• The Journal of the Acoustical Society of Korea
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• v.43 no.2
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• pp.214-224
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• 2024

Sonobuoys are disposable devices that utilize sound waves for information gathering, detecting engine noises, and capturing various acoustic characteristics. They play a crucial role in accurately detecting underwater targets, making them effective detection systems in anti-submarine warfare. Existing sonobuoy deployment methods in multistatic systems often rely on fixed patterns or heuristic-based rules, lacking efficiency in terms of the number of sonobuoys deployed and operational time due to the unpredictable mobility of the underwater targets. Thus, this paper proposes an optimal sonobuoy placement strategy for Unmanned Aerial Vehicles (UAVs) to overcome the limitations of conventional sonobuoy deployment methods. The proposed approach utilizes reinforcement learning in a simulation-based experimental environment that considers the movements of the underwater targets. The Unity ML-Agents framework is employed, and the Proximal Policy Optimization (PPO) algorithm is utilized for UAV learning in a virtual operational environment with real-time interactions. The reward function is designed to consider the number of sonobuoys deployed and the cost associated with sound sources and receivers, enabling effective learning. The proposed reinforcement learning-based deployment strategy compared to the conventional sonobuoy deployment methods in the same experimental environment demonstrates superior performance in terms of detection success rate, deployed sonobuoy count, and operational time.

• The Journal of the Korea Contents Association
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• v.16 no.3
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• pp.354-365
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• 2016

The purpose of the study was to identify and compare levels of recognition of empowerment, job satisfaction, organizational commitment between Advanced Practice Nurses(APN) and Registered Nurses(RN) of hospitals. Data collection was done by the 85 APN and 120 RN of six large hospitals, four medium sized hospitals in Seoul and Incheon. T-test and ANOVA using SPSS 18.0 were performed. There were no significant differences of empowerment between APN($3.56{\pm}0.53$) and RN($3.50{\pm}0.54$)(t =-. 861, p = 0.390). job satisfaction between APN($3.36{\pm}0.53$) and RN($3.25{\pm}0.46$)(t =- 1.575, p = 0.117), organizational commitment between APN($3.11{\pm}0.34$) and RN($3.05{\pm}0.36$)(t =- 1.301, p = 0.195). Empowerment, job satisfaction, organizational commitment of APN and RN showed no significant differences. There are some reasons why it resulted in no significant difference between APN and RN. APN's role in Korea is not clearly established and distinguished from RN, lack of appropriacy of employment and reward, and lack of the institutional foundation for APN's operation and efficiency.

• Korean Journal of Poultry Science
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• v.29 no.1
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• pp.37-43
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• 2002

This experiment was conducted to study the effect of early-life feed restriction with diet dilution on compensatory growth, feed efficiency and abdominal fat pad deposition in broilers. In this study, the chicks were randomly assigned to five treatments. Twenty chicks were assigned to each floor pen, and each dietary treatment was replicated with three pens. Birds In control group (C) were full-fed a starter diet throughout the experimental period, and all birds in four dietary treatments (T1-T4) were fed as starter diet diluted with 50% rice hulls. Birds in T1 were fed with a diluted starter diet ad libitum from 7- to 74-d. In T2,the feeding program was 1-d withdrawal alternating with 3-d feed and in T3 1-d withdrawal alternating with 2-d feed. The feeding Program in T4 was alternate days withdrawal and feeding. The feeding with the diluted starter diet (T1) did not significantly affect to growth rate as compared to the birds of C. When periods of 24 h feed withdrawal were Imposed in conjunction with the diluted diets, birds were under weight at 49 d. As the diluted diet treatment was combined with feed withdrawal (T2-T4), there were further less growth. During the 22 to 49 d Period,T1 birds had greater weight gain compared to other treatments (P<0.05) . Birds consumed less feed from 7- to 49-d when the rice hull dilution was used, and this effect was increased by imposition of feed withdrawal (P<0.07) . If rice hull was excluded from the calculation of feed intake (assumed indigestible) then Intake of the starter diet was markedly less for restricted vs. control birds. After 22 d and from 7 to 49 d, restricted birds had superior feed conversion (P<0.05) compared to control birds. Abdominal fat pad deposition and mortality were not influenced by early feed restriction by diluted diet (P<0.05) .

