• Journal of Advanced Marine Engineering and Technology
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• 제38권10호
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• pp.1225-1231
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• 2014

This paper presents the performance characteristic of a Francis hydro turbine with an inline casing. This turbine is designed for city water supply system. Due to large changes in ground elevation with high points and low points, some systems may experience larger-than-normal required pressures in areas with low ground elevations. One way to dissipate these excess pressures is by the use of an inline-turbine instead of an inline-pressure reducing valve. For best applicability and minimal space consumption, the turbine is designed with an inline casing instead of the common spiral casing. As a characteristic of inline casing, the flow accesses to the runner in the radial direction, showing a low efficiency. The installation of vanes improves the internal flow and gives the positive encouragement to the output power. For the power transmission to the outside of the turbine casing from the runner axis, a belt passage is designed in the inline casing, as its influence, the region after the belt passage shows a relatively low output power. The clearance gap in the runner side space is considered, in which a small volume of flow is contracted into the clearance gap, forming the leakage flow. The leakage flow leads to a decrease in the efficiency.

• Journal of Advanced Marine Engineering and Technology
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• 제40권5호
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• pp.397-402
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• 2016

This study presents the performance characteristics of a small Francis turbine with an inline casing and is a continuation of a previous study. A new runner design has been implemented using the previous facility. The specific speed of the new runner has been modified from $N_s$ 80 to $N_s$ $100m-kW-min^{-1}$. This turbine can be installed in a city water supply system. To dissipate excess pressures in the water line system an inline-turbine can be used instead of an inline-pressure reducing valve. Thus, some of the energy can be recovered by utilizing the pressure difference. For best applicability and minimal space consumption, the turbine is designed with an inline casing instead of a common spiral casing. As a characteristic of inline casing, the flow accesses to the runner are in the radial direction, showing low efficiency. The installation of vanes improves the internal flow and positively affects the output power. In contrast to the previous study, the new runner reduces the effect of the stay vanes by maintaining a higher efficiency.

• Child Health Nursing Research
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• 제8권4호
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• pp.381-390
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• 2002

This study examines the factors that are associated with accidents from riding on inline skates and/or kick boards among students in the elementary schools. Data were collected from 902 students in 3 elementary schools in Seoul. Data were analyzed based on descriptive statistics and chi-square test. The results were as follows: 1. Thirty-eight percent of the students investigated were found to have kick boards while sixty-one percent of the students had inline skates. 2. The age of mothers who answered the questionnaires showed a statistically significant association with injuries of their children on inline skates and/or kick boards. Children whose mothers are younger had a lower percentage of injuries on inline skates and/or kick boards. 3. Children with a lower score on K-CBCL had a higher chance of having an accident from riding on inline skates and/or kick boards. That is, children with lack of attention were more likely to be involved in an accident. First-born children were less likely to have an accident. 4. While mothers' attitudes toward the safety of inline skates and kick boards appeared not to be associated with accidents of their children, their preventive actions for the safety related to riding on inline skates and kick boards reduced the chance to be involved in an accident of their children. In conclusion, this study shows that mothers with children going to the elementary schools should be more action-oriented to prevent their children's accidents from riding on inline skates and/or kick boards than merely recognizing the safety of inline skates and/or kick boards on their own. Implication of these findings and major findings of this study were discussed.

• 한국유체기계학회 논문집
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• 제15권3호
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• pp.32-38
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• 2012

This paper is aimed to propose the design database(DB) of the inline micro-turbine for 5kW class. CFD analysis is performed to investigate the effect of a turbine on each parameter. This study showed that RadhaKrishna's data is different from the 5kW class in the low-head and the micro-turbine. Therefore, new DB for the design of inline micro-turbine for 5kW class could be needed. This study configured new design DB for the design of inline micro-turbine for 5kW class. The DB of this study showed that the optimal hub ratio(Dp/DR), the optimal body ratio(Db/DR) and the optimal range of body length ratio(Lh/DR) is 50%, 1.1 and 2.3 to 2.9, respectively.

