• Journal of Convergence for Information Technology
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• v.9 no.2
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• pp.34-42
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• 2019

In this study, we analyzed the effects of the automatic control system on the reactor operation. The Propyrene Reactor process is complex and typically is inefficient and costly due to the lack of productivity. In this study, a research model was presented with the aim of supplementing obstacles to enhance operational efficiency and increase productivity. The configuration of the existing processes was analyzed to complement the hardware and software systems with original models. The composition of the facility is applied to eight reactor units producing 600,000 ton/year propylene per year. As a result of applying the research model, efficiency of operation was increased, and production volume increased from 90 to 95%, along with 91% Reliability. Future studies will present a research model to improve productivity by 100 percent. In addition, we will study the stability and productivity improvement of PSA (Pressure Swing Adsorption) systems, which are the hydrogen production process of propylene by-products.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.5
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• pp.27-38
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• 2007

One of the most important security issues of e-mail service is user privacy. Currently, various security protocols, like PGP(pretty Good Privacy), S/MIME(Secure/Multipurpose Internet Mail Extension), have been proposed. These protocols, however, do not provide forward secrecy. Recently, some security protocols that provide forward secrecy were proposed. But all of them require changes to the current e-mail infrastructure. Moreover, contrary to authors' intention, some of them do not actually provide perfect forward secrecy. In this paper, we propose a new practical e-mail security protocol. The proposed protocol provides perfect forward secrecy and uses a practical e-mail model that dose not require any changes to existing e-mail servers. It encrypts and authenticates messages efficiently using elliptic curve based signcryption scheme. In addition, we provide a way to send secure group e-mails.

• Journal of Industrial Convergence
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• v.22 no.10
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• pp.37-45
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• 2024

This study aims to compare and analyze the functionality and efficiency of 3D generation AI platforms to evaluate their practical applicability in the 3D content creation process and suggest improvement directions. A total of nine platforms were researched using search, and four platforms were selected based on their utilization of the latest technology, compatibility, and user accessibility. We used the same prompts to create 3D objects on each platform and analyzed the results, focusing on whether they were customizable, beneficial for creating immersive content, efficient in production, free to test, or good value for money. The results showed that Meshy and Tripo performed well with fast generation speeds and efficient polygon optimization, while Spline offered a wide range of media application capabilities but was limited in quality. We found that different 3D generation AI platforms are suitable for different production pipelines and user needs. This study provides practitioners interested in 3D content creation with a practical guide for platform selection and provides insights into the future direction of 3D generative AI technology, which will contribute to future research and industrial applications.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.2
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• pp.43-53
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• 2017

This study aims to analyze the effect of typhoons on pear production. Pears are typical fruits that are vulnerable to typhoon damages, so typhoons are negatively associated with pear productivity. However, relatively less pear damages by typhoons in the main pear production area, comparing to the average in Korea, have been reported. The main production area seems to adopt better agricultural techniques or practices to cope with natural disasters such as typhoons. Thus, this study tests the hypothesis that there are differences of production losses due to typhoons between the main pear production area and the rest using the stochastic frontier analysis. The main production area is defined by Location Quotient Index (LQI), and we found that LQI had a significant effect to decrease the productivity losses in the main production areas, which shows that those production areas alleviated the pear production loss due to typhoons.

• Journal of Oral Medicine and Pain
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• v.35 no.2
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• pp.135-147
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• 2010

