• Journal of the Microelectronics and Packaging Society
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• v.19 no.1
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• pp.67-73
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• 2012

After flash memory card(FMC) was manufactured by $B^2it$ process, interfacial reaction of silver bump with thermal stress was studied. To investigate bonding reliability of Ag bump, thermal shock and thermal stress tests were conducted and then examined on the crack between Cu land and Ag bump interface. Diffusion reaction of Ag bump/Cu land interface was analyzed using SEM, EDS and FIB. The Ag-Cu alloy layer due to the interfacial reaction was formed at the Ag/Cu interface. As the diffusivity of Ag ${\rightarrow}$ Cu is faster than Cu ${\rightarrow}$ Ag, a lot of (Cu, Ag) alloy layers were observed at the Cu layer than Ag. These alloy layers contributed to increase the Cu-Ag bonding strength and its reliability.

• Journal of Korea Entertainment Industry Association
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• v.13 no.1
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• pp.99-109
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• 2019

The study was conducted to investigate the activities of working people in the sports club. The subject of this study was to take samples of workers who participated in the physical education system using the convenience sampling method. Out of a total of 400 questionnaires, 387 were used for research purposes, except for invalid or error questionnaires. Factor analysis and reliability tests were performed using IBM SPSS statistics Ver 21.0. Frequency analysis was conducted to explore the general characteristics of the study participants. An independent sample t-test ANOVA were conducted to verify differences among groups according to demographic characteristics, and a correlation analysis was conducted to examine the relationship between variables. Regression was performed to verify the effect of variable factors. The results of the study are as follows. First, there was no difference in wellness and job satisfaction according to gender. Second, there was no difference in wellness and job satisfaction according to sport. Third, there was a significant difference intellectual wellness according to age. In particular, 40s and 50s were higher than 60s and over. Fourth, there was a significant difference in social wellness according to activity duration. In particular, 1~2 years were higher than 3 years or more. Finally, If you look at the impact of working people's wellness lifestyle sports club activities on job satisfaction, the professional wellness lifestyle club activities showed significant influence on job satisfaction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1C
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• pp.107-115
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• 2005

ATC (Abnormal traffic controller) is presented as next generation security technology to securely support reliable Internet service and to guarantee network survivability, which is deployed in Internet access point. The key concept of the ATC is abnormal traffic monitoring and traffic control technology. When fault factors exist continuously and/or are repeated, abnormal traffic control guarantees service completeness as much as possible. The ATC with control policy on abnormal traffic is superior to the ATC with blocking policy as well as conventional network node, when the ratio of effective traffic to abnormal traffic is higher than $30{\%}.$ When traffic intended unknown attack occurs, network IDS is high false positive probability and so is limited to apply. In this environment, the ATC can be a key player to help the network node such as router to control abnormal traffic.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.781-788
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• 2021

This paper is the study of a design to eliminate the communication error that occurs between the main controller and the servo controller of the K56 ammunition-carrying armored vehicle. The K56 assists in the operation of the K-55A1 self-propelled gun by automating the supply and loading of ammunition. The CAN communication board of the ammunition carrier is a key-function product mounted inside the main controller and installed for communication with the servo controller. It was confirmed that an undefined error would occur intermittently in the existing CAN communication board, interrupting the operation of the ammunition supply system during the loading process. In this paper, in order to solve the problem, the cause of the failure is identified through analysis and a functional test of the communication signal between the main controller and the servo controller. The error was resolved by redesigning and improving the Read/Write algorithm. Finally, the proposed cause analysis and design effectiveness were verified through the CAN communication board single item test and a system equipment application test. It is expected that this study will serve as a reference for improving defense capabilities through improving the reliability of CAN communication boards and by improving the reliability of the overall electronic equipment using DPRAM.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.1
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• pp.1-16
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• 2023

Recently, the shift to next-generation wide-bandgap (WBG) power semiconductor for electric vehicle is accelerated due to the need to improve power conversion efficiency and to overcome the limitation of conventional Si power semiconductor. With the adoption of WBG semiconductor, it is also required that the packaging materials for power modules have high temperature durability. As an alternative to conventional high-temperature Pb-based solder, Ag sintering die attach, which is one of the power module packaging process, is receiving attention. In this study, we will introduce the recent research trends on the Ag sintering die attach process. The effects of sintering parameters on the bonding properties and methodology on the exact physical properties of Ag sintered layer by the realization 3D image are discussed. In addition, trends in thermal shock and power cycle reliability test results for power module are discussed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.1
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• pp.95-107
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• 2016