• 한국안전학회지
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• 제26권2호
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• pp.1-5
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• 2011

In order to evaluate fatigue endurance for an ultra-light weight inline skate frame, FEM analysis was performed. Tensile properties and a S-N curve were determined through tensile and fatigue tests on a modified Al-7075+$S_c$ alloy. The yield and ultimate tensile strengths were 553.3 MPa and 705.5 MPa, respectively. The fatigue endurance limit of this alloy was 201.2 MPa. For evaluating the fatigue endurance of the inline skate frame, the S-N data were compared with the stress analysis results through FEM analysis of the frame. The maximum Von-Mises stress of the frame was determined 106 MPa through FEM analysis of the frame, assuming that the rider weight is 75 Kg. Conclusively, on the basis of fatigue limit, the inline skate frame has a safety factor of approximately 2.0.

• Journal of Pharmaceutical Investigation
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• 제40권4호
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• pp.225-230
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• 2010

The particulate contamination of intravenously administered fluid has been of major concern. One of the most common complications associated with long term i.v. therapy is post-infusion phlebitis (PIP). We undertook a systematic review and meta-analysis of the effect of inline filters on PIP. An electronic search of Medline, KoreaMed, and KRIST was conducted to identify randomized controlled trials evaluating the effect of inline filters. Meta-analysis was undertaken using STATA 10. A total of 62 literatures were retrieved, of which 7 were included in meta-analysis. Inline filtration for intravenous infusion significantly reduced by 39% of the incidence of phlebitis, with a relative risk of 0.61 (95% CI 0.41-0.90, p=0.012). Therefore, inline filtration is a highly effective means of decreasing the incidence of infusion phlebitis and should be considered as a part of intravenous therapy.

• 한국유체기계학회 논문집
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• 제18권2호
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• pp.5-13
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• 2015

The aim of this study is to investigate the feasibility of a new type of casing for the inline Francis hydro turbine. Comparing with the traditional turbine with spiral casing, this turbine is unique for its flow passage shape at the first stage of flow to the turbine, very similar to a pipe, called inline casing. Before the commercialization of this new type of casing, a global investigation of the inline casing must be conducted. Preserving the structural characteristics of simple, compact-size and convenient for manufacture, different shapes of the belt passage, vertical corner and stay vanes are applied to investigate the influence of flow passage shape on the turbine performance. Stable and relatively high efficiency is achieved regardless of flow passage shape difference proving the feasibility of the inline casing used in a hydro turbine.

• 한국정밀공학회지
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• 제16권3호통권96호
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• pp.30-37
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• 1999

This paper represents the development of the brake system for the inline skate using bellows. The inline skate that is used at present has defects due to frequent impulse, which weakens the breaking force by damaging the parts. Therefore to solve these problems a break system for the inline skates using hydraulics is suggested. To solve the oil leakage problems, bellows is used. Also to prevent the breaks from not touching the ground when skating the bellows is placed at the heel, high as possible. To obtain fast response speed, the ratio of inner diameter of the bellows is changed so that with only a small displacement from the bellows the rubber pad attached to the bellows will touch the ground fast. The performance of the break system using bellows depends on the optimal design of the bellows. Therefore the parameters that changes the form of the bellows are tested and also the interaction between the forces are investigated. The performance of new model brake system with bellows and old model system with only a rubber pad without bellows was estimated through observation of braking posture.

• 한국전자파학회논문지
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• 제30권1호
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• pp.54-59
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• 2019

본 논문에서는 밀리미터파 대역에서 동작하는 inline 구조를 이용한 도파관-마이크로스트립 전이구조를 설계 및 제작하였다. 도파관-마이크로스트립 전이구조는 프로브, 인덕턴스 선로, ${\lambda}/4$ 임피던스 변환기, 그리고 50 ohm 마이크로스트립 선로로 구성되어 있으며, 각 구성 요소들의 특성 임피던스 및 길이를 시뮬레이션을 통하여 최적화하였다. 제작된 전이구조의 측정 결과, 밀리미터파 내 중심 주파수 94 GHz 구간에서 평균 2.1 dB 삽입손실 특성 및 13 dB 이하의 입출력 반사 손실 특성을 나타내었다.

• 한국CDE학회논문집
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• 제10권1호
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• pp.17-26
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• 2005

In-line skate generally consists of four major parts: boot, frame, bearing and wheel, and the most important part among those for necessary functionality is the frame. It is the most expensive, and it also makes a decisive role in practical race skating. The functional behavior of a frame is greatly affected by external dynamic forces as well as the static weight of a skater. We are proposing a new inline speed-skating frame design that has been improved in structural strength and weight for providing optimum speed in $20\sim40km$ marathon skating.