• Korea Journal of Hospital Management
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• v.17 no.1
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• pp.1-22
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• 2012

This study tires to examine affects that job and socio-psychological stresses of female office workers influence job satisfaction, organization commitment, and leaving intentions. A complete data are collected by conducting a survey with 240 female office workers from 9 medical institutions regarded as almost general hospital in Seoul. It is analyzed that the relation between socio-psychological stress and job satisfaction, organization commitment, and leaving intentions by using t-test; analysis of variance; correlation analysis; principal component analysis; linear structural equation modeling; etc. The results of this study are summarized as following. First, as it was comprehended by specific characteristics of subjects that the female office workers' level of job and socio-psychological stress, job satisfaction, organizational commitment, and leaving intention, there were statistically significant distinctions from their age, marital status, presence of children, position in the organization, type of employment, and monthly average income. Second, this study regarded relationship between the female office workers' level of job and socio-psychological stresses, job satisfaction, organizational commitment, and leaving intention. Job and socio-psychological stresses were negatively correlated with job satisfaction and organizational commitment, but the stresses were positive with leaving intention. Third, after evaluating effect that 8 features related to the job stress could influence job stress, the most effective valuables were in order to unfairness in organizational structure, workplace culture, inadequate compensation, and relationship conflict. Fourth, when looking at the overall effects of the job and sociopsychological stresses on job satisfaction, organizational commitment, and leaving intention, work autonomy was the most influencing factor of work stress levels. The level of the job stress seemed to be a prevalent impact on the leaving intention and it showed the most negative relationship that path coefficient from leaving intention to organizational commitment and also from organizational commitment to job satisfaction. Based on these findings, it can be defined that the job and socio-psychological stresses strongly influence job satisfaction, organizational commitment, and leaving intention.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.1
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• pp.13-19
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• 2009

A 440MHz wireless and passive surface acoustic wave (SAW) based chemical sensor was developed on a $41^{\circ}YX\;LiNbO_3$ piezoelectric substrate for simultaneous measurement of $CO_2$ gas and relative humidity (RH) using a reflective delay line pattern as the sensor element. The reflective delay line is composed of an interdigital transducer (IDT) and several shorted grating reflectors. A Teflon AF 2400 and a hydrophilic $SiO_2$ layer were used as $CO_2$ and water vapor sensitive films. The coupling of mode (COM) modeling was conducted to determine optimal device parameters prior to fabrication. According to simulation results, the device was fabricated and then wirelessly measured using the network analyzer. The measured reflective coefficient $S_{11}$ in the time domain showed high signal/noise (S/N) ratio, small signal attenuation, and few spurious peaks. In the $CO_2$ and humidity testing, high sensitivity ($2^{\circ}/ppm$ for $CO_2$ detection and $7.45^{\circ}/%$RH for humidity sensing), good linearity and repeatability were observed in the $CO_2$ concentration ranges of $75{\sim}375ppm$ and humidity levels of $20{\sim}80%$RH. Temperature and humidity compensations were also investigated during the sensitivity evaluation process.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.4B
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• pp.323-338
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• 2003

The main memory database systems (MMDBMS) efficiently supports various database applications that require high performance since it employs main memory rather than disk as a primary storage. Recently, it has been increased needs that have the fast data processing as well as the efficient modeling of application requiring for a complicated structure, and conformity to applications that need the strict dta consistency. In MMDBMS, because all the data is located in the main memory, it can support the usable expression methods of data satisfying their needs without performance overhead. The method has the operation to manipulate the data and the constraint such as referential integrity in more detail. The data model consists of this methods is an essential component to decide the expression power of DBMS. In this paper, we discuss about various requests to provide the communication services and propose the data model that support it. The mainly discussed issues are 1) definition of the relationship between tables using the pointer, 2) navigation of the data using the relationship, 3) support of the referential integrity for pointer, 4) support of the uniform processing time for the join, 5) support of the object-oriented concepts, and 6) sharing of an index on multi-tables. We discuss the pointer-based data model that designed to include these issues to efficiently support complication environments.