Ground water is one of important parameters in the designs of underpass structures because urban areas are characterized by soil ground which is relatively permeable than rock ground and a high level of ground water due to low elevation. Therefore, it is important properly to predict variations of the ground water when they can affect underpass structures. In this study, a series of numerical analyses are performed to predict the variations of ground water levels considering the degree of surface imperviousness and LID(Low Impact Development) application. In turn the stability of underground structure is assessed using predicted ground water level. The results show that an increase in the impervious surface area decreases the ground water level. The application of permeable pavement as a LID facility increases the ground water level, improving the infiltration capacity of rainfall into the ground. Seasonal variations of the ground water level are also verified in numerical simulation. The results of this study suggest that reasonable designs of underpass structures can be obtained with the suitable prediction and application of the ground water level considering the surface characteristics.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.355-360
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• 2006

Function analysis and idea creation phase in Value Engineering(VE) Process is applied to manufacturing Industry for developing functions for elements of products, and in construction come to use various components like process, size of project, spaces as well as function itself due to multi-functional aspect. For this reason, VE applications to the construction industry are considered to be less frequent and efficient than to the manufacturing. To resolve this problem, a new technique of Function Integration Fast(HI FAST) and Hierarchical Value Engineering Concept Modules(HVECM) was made for practical integration and sequence of VE job Plan. Two types of function would be defined In this method, first and second function, during the job Plan process, and two function champions be selected for next creation phase process. For verification of consecutiveness of function analysis and idea creation phase for successful VE project implementation, this methodology was tested under design phase in office and IT Multi-functional building project. Make sure the successful application of this process with this method, need to develop the talent of VE experts and team members for process of function analysis and creation phase.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.1
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• pp.29-35
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• 2006

The third generation mobile communications system requiring the reliable multimedia data transmission has provided with the reliable voice, data and video services over the variable propagation environment. However the broadband wireless multiple access technologies cause Inter Symbol Interference(ISI) or Multiple Access Interference(MAI) to degrade the performance of CDMA(Code Division Multiple Access) system. Constant Modulus Algorithm which is frequently used as the adaptive blind equalizers to remove the interfering signal has ill-convergence phenomenon without proper initialization. In this paper, new blind equalization method based on conventional CMA is proposed to improve the channel efficiency, and through computer simulation this is tested over the time varying fading environment of mobile communication system. consequently, new blind equalization method into concatenated Kalman filter with CMA is verified better than conventional CMA through adopting minimum mean square errors and eye-pattern obtained from algorithm are compared.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.7 no.1
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• pp.15-22
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• 2007

The third generation mobile communications system requiring the reliable multimedia data transmission has provided with the reliable voice, data and video services over the variable propagation environment. However the broadband wireless multiple access technologies cause Inter Symbol Interference(ISI) or Multiple Access Interference(MAI) to degrade the performance of CDMA(Code Division Multiple Access) system. Constant Modulus Algorithm which is frequently used as the adaptive blind equalizers to remove the interfering signal has ill-convergence phenomenon without proper initialization. In this paper, new blind equalization method based on conventional CMA is proposed to improve the channel efficiency, and through computer simulation this is tested over the time varying fading environment of mobile communication system. consequently, new blind equalization method into concatenated Kalman filter with CMA is verified better than conventional CMA through adopting minimum mean square errors and eye- pattern obtained from algorithm are compared.

• The Journal of the Korea Contents Association
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• v.16 no.7
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• pp.50-62
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• 2016

The aim of this study was to develop scale of test taker to affect on process of selection of college. The study procedures were performed as follow : establish of study model, item generation, verification of content validity, 1st and 2nd pilot test and verification of construct validity and reliability. In order to verification of validity and reliability, 230 freshman were surveyed and the data were analyzed by mean, standard deviation, skewness. kurtosis, Pearson correlation, Verimax factor analysis and Cronbach's ${\alpha}$. As result of factor analysis, the 15 factors(61 items) that explain 68.37% of the total variance were extracted and each factors were classified by attribution as follow : Information collection-mass media(4items), college activity (3items), support and environment(4items), education(5items), Influential person on decision making(3items), education quality(4items), education service(5items), reputation(3items), accessibility(2items), personal circumstances(2items), college's mass media(5items), promotion (4items), on-line(4items), person's PR (3items), College image(10items). Cronbach's ${\alpha}$ of total items was 0.916 and Cronbach's ${\alpha}$ of each factors were showed range between 0.694~0.878. Measurement scale of this study may be utilized to collect basic data be required to establish policy strategy of local college be faced with difficulty of admission recruitment.