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.389-399
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• 2016

The purpose of this study was to provide the evidence necessary to establish job stress management strategies to improve office workers conditions by looking at the impact on job stress factors depending on the nature of the organization. The stress related variables (job stress and psychological well-being) and organizational effectiveness variables (job satisfaction, job engagement, intention to leave, and presentieesm) was included. A total of 154 questionnaires were distributed from 26th June to 1 August 2014 and 150 people were analyzed. The results indicated that a lack of reward was negatively correlated with job satisfaction and job engagement, and positively correlated with the intention to leave (p<0.05) in a large-sized company model. Moreover, in a medium-sized company model, organizational injustice was statistically significant with job satisfaction and job engagement. Organizational injustice, lack of reward, and occupational climate was positively correlated with the intention to leave (p<0.05). This study has its significance in that it looked at the job stress as a predictive variable to explain the organizational effectiveness and highlights the need to establish a stress management strategy depending on the nature of the company.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.612-627
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• 2020

This is a case study of Korea Airports Corporation(KAC) examining the effects of pre- and post-employment experience factors on individual and organizational priority. This study surveyed 240 employees of KAC and analyzed the results. The influence of pre-employment experience (number of times applying to public sector, reason to choose public sector, and job changing experience) and post-employment experience (years of employment, position, and job types) on personal value (authority, achievement, welfare, vacation, and personal life) and organizational value (responsibility, obligation, performance, compensation, and participation) was studied. The results indicated that organizational value is generally greater than personal value. Preference value (=organizational value/personal value) was greater than one for every group. Education, years of employment, position, reason to choose public sector were confirmed to influence preference value. For pre-employment factors, as an employee chooses to work in the public sector because of better balance of work-personal life, preference value was confirmed to be lower. For post-employment factors, when the years of employment are longer and the position is higher, preference value is significantly higher. The results imply that an organization should establish a fair evaluation and compensation system to help employees display their full capability to produce maximum performance.

• Management & Information Systems Review
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• v.37 no.3
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• pp.115-130
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• 2018

The purpose of this study is to clarify the relationship between organizational characteristics and information systems characteristics or job satisfaction, attempts to examine the regulatory effects brought about by the adjustment of social capital theory. So far, The results of this study are based on the analysis of individual models from the perspectives of each functional organization such as HR, organization, finance, operation, and MIS. Therefore, this paper attempted a comprehensive analysis of factors affecting job satisfaction and firm performance by presenting an integrated research model of organizational perspectives in addition to the approach of MIS perspective. The characteristics of information system were promptness, CEO support, and compensation. And the organizational characteristics were multiple regression analysis using innovation, trust, and preferential factors. The analysis data is based on sixth data from the HCCP of Korea Productivity Center. According to the analysis results, all the variables had a significant influence on satisfaction, especially CEO support and trust. The analysis of the moderating effect between innovation and job satisfaction was moderated by vision sharing. Only the logistic regression analysis of the satisfaction with the average salary of the members among the demographic variables was statistically significant. Therefore, this study can be concluded that the overall satisfaction level will be improved by recognizing appropriate compensation as sufficient compensation.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.289-293
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• 2011

This study was conducted to develop economic injury level (EIL) of onion thrips, Thrips tabaci, on welsh onion (Allium fistulosum L. var) in the early transplanting stage. The changes of welsh onion biomass, yield loss, and T. tabaci density were investigated according to the inoculation periods of T. tabaci. In the early transplanting stage of welsh onion, the yield loss (%) increased with increasing inoculation periods: 17.0, 53.3, 38.4, and 80.8% yield loss in 5, 10, 15, and 20 d inoculation periods, respectively. The relationship between Cumulative Insect Days (CID) of T. tabaci and yield loss (%) of welsh onion was well described by a nonlinear logistic equation. Using the estimated equation, EIL of T. tabaci on welsh onion was estimated to 30 CID per plant based on the yield loss 12% (an empirical gain threshold 5% + marketable rate 93% of welsh onion). ET was calculated to 24 CID, which corresponds to 80% of EIL. Until a more defined EIL-model is developed, the present results should be useful for T. tabaci management in early growth stage of welsh onion. The effect of T. tabaci attack on the yield of welsh onion in late growing season (120 days after transplanting) was also examined. The yield of welsh onion increased at a low population density of T. tabaci and decreased at higher densities, showing a typical over-compensatory response.