In this study, the objective masticatory efficiency of two groups of temporomandibular disorder patients, pain and sound groups, was compared with that in a normal group using the MAI (mixing ability Index). The subjective chewing ability was evaluated using questionnaires, such as the Food Intake Ability Index (FIA) and Visual Analogue Scale (VAS). The Oral Health Impact Profile (OHIP)-49K of the patients was also examined to measure the oral health-related quality of life. The results were as follows: 1. The MAI, FIA and VAS in the pain group were significantly lower than in the normal and sound groups. This shows that the chewing efficiency of the pain group was lower than the normal and sound groups (P<0.05). However, there was no significant difference between the sound and normal groups. 2. The OHIP-49K for the oral health-related quality of life showed a significant increase in both the pain and sound groups compared with normal group. This means that the oral health-related quality of life was lower in both the pain and sound groups. 3. There was a correlation between the MAI, FIA and VAS (P<0.01) in all subjects (71 persons). The OHIP-49K was associated with the FIA and VAS. 4. There was a correlation between the FIA and VAS (P<0.05) in the sound group but no correlation in the other groups. 5. There was a correlation between the FIA and VAS in all groups. 6. The VAS was increased significantly in the pain group according to the level of pain reduction after treatment (P<0.05). However, there was no significant increase in the MAI, even though there was an improvement in masticatory efficiency. In addition, there was no difference in the FIA and OHIP-49K according to the level of pain reduction after treatment. In this study, it is believed that pain is a main factor decreasing the masticatory efficiency in patients with temporomandibular disorders. Moreover, TMJ sounds decrease the quality of life but do not decrease the masticatory efficiency. Therefore, it is important to control the pain in order to improve the masticatory efficiency in temporomandibular disorder patients. Moreover, managing both pain and sound can improve the quality of life.

• Korean Journal of Social Welfare
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• v.52
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• pp.117-141
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• 2003

This study is to identify the efficiency in Busan social welfare agencies between input factors and output factors. For this purpose, gathered are the 2001 services reports of those study agencies. This study used 4 difference model, model 1; comparing input factor(social worker number & labor cost) about output factor(the total number of program used person), model 2; comparing input factor(the total number of social welfare agencies staff & the total working expenses) about output factor(the total number of program used person), model 3; comparing input factor(the total number of volunteer, social welfare agencies staff & a period of operation) about output factor(the total number of program used person), model 4; comparing input factor(the total number of volunteer, social welfare agencies staff, a period of operation & the total working expenses) about output factor(the total number of program used person). Charnes's study(1978) provided an analytical tool for efficiency services output of non-profit organizations, and DEA(Data Envelopment Analysis) was a analytical framework for evaluating the impact of social service outcome. the finding are as follows : (1) In the results of comparing 4 models as same standard, we can find 35-55%(16-25) efficiency agencies among the 45 social welfare agencies. (2) For all DMU becoming the efficiency 1 to standard of output factor, model 1; 33 agencies are increasing the social worker number($\Delta$0.8 number), 10 agencies are raising the labor cost of social worker($\Delta$1,189,000 Won), model 2; 30 agencies are increasing the total number of social welfare agencies staff($\Delta$1.25 number), 14 agencies are raising the total working expenses($\Delta$1,447,000 Won), model 3; 8 agencies are increasing the total number of social welfare agencies staff($\Delta$2.26 number), 14 agencies are increasing the total number of volunteer($\Delta$52 number), and 10 agencies are increasing a period of operation($\Delta$13 month), model 4; 24 agencies are increasing the total number of social welfare agencies staff($\Delta$1.8 number), 12 agencies are raising the total working expenses($\Delta$5,017,000 Won), 12 agencies are increasing the total number of volunteer($\Delta$43.2 number), and 23 agencies are increasing a period of operation($\Delta$16 month).

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.6
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• pp.195-208
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• 2022

The role of venture CEO and their intrinsic capabilities on organizational performance can be determined by the level of resource synchronization initiated by the focal managers. Despite the important role of venture CEOs, a systematic lack of in-depth theoretical and empirical studies on ruminating the relationship between the effects of a CEO's capabilities and organizational performance depending on the level of resource synchronization exist for the rationale of investigation. To supplement the limitations of previous studies, this research empirically analyzes the role of managers specifically synchronizing organizational resources that affect organizational performance in the professional sports industry. Based on the entrepreneurship theory and resource-based view (RBV), this research conceptualizes the roles of venture CEO and basketball head coach in the professional sports industry as very similar in terms of organizational structure and performance mechanism embedding entrepreneurial characteristics necessary for managing organizational resources. In this research, we hypothesized (1) organizational resource synchronization will mediate the positive relationship between the ability of professional basketball head coach and organizational performance and (2) the indirect effect of the professional basketball head coach's capabilities on organizational performance mediated by resource synchronization will be moderated by the capabilities of players. To test these hypotheses, we utilized the PROCESS macro model 58 with the empirical data of 9 seasons (2013~2014-2021~2022) of 30 National Basketball Association (NBA) and 10 Korean Basketball League (KBL) teams. The statistical results showed that (1) resource synchronization mediates the positive relationship between professional basketball head coach capabilities and organizational performance and (2) the capabilities of players moderated the indirect effects of the abilities of head coaches on team performance via resource synchronization. This paper contributes to both academic and practical domains of entrepreneurship by empirically testing the research model through objective professional sports data.