• Journal of Aerospace System Engineering
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• v.12 no.1
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• pp.57-67
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• 2018

The APD (Antenna Pointing Driver) is an electronic equipment tool that is used to drive the two-axis gimbal-type antenna for the image data transmission of CAS (Compact Advanced Satellite). In this study, a heat dissipation of EEE (Electrical, Electronic and Electromechanical) is reviewed, to identify the parts that directly affected its efficiency, lifetime as well as the reliability of the structure. This event eventually incurs a failure of the EEE part itself, or even the entire satellite system as noted in experiments in this case. To guarantee reliability of electronic equipment during the mission, the junction temperature of EEE parts is considered a significant and important design factor, and subsequently must be secured within the allowable range. Therefore, the notation of the thermal analysis considering the derating is indispensable, and a proper thermal mathematical model should be constructed for this case. In this study, the thermal design and thermal analysis are performed to confirm the temperature requirement of the APD. In addition, we noted that the validity of the thermal model, according to each of the identified modeling methods, was therefore compared through the thermal analysis utilized in this case.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.574-582
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• 2018

In systems such as railways, automobiles, and airplanes, system malfunctions may lead to accidents, which often cause serious personal injury and economic loss. In previous studies, failure analysis has been performed, and safety measures derived using the component level information to reduce damage when a failure occurs. However, in functional safety concept, a focus is placed on lowering the frequency of occurrence of failures by performing risks analysis, setting up safety goals, and designing safety functions. Therefore, it is necessary to study how to determine the required safety function that can reduce the failure frequency to the acceptable level. To achieve this, we first studied a failure modeling method using SysML. It was then presented how several alternatives can be assessed to determine the desired safety function by simulating the generated SysML failure models and calculating the ability to reduce the failure frequency. A case study of a railway signaling system was done, demonstrating the effectiveness of the approach. We assessed whether the safety objectives were met for the alternative design of the railway signaling system through M & S. The results can be useful in that it can be applied from the early design phase and allow to choose the appropriate safety function that satisfies safety objectives among various design alternatives.

• Journal of Environmental Impact Assessment
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• v.28 no.3
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• pp.201-214
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• 2019

The concept of ecosystem services is important for the effective management of regional ecological resources. Multiple ecosystem services provided by regional ecosystems are represented as ecosystem service bundles, which define the co-occurrent ecosystem services in a specific region. Bundles provide useful information to identify regional characteristics of ecosystem services and categorize sub-regions with similar patterns of ecosystem service provision. We assessed eleven ecosystem services using modeling approaches and statistical data and produced bundles of cities in Gyeonggi-do.We also conducted principal component analysis and cluster analysis to categorize these cities according to the characteristics of ecosystem services. The results indicated that the cities in Gyeonggi-do were categorized into three groups depending on the types of provision,regulation, and cultural services, and were designated as urbanized, urban-forest, agriculture, or forest cities. These groups were influenced by land use patterns reflecting regional social-environmental features. The results provide useful information for identifying regional ecosystem services and facilitate decision-making in regional ecosystem service management.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.132-142
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• 2019

Purpose: The purpose of this finite element analysis study is to introduce the novel Lock screw system and analyze its mechanical property to see if it can prevent abutment screw loosening. Materials and Methods: The Lock screw is a component tightened on the inside of the implant abutment which applies compressive force to the abutment screw head. To investigate the effect, modeling was done using CAD program and it was analyzed by finite element analysis under various load conditions. First, the preload was measured according to the tightening torque of the abutment screw then it was compared with the theoretical value to verify the analytical model. The validated analytical model was then divided into those with no external load and those with 178 N, and the tightening torque of the lock screw was changed to 10, 20, 30 Ncm respectively to examine the property of stress distribution on the implant components. Results: Using Lock screw under various loading conditions did not produce equivalent stresses beyond the yield strength of the implant components. In addition, the axial load was increased at the abutment-abutment screw interface. Conclusion: The use of Lock screw does not exert excessive stress on the implant components and may increase the frictional force between the abutment-abutment screw interface, thus it is considered to prevent loosening of the abutment screw.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.116-126
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• 2021

