• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.2
• /
• pp.149-156
• /
• 2017

Nuclear fuel requires high reliability and safety and therefore contains debris filtering devices to prevent failure-inducing debris from entering it. The debris filtering performance of nuclear fuel is one of the most important factors for fuel integrity. Therefore, the performance must be evaluated and the measurement must be reasonable. In this study, a calculation method of the comprehensive filtering efficiency using the weighted mean was proposed to establish a standard filtering efficiency index. To confirm the suitability of the proposed method, representative debris specimens were selected and the filtering efficiency with the weighted mean was compared with the efficiency of the arithmetic mean. The weighting factor of the weighted mean was introduced to produce a fair evaluation. In addition, the analysis of the debris filtering mechanism was performed according to the size of debris specimens, and the main dimensions of the filtering feature for commercial nuclear fuel.

• Journal of Korean Society of Transportation
• /
• v.33 no.1
• /
• pp.29-39
• /
• 2015

Currently, level of service(LOS) analysis methods for pedestrian sidewalks are provided in Korean Highway Capacity Manual(KHCM, 2013). However, conventional methods provided in the KHCM produce most of pedestrian sidewalks' LOS as level A, indicating that existing analysis methods are unable to reflect realistic pedestrian sidewalks' LOS. The objectives of this research are to identify the suitability of current LOS criteria and to propose improved LOS evaluation criteria and methods with pedestrian volume data carried out for 10,000 sites in 2009. This research proposes new criteria by using the qualitative definition of LOS proposed by Fruin and Hall, new standard Korean human scale and new criteria of pedestrian occupancy space. Application results of new criteria show that more realistic results can be achieved than the existing methods. It is expected that applying the newly developed criteria and methods can make planning, design and construction of pedestrian sidewalks more realistic and various.

• Fashion & Textile Research Journal
• /
• v.11 no.2
• /
• pp.278-285
• /
• 2009

As children's apparel industry expands, there are many researches on purchasing and wearing children's clothing and optimal sizes, but researches on purchasing and wearing children's clothing and the appropriateness of sizes comparing average body shape and obese children are still inadequate. Therefore, in this research Late Elementary Schoolgirls ranging in age from 12 to 13 are categorized into the average or the obese body type, and by comparing and analyzing purchasing and wearing children's clothing and the appropriateness of its sizes between these groups, the problems in the size system of children's apparel are realized and the basic information about designing children's clothing for average body shape and non-average body shape(out-size)children are presented. The survey questions were composed of topics about general personal information, the purchasing practice and wearing practice, the appropriateness of its size when wearing children's clothing and the practice of mending apparel according to the satisfaction level of children's clothing sizes. Because subjects are often too big to wear children's clothing, and in the case of obese children the deviation of a body type is amplified, therefore in buying and wearing children's clothing, they demonstrate different forms of purchasing and wearing characteristics than adults. Considering the practice of increasing obesity in children due to westernized eating habits and decreased physical activities, along with developing programs for improving obesity, the development of an optimal size system in response to various body types will become an important challenge.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.19 no.3
• /
• pp.122-129
• /
• 2015

In this study, a prediction model for the effective compressive strength of corner columns with intervening normal strength concrete slabs was developed. A structural analogy between high-strength concrete column-normal strength concrete slab joint and brick masonry was used to develop the prediction model. In addition, the aspect ratio of slab thickness to column dimension was considered in the models. The reliability of the new prediction model was evaluated by comparison with experimental results and its superiority was demonstrated by comparison with previous models proposed by design codes and other researchers. As a result, with average test-to-predicted ratios of 1.09, a standard deviation of 0.15, the newly developed equation provided superior predictions in terms of accuracy and consistency over all of the existing effective strength prediction approaches including KCI structural concrete design code (2012).

• Journal of Information Management
• /
• v.42 no.3
• /
• pp.117-145
• /
• 2011

This research tries to develop standards of library goods and managerial guidance. It is developed to make buying and managing library goods efficient in promoting environmental and digital-friendly library, and to set a standard guidance of library goods. The research divides 117 library goods into 6 categories, and develops a table of recommended standard and managerial guidance of library goods. The table has 11 indicators of information, which includes the name of each library goods, classification code, identification number of 'Narajangteo', definitions of the goods, purpose and usage, type and size, structure, place to install, goods management, and note. The research hopes to be reflected in library related laws, standards, and manuals, and finally to standardize library goods in the national level.

