considered in the future, with an informational and friendly communication method as an effective response that can be adapted in practice as a reflection the type of communication among nurses.

An Analysis of Three-Dimensional Head Anthropometric Data to Select Respirators for Korean Users (호흡보호구 선정을 위한 3차원 머리 인체측정학적 데이터의 분석)

  • Park, Jung-Keun;Kim, Se-Dong;Cho, Hyoun-Min
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.31 no.4
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    • pp.521-530
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    • 2021
  • Objectives: This was to examine and explore the elements of Size Korea 6th 3D head anthropometric database and to provide basic information for the selection of respirators in Korea. Methods: This was a pilot study for the first year of work in a two-year-project initiated at KOSHA in 2021. 3D head dimensions data were obtained from the Size Korea Center managing the Size Korea 6th 3D national anthropometry survey databases. The 3D head dimensions data, including 45 dimensions, were used in line with ISO standards (e.g., ISO/TS 16976-2) for examinations, comparisons, statistical analyses, etc. Results: A total of 3,088 subjects were finally determined in this study. The main features were: Male subjects were 52.5%; the highest age group was 15-29 at 36.7%; unhealthy weight group based on BMI was 31.7%; and survey area was the capital region. For the 6th 3D head dimensions data with 45 items, the means and standard deviations for 'Face length' were 115.9±7.5 cm for males and 107.3±6.9 cm for females respectively while those for 'Face width' item were not available since there was no such item in the data. Numerous findings were discussed accordingly. Conclusions: This study showed that there were likely requirements for improvements in the 6th 3D head anthropometric data as follows: Standardization of Korean and English terms; addition of head dimensions items missed in the Size Korea survey; and reliability of generalizability for subjects, suggesting that the study results can be used for further studies or improvement of respirator selection in Korea.

Resistance and Structural Safety of a 3M Carbon Fibier-based Kayak (3미터급 카본 카약의 저항성능 및 구조 안전성 연구)

  • Seo, Kwang-Cheol;Lee, Gyeong-Woo;Park, Joo-Shin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.4
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    • pp.482-488
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    • 2019
  • Leisure and business facilities have been steadily developing in Korea. Among waterborne leisure vessels and equipment, the distribution and sale of kayaks and canoes have significantly increased. Previously, (FRP) materials were primarily employed for constructing kayaks. However, owing to global warming and depletion of natural resources, the demand for non-polluting renewable energy is rapidly increasing, which has increased the demand for carbon fibers. To meet the requirements of changing social consciousness, a carbon fiber-based commercial kayak was designed in this study. Resistance analysis and structural safety were conducted by employing software tool for verifying the reliability of the proposed kayak. The pressure resistance and frictional resistance were examined in a wide range of speed. Obtained results indicate that at speeds greater than 2.6 m/s, the pressure resistance significantly increases and the total resistance also increases. Furthermore, the results corroborate that the proposed kayak structure has a adequate safety with respect to the design loads that are considered during operating conditions.