• Design & Manufacturing
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• v.10 no.2
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• pp.50-54
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• 2016

In the semiconductor industry the final products were checked for several environments before sell the products. The burning test of memory and chip was implemented in reliability for all of parts. The memory and chip were developed to high density memory and high performance chip, so circuit design was also high integrated and the test bed was needed to be thin and fine pitch socket. LGA(Land Grid Array) IC socket with thin wall thickness was designed to satisfy this requirement. The LGA IC socket plastic part was manufacture by injection molding process, it was needed accuracy, stiffness and suit resin with high flowability. In this study, injection molding process analysis was executed for 2 and 4 cavities moldings with runner, gate and sprue. The warpage analysis was also implemented for further gate removal process. Through the analyses the total deformations of the moldings were predicted within maximum 0.05mm deformation. Finally in consideration of these results, 2 and 4 cavities molds were designed and made and tested in injection molding process.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.114-128
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• 2019

Recently, the interest in the safety of autonomous vehicles has globally been increasing. Also, there is controversy over the reliability and safety about autonomous vehicle. In Korea, the K-City which is a test-bed for testing autonomous vehicles has been constructing. There is a need for test scenarios for autonomous vehicle test in terms of safety. The purpose of this study is to develop the evaluation scenario for autonomous vehicle at community roads in K-City by using crash data collected by the Korea National Police Agency and a text-mining technique. As a result, 24 scenarios were developed in order to test autonomous vehicle in community roads. Finally, the logical and concrete scenario forms were derived based on the Pegasus 5-layer format.

• Smart Structures and Systems
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• v.16 no.5
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• pp.873-889
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• 2015

In civil engineering, probabilistic seismic risk assessment is used to predict the economic damage to a lifeline system of possible future earthquakes. The results are used to plan mitigation measures and to strengthen the structures where necessary. Instead, after an earthquake public authorities need mathematical models that compute: the damage caused by the earthquake to the individual vulnerable components and links, and the global behavior of the lifeline system. In this study, a framework that was developed and used for prediction purpose is modified to assess the consequences of an earthquake in quasi real-time after such earthquake happened. This is possible because nowadays entire seismic regions are instrumented with tight networks of strong motion stations, which provide and broadcast accurate intensity measure maps of the event to the public within minutes. The framework uses the broadcasted map and calculates the damage to the lifeline system and its component in quasi real-time. The results give the authorities the most likely status of the system. This helps emergency personnel to deal with the damage and to prioritize visual inspections and repairs. A highway transportation network is used as a test bed but any lifeline system can be analyzed.

• Journal of KIISE
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• v.44 no.12
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• pp.1307-1312
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• 2017

Due to their convergence with state-of-the-art ICT technologies, the complexity and reliability demands of industrial automation systems have been rapidly increasing. In recent years, to cope with these demands, several research works have been carried out to adopt formal methods to the application development cycle at the early design stage. In this paper, we propose an automated code generation framework for industrial automation applications, based on a timed automata model. As a case study, we developed a formal model for a traffic light control system and verified the timing properties described in the specification. We finally demonstrated that the operation of a test-bed based on the auto-generated native code was identical to that of the model specification.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.19-20
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• 2006

The emission of particulate matter from marine diesel engines is already restricted by regional regulations in some countries, and IMO has been preparing the regulation for particulate matter from 53rd MEPC. But confusingly, the gravimetric PM measurement methods and procedures are not established clearly yet. On the other hand, smoke measurement method is set clearly, and it can also indicate PM, though it is not direct gravimetric method. As the preparing step for regulations about PM, we measured the smote density of exhaust emission from the marine four-stroke diesel engines operated in constant speed and various load steps on the test-bed, using the filter-type smoke measuring instrument. As a result, we understood the omission characteristics of smoke from the engines. Additionally, to obtain the objective reliability of our measurement data, we carried out experimental studies about various measuring parameters that could affect the smoke density.

• Water for future
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• v.22 no.3
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• pp.315-322
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• 1989

The effects of open boundary conditions including the radiation condition are compared by utilizing the $L^{2_}$-norm and RMS error in the numerical modeling of ocean problem. In numerical tests of $M_2$ tide, grid size and bed roughness are considered and analyzed. For the $M_2$ tide test in a simplified bay where the analytical solutions are available, it is found that improved radiating boundary condition(IMPSOM) may increase the reliability of computed results by 40% of $L^{2_}$-norm and 96% of RMS error than the open boundary condition without radiation effect. In case of using the half-size grids, better results are obtained. It is also found that the IMPSOM is applicable with satisfaction when the bottom friction is included.

• Journal of Internet Computing and Services
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• v.20 no.1
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• pp.11-16
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• 2019

Wireless sensor network is important for precision farming to monitor the growth environment of crops in open field, but radio signals are susceptible to different types of interference such as weather and physical objects. This paper designs and implements an environmental monitoring and weather forecast acquisition systems for smart field irrigation based on LoRa(Long Range) and then applies it to a test bed. And we evaluate the network reliability in terms of packet transmission success rate by comparing its condition on two criteria; the existence of obstacle or rain. The results show that much rain falls can affect on packet loss in LoRa field networks with obstacles.