• The Journal of the Acoustical Society of Korea
• /
• v.35 no.6
• /
• pp.466-472
• /
• 2016

In this work, a medical linear array ultrasonic transducer working in the range of 20 MHz has been developed for high-resolution ultrasonic imaging. After devising the structure of the transducer suitable for the transmission of high-frequency waves, we optimized the dimension of constituent components. Then, the process to fabricate the transducer was developed to realize the designed structure, and a prototype of the transducer was fabricated and characterized. The center frequency of the fabricated transducer was measured to be 19 MHz, and the fractional bandwidth to be 84.5 %, and the standard deviation of the sensitivity over the entire channels to be 0.74 dB. These measurement results showed good agreement with design data, which confirmed the validity of the high frequency ultrasonic transducer structure developed in this work. It was confirmed that the developed transducer with new structure had wider frequency bandwidth and uniform sensitivity than a conventional 20 MHz transducer.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.5
• /
• pp.433-442
• /
• 2014

The most design criteria and specifications in Korea utilized to ensure appropriate quality are based on process and prescriptive criteria determining materials, measure and methods. It has many problems including a loss of competitiveness resulting from inhibited creativity of the contractors. The performance-based specifications focused on final product are being proposed, but have difficulty in adapting to the architectural field. In this study the hybrid specification prototype for curtain wall construction was suggested. The specification framework was presented through analysis of linkage between the performance and prescriptive specification cases. Based on the survey with practitioners, the performance inspection process and the sample specification were developed by identifying the essential performance test timings. The applicability of the specification prototype was evaluated by interviews with experts. It was found that the prototype was active and a progressive supporting tool which could support to secure phased performance during construction as well as final performance.

• Journal of the korean Society of Automotive Engineers
• /
• v.8 no.1
• /
• pp.22-28
• /
• 1986

기관의 성능에 영향을 주는 인자로서는 외적인자(outside factor), 작동인자(operating factor) 및 설계인자(design factor)의 3가지로 나눌 수 있다. 작동인자로서는 기관회전수, 공기연료비, 점화 시기 또는 분사시기 등이면 설계인자로서는 행정체적, 압축비, 흡배기계통의 구조 및 치수, 냉각 방식 등으로 기관에 따라 고유한 값을 가지는 인자이다. 그러나 외적인자인 대기조건 즉 대기 압력, 대기온도 및 대기습도는 계절, 지역 및 기상조건에 따라 달라지므로 이것에 따라 기관이 흡입하는 공기의 압력, 온도 및 습도는 변화하게 된다. 그러므로 대기조건의 변화에 따라서는 기관작동인자인 공기연료비에도 영향을 미치게 할 것이고 또한 연소상태의 변화로 유효압축비 에도 영향을 미치게 할 것이므로 대기상태의 변화는 곧 바로 기관 출력의 변화를 초래하게 될 것이다. 그러므로 같은 운전조건에서의 기관출력도 대기상태의 변화에 따라 변화하게 되므로 임의의 대기 상태에서 측정한 기관출력을 표준대기상태의 기관출력으로 환산해서 평가할 필요가 생긴다. 이것을 일반으로 출력수정(output correction)이라 하고 있으며 각 나라마다 공업규격 또는 기타규격으로 출력정식을 제정하고 있다. 예를 들면 K.S.B 9102, SAE J816B, B.S. 765, DIN 70020, JIS B 8013등이다. 이들 출력수정식들은 많은 문제점을 가지고 있으므로 종래의 출 력수정식으로 출력수정을 하여도 정확하게 맞지 않은 경우가 많다. 출력수정에 관한 문제는 수 10년전부터 많은 연구자에 의하여 연구되고 거론되어 왔으나 과거의 연구자들이 제안하고 거론 되어 왔으나 과거의 연구자들이 제안하고 있는 출력수정식, 또는 규격으로 정하고 있는 출력수 정방법은 어느 것이나 실용상 만족스러운 것이 아직 없다. 그러므로 본 자료는 스파아크 점화 기관의 흡기습도에 관한 출력수정의 문제를 실험적으로 수행한 실험적 출력수정방법에 의한 것과 종래의 출력수정방법에 의한 것과를 비교 검토하였다.

• Journal of Convergence for Information Technology
• /
• v.9 no.2
• /
• pp.85-93
• /
• 2019

There is currently no recognized standard for the size of lifts. Each elevator manufacturer sets the maximum allowable floor area that meets the capacity calculation standard of the elevator using the maximum used car floor area, which is defined by EN-CODE and the domestic inspection standard, and determines the elevator size based on their own standards. In this paper, we propose a method to more easily determine the elevator size. To do this, we implemented a program that calculates the size of the elevator by inputting the dimensions of the hoistway. This program will be useful method for quick decision making and elevator installation considering the elevator factors according to the already determined hoistway size of the building and calculating the EN-CODE currently used and the size of the elevator according to domestic inspection standards.

• Journal of the Korea Institute of Building Construction
• /
• v.19 no.3
• /
• pp.229-237
• /
• 2019

This study examines the estimation of strength through a ultra-high strength concrete mock-up specimen using the rock compressive strength test hammer. According to the test result, the commonly used strength estimation formulae showed differences among them when the data of this test were applied. In additional, it show that these formulae underestimated the actual measurements further when the compressive strength was 30MPa or greater and deviated the distribution range of actual measurements in all strength ranges. The rock test hammer showed a higher correlation than type N Schmidt hammer regardless of the direction of hit for each type of W/B and the inclusion of coarse aggregate, and mortar showed a little higher correlation than concrete. As a result, it can be suggested that the coefficient of variation and the standard deviation of the mortar(2.26%/1.36) are lower than those of the concrete(4.06%/2.5), and the smaller the size of the coarse aggregate, the smaller the coefficient of variation and the more accurate the value.