Ground Component Command (GCC) has been developing operational planning and execution systems to implement "Decisive Integrated Operations", which is the concept of ground operations execution, and achieved remarkable results. In particular, "Simultaneous Offense-Defense Integrated Operations" is developed mainly to neutralize enemies in deep areas and develop favorable conditions for the allies early by simultaneously attacking and defending from the beginning of the war. On the other hand, it is limited to providing scientific and reasonable support for the commander's decision-making process because analyzing the effects of the deep operation with existing M&S systems is impossible. This study developed a model for analyzing the effects of deep operations that can be used in the KJCCS. Previous research was conducted on the effects of surveillance, physical strike, and non-physical strike, which are components of deep operations to find the characteristics and limitations and suggest a research direction. A methodology for analyzing the effects of deep operations reflecting the interactions of components using data was then developed by the GCC, and input data for each field was calculated through combat experiments and a literature review. Finally, the Deep operations Effect CAlculating Model(DECAM) was developed and distributed to the GCC and Corps battle staff during the ROK-US Combined Exercise. Through this study, the effectiveness of the methodology and the developed model were confirmed and contribute to the development of the GCC and Corps' abilities to perform deep operations.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.11-21
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• 2022

All-solid-state batteries are one of the promising candidates for next-generation batteries and are drawing attention as a key component that will lead the future electric vehicle industry. This study analyzes 10,280 comments on Reddit, which is a global social media, in order to identify policy issues and public interest related to all-solid-state batteries from 2016 to 2021. Text mining such as frequency analysis, association rule analysis, and topic modeling, and sentiment analysis are applied to the collected global data to grasp global trends, compare them with the South Korean government's all-solid-state battery development strategy, and suggest policy directions for its national research and development. As a result, the overall sentiment toward all-solid-state battery issues was positive with 50.5% positive and 39.5% negative comments. In addition, as a result of analyzing detailed emotions, it was found that the public had trust and expectation for all-solid-state batteries. However, feelings of concern about unresolved problems coexisted. This study has an academic and practical contribution in that it presented a text mining analysis method for deriving key issues related to all-solid-state batteries, and a more comprehensive trend analysis by employing both a top-down approach based on government policy analysis and a bottom-up approach that analyzes public perception.

• Asia Marketing Journal
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• v.8 no.1
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• pp.105-132
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• 2006

The major purpose of this study is to investigate the impact of environmental uncertainties and logistics resources capabilities mediated by relational norms and logistics services on logistics performance in the industrial products. The 272 data were collected from the key informants who were working at the logistics-related departments in the H Heavy Industries & Construction and HSD Engine. The following results were verified using structural equation modeling. First, environmental uncertainties such as dynamism and heterogeneity unexpectedly had insignificant effects on relational norms such as information exchange and flexibility and logistics services such as product availability and on-time delivery. Second, logistics resource capabilities showed unique effects based upon its component's characteristics. For example, Logistics Information Systems did not have direct impact on logistics services but had indirect effect on logistics services via relational norms. On the other hand, logistics resources such as logistics specific assets and transportation service competencies had direct impact on logistics services but not on relational norms. Third, relational norms between transaction partners significantly affected logistics services but had insignificant effects on logistics performance such as logistics costs reduction and delivery qualities. Fourth, consistent with several studies, excellent logistics services between industrial purchaser and suppliers based upon relational norms did have significant effect on logistics performance such as delivery consistency and delivery qualities. Finally, the empirical results in this study could be strategic logistics management guidelines based upon the theoretical relationships among the environmental uncertainties, logistics information systems, logistics resources, relational norms, logistics services, and logistics performance.