• The Journal of Engineering Geology
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• v.25 no.1
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• pp.131-148
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• 2015

The purpose of this study is to analyze and compare the heat transfer efficiency of using copper pipe, stainless pipe and traditional PE pipe commonly used for geothermal heat exchanger, with aims at seeking improved methods. In addition, the varying efficiency of heat transfer from ground heat and groundwater heat was assessed and its applicability was discussed. Design parameters for empirical field study were derived by controlling flow rate, velocity and caliber of pipes of the heat exchanger after the thermal efficiency of the heat exchanger material was evaluated. The heat exchange efficiency and effective thermal conductivity were measured with changing pattern through field thermal efficiency and thermal response test. Experimental results show that the metal material showed higher heat transfer efficiency than the PE pipe. Although the heat transfer efficiency was not high with the increase of the pipe diameter in the flow rate, it was high with the increase of the pipe diameter in the velocity.

• Journal of radiological science and technology
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• v.29 no.3
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• pp.167-175
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• 2006

With the recent prevalence of helical CT and multi-slice CT, which deliver higher radiation dose than conventional CT due to overbeaming effect in X-ray exposure and interpolation technique in image reconstruction. Although multi-detector and helical CT scanner provide a variety of opportunities for patient dose reduction, the potential risk for high radiation levels in CT examination can't be overemphasized in spite of acquiring more diagnostic information. So much more concerns is necessary about dose characteristics of CT scanner, especially dose efficient design as well as dose modulation software, because dose efficiency built into the scanner's design is probably the most important aspect of successful low dose clinical performance. This study was conducted to evaluate z-axis geometric dose efficiency in single detector CT and each level multi-detector CT, as well as to compare z-axis dose efficiency with change of technical scan parameters such as focal spot size of tube, beam collimation, detector combination, scan mode, pitch size, slice width and interval. The results obtained were as follows ; 1. SDCT was most highest and 4 MDCT was most lowest in z-axis geometric dose efficiency among SDCT, 4, 8, 16, 64 slice MDCT made by GE manufacture. 2. Small focal spot was 0.67-13.62% higher than large focal spot in z-axis geometric dose efficiency at MDCT. 3. Large beam collimation was 3.13-51.52% higher than small beam collimation in z-axis geometric dose efficiency at MDCT. 4. Z-axis geometric dose efficiency was same at 4 slice MDCT in all condition and 8 slice MDCT of large beam collimation with change of detector combination, but was changed irregularly at 8 slice MDCT of small beam collimation and 16 slice MDCT in all condition with change of detector combination. 5. There was no significant difference for z-axis geometric dose efficiency between conventional scan and helical scan, and with change of pitch factor, as well as change of slice width or interval for image reconstruction. As a conclusion, for reduction of patient radiation dose delivered from CT examination we are particularly concerned with dose efficiency of equipment and have to select proper scanning parameters which increase z-axis geometric dose efficiency within the range of preserving optimum clinical information in MDCT examination.

• Journal of the Korea institute for structural maintenance and inspection
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• v.9 no.2
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• pp.113-120
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• 2005

The purpose of this study is to suggest a method of concrete safety inspection management system for safety inspection. this research investigates the process of building safety inspection with IDEF0(Integration DEFinition) process modeling method, focusing on concrete durability inspection, and then suggests a data management system, which allows user communications between site and related unit with RDBMS(Relational Database Management System). The suggested system is expected to provide more efficient data sharing tools and consequently improve safety inspection's quality.