• Journal of Science Education
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• v.35 no.1
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• pp.68-79
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• 2011

The purpose of this study was to investigate the recognition of middle school students on 'Thinking Science' activities and the influence on the understanding of the gas particles behavior concepts. For this study 125 students of four classes first grade in middle school were divided into two groups, the experimental and the control group. The SRT II test was carried out to identify the cognitive level of the students. The logical factors, needed to understand of the gas particles behavior concepts, were extracted. And the 9 'Thinking Science' activities designed to develop these factors were chosen and then implemented to the students of the experimental group. After the lesson for the gas particles behaviors, the achievement test of understanding of the gas particles behavior concepts and the survey of the students' recognition on 'Thinking Science' activities were administered. According to the results of the achievement test, there was not significant difference between the two groups on the whole. But only mature concrete operational students in the experimental group got high scores than those in the control group in analyzing the effect size. According to the results of the ANCOVA analysis, there was significant difference between the two girls' group. When students in the experimental group had a positive perceptions about 'Thinking Science' activities, they got higher achievement scores. This implied that there was a correlation between perception about 'Thinking Science' activities and their achievement in the gas particles behavior concepts. Especially, students with positive perception in mature concrete operational period got higher scores in science achievement. After the 'Thinking Science' activities, there was a high perceptions about improving in scientific thinking.

• Culinary science and hospitality research
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• v.22 no.3
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• pp.66-78
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• 2016

The purpose of this study was to provide hotel bakery organizations with useful information for human resources management based on a substantial clarification of the relationship and correlation of hotel bakery employees' self-leadership, self-efficacy, and organizational commitment. Resources were gathered from June 20, 2015 to July 10, 2015 by distributing a total of 500 surveys, from which 377 were collected. Excluding 23 survey forms not suitable for the analysis, 354 survyes were processed through factor analysis, reliability test, and multivariant structural analysis using SPSS 18.0 and AMOS 18.0 to verify the hypotheses. The findings of the analysis can be summarized as follows: first, behavior-centered strategies, natural compensation, and constructive thinking strategies had a significantly positive impact on self-efficacy. Second, in the analysis of impact of self-efficacy on organizational commitment, it was significant for emotional immersion, but did not have a significantly positive impact on normative immersion. Third, in the relationship between self-leadership and organizational commitment, behavior-centered strategies and natural compensation did not have a significant impact on emotional immersion. However, constructive thinking strategies had a significant impact. The following implications can be derived based on the above findings: this study implies the possibility of future studies on the variables of self-efficacy as it set behavior-centered strategies, natural compensation, and constructive thinking strategies as the preliminary factors under hotel bakery employees' self-leadership; and it analyzed the causality of each factor with emotional immersion and normative immersion as the subordinate factors of self-efficacy and organizational commitment to show that self-leadership and self-efficacy of hotel bakery employees based on emotional immersion and normative immersion can stably improve the organization of hotel bakeries.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.357-366
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• 2014

This study has been implemented to explore the method to improve job satisfaction and service quality of its staff by figuring out the effect of job satisfaction of geriatric hospital staff on service quality. For this reason, we conducted a questionnaire survey on April 2 to May 22, 2013 to target 300 people ten geriatric hospital workers in Busan Metropolitan City area, was utilized to study the final total of 276 parts. Firstly, It was found that work satisfaction, wage satisfaction and colleague satisfaction have an effect on job satisfaction, and Secondly, satisfaction and fellow satisfaction of business, were analyzed to affect, but had no effect conservative satisfaction Thirdly, for the effect of job satisfaction on the service quality, it was found that job satisfaction has an effect on service quality. Therefore, it can be concluded that service quality for patients can be improved only if job satisfaction of staff is improved, and by reducing stress caused by overwork of staff and boosting their morale through reasonable wage and compensation.