• Korea Journal of Hospital Management
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• v.7 no.4
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• pp.123-151
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• 2002

The objective of this study is to analyze the causal relationship of hospital inpatient's perceived quality, overall satisfaction, service value, and future intention to revisit. To carry out this objective, first we analyzed the dimensions of inpatient care service quality using SERVQUAL scale. The SERVQUAL scale is based on the gap theory, that is, the difference of patients' expectations and the actually received medical care service in hospital. On the basis of this theory, we measured the inpatient's perceived service quality and overall patient satisfaction. Data was gathered from a self-administered questionnaire at a 980 bed university hospital in Inchon City. These questionnaire measuring the service quality were distributed to 250 inpatients. The response rate was 66.4%. A total of 166 questionnaires was finally analyzed. To categorize medical service quality, the factor analysis was performed on 42 items. The reliability and validity of these items was evaluated. Finally to test 6 hypotheses, we analyzed the causal relationship of service quality, overall satisfaction, service value, and intention to revisit through the structural equation modeling(SEM). The major results of this study are as follows. First, the dimension of inpatient service quality was categorized into 7 dimensions, that is, personal caring, communication, access, physical environment, facilities and equipment, cleanliness, appropriateness and health status. Second, the reliability and validity of inpatient service quality items was satisfied. Third, as a result of structural equation modeling, the effect of inpatient's perceived service quality on overall satisfaction, service value, and intention to revisit was statistically significant. And total effect on intention to revisit as the core endogenous variable was perceived service quality(1.100), patient satisfaction(0.006), and service value(0.605).

• Journal of Korean Academy of Nursing Administration
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• v.3 no.2
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• pp.81-94
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• 1997

Cardiac catheterization has become a routine diagnostic procedure indicated for evaluation of a wide variety of cardiac conditions. Patients are admitted to the coronary care unit after cardiac catheterization. These conscious patients used to report discomfort in the CCU, but no studies have been done to reduce discomfort induced by bed rest, sand bag on the femoral puncture site and restricted mobility for about 20 hours postprocedure. The main objective of thesis is to provide basic data to nursing on interventions which decrease discomfort perceived by patients in the CCU following cardiac catheterization. The subjects were 79 patients following cardiac catheterization who were admitted to the CCU of a general hospital in Inchon. These patients were divided into a massage-applied group, an exercise-applied group and an contrast group. Questionare was prepared by Lee(1995), and tested for content reliability by item analysis : Cron bach's ${\alpha}$ for the instrument measuring discomfort was. 63. The data were collected from January 25 to May 15, 1996. Analysis of data was done by paired t-test, ANOVA ,SNK test, Chi-square test. The results of the study are summarized as follows : 1. There were no significant differences among a massage-applied group, an exercise-applied group and an contrast group according to general information except religion and admission period. 2. There were found no significant differences among the three groups in the results of pretest (The score of the first : 55.5, the second : 54.3 and the last : 51.6), 3. In the degree of discomfort according to general characteristics were found some significant differences for marital status. But there were no significant differences for sex, age, occupation, number of family, religion, educational status and admission period. 4. There was effect on reduced discomfort with massage or exercise following cardiac catheterization.

• Women's Health Nursing
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• v.1 no.1
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• pp.119-137
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• 1995

Maternity nurses' roles are to find out women's various responses related to the health problems during pregnancy, to intervene adequate nursing and supports, and to help them adapt satisfactorily to new situation, such as hospitalization. The purposes of this study are : firstly, to inquire about women's emotional status, feeling of discomfort, and the nursing need during hospitalization because of discomfort, and the nursing needs during hospitalization because of the possibility of abortion by threatened and habitual abortion : secondly, to provide fundamental data for developing adequate nursing intervention and improving hospital management. The subjects of this study were 62 women who were hospitalized, visited out-patient clinic for follow-up, and stayed at home after discharge since August, 1993 from one hospital located in Seoul, from March 23 to April 13, 1994. The questionnaire was consisted of 21 items of emotion(Reliability Cronbach's alpa, .77), 19 items of feeling of discomfort(.79), and 21 items of nursing needs (.89), and nurses' performance according to nursing needs,(.90). These were measured by using Likert Scale and analyzed by using SPSS / $PC^+$ with the descriptive statistics, $X^2$-test, and ANOVA. Research findings are as follows : 1) The subjects' average age, hospitalized days, and gestational age are 32.2, 15.7, 12.9 by respectively. 2) 88.7% of the subjects are getting antepatal care, 66.1% are experiencing 1.75 times of spontaneous abortion, and 82.3% are nuclear family. 3) The Emotions were mainly comprized negative and subjective state of minds such as uneasiness, anxiety, and discomfort. The domains of emotions were related to 'fetus', 'herself', 'hospitalization', and 'husband's 'families', in rank. The highest scored item was "I, above anyone else, am mostly stressed from abortion." 4) The feelings of discomforts were firstly related to 'personal discomfort arising from absolute bed rest', 'meals provided', Usage of hospital, perse', 'health team', in rank. 5) The nursing needs frequently pointed out were 'Nurses kindly explain of me the purpose, method, and results of the lab. test', 'Nurses sincerely pay attention to my word in communication'. The least nursing needs were 'Nurses observe my feces and whether I have constipation or not'. 'When I can't move, nurses help me by holding my arms or pulling my bed'. 6) The highest performed items were 'Nurses observe whether I bleed or not', and 'Nurses give me drug with exact dose in time'. The least performed items was about hospital environment, such as 'Temperature, ventilation & humidity in the room should be controlled'. 7) Besides religion that is related to nursing need with statistically significant difference, none of general characteristics were related to emotion, feeling of discomfort, and nursing needs.