• The KIPS Transactions:PartC
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• v.9C no.3
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• pp.375-384
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• 2002

In the current Internet, the QoS of interactive applications is hardly guaranteed because of variable bandwidth, packet loss and delay. Moreover, VoIP which is becoming an important part of the information infra-structure in these days, is susceptible to network packet loss and end-to-end delay. Therefore, it needs error control mechanisms in network level or application level. The FEC-based error control mechanisms are used for interactive audio application such as VoIP. The FEC sends a main information along with redundant information to recover the lost packets and adjusts redundant information depending on network conditions to reduce the bandwidth overhead. However, because most of the error control mechanisms do not consider end-to-end delay but packet loss rate, their performances are poor. In this paper, we propose a new error control algorithm, SCCRP, considering packet loss rate as well as end-to-end delay. Through experiments, we confirm that the SCCRP has a lower packet loss rate and a lower end-to-end delay after reconstruction.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.314-318
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• 1984

China has made rapid strides in agricultural production during the past few years. Although the absence of any serious climatic disturbances is a contributing factor, implementation of the responsibility system to reward peasant families for their initiatives has been by far the most significant. This has resulted in increased specialization, a greater requirement for technical adivsory services, and a much higher demand for farm equipment and production inputs. The revamped system has brought with it some problems such as differences in income between the most progressive producers and their less successful neighbours and urban workers, a shortage of storage, transport and processing facilities, and a strain on the national treasury to continue to subsidize farm prices. Demand for fertilizers has been increasing at a fast rate, especially for nitrogen. This has led to a serious imbalance in nutrient use which must be corrected if the current momentum in improving crop yields is to be maintained. Following a decade of total stagnation during the Cultural Revolution, agricultural research and education facilities are being strengthened. Younger scientists, many with overseas training, are being placed in key positions. China is still a developing country, and much remains to be done; however, progress in the last decade, and especially in the past five years, has been remarkable.

• Journal of Korea Multimedia Society
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• v.21 no.10
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• pp.1182-1194
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• 2018

The Dynamic Adaptive Streaming over HTTP(DASH) is envisioned to evolve to meet an increasing demand on providing seamless video streaming services in the near future. The DASH performance heavily depends on the client's adaptive quality selection algorithm that is not included in the standard. The existing conventional algorithms are basically based on a procedural algorithm that is not easy to capture and reflect all variations of dynamic network and traffic conditions in a variety of network environments. To solve this problem, this paper proposes a novel quality selection mechanism based on the Deep Q-Network(DQN) model, the DQN-based DASH Adaptive Bitrate(ABR) mechanism. The proposed mechanism adopts a new reward calculation method based on five major performance metrics to reflect the current conditions of networks and devices in real time. In addition, the size of the consecutive video segment to be downloaded is also considered as a major learning metric to reflect a variety of video encodings. Experimental results show that the proposed mechanism quickly selects a suitable video quality even in high error rate environments, significantly reducing frequency of quality changes compared to the existing algorithm and simultaneously improving average video quality during video playback.

• Journal of Korean Academy of Nursing
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• v.14 no.2
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• pp.28-37
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• 1984

The purpose of this study is to propose the baseline data for developing the stress measurement tool for staff nurses working in the hospital. Two hundred and fifteen stan nurses in Seoul National University Hospital were participated during the period from Feb. 28 to Mar. 10, 1984. Though the pretest and literature review a questionnaire was constructed with 63 stressors which were experienced by the nurses in the hospital. Subjects were given instruction to rate 1∼6 likert type scale according to the level of stress experienced by each stressor described. Reliability of the tool was tested by Cronbach's Alpha, and the result was α=0.94871. Factor analysis was applied to organize 63 items together. As the result, 15 factors were obtained and these factors explained 66.3% of variance. The 15 factors were: 1) Work overload 2) Role conflict as a profession 3) Lack of professional knowledge and skill 4) Interpersonal problem 5) Conflict in nurse doctor relationship 6) Work conflict with doctors 7) Emotional burden due to the limitation of medicine 8) Poor treatment 9) Unsatisfactory relationship with supervisor 10) Low reward 11) Unsatisfactory relationship with subordinate 12) Poor physical environment of unit 13）Responsibility for extra affairs 14）Unfamiliar situation 15）Night duty.

• The Korean Journal of Community Living Science
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• v.14 no.1
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• pp.13-35
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• 2003

This study aims at analyzing the leadership-types that have been affecting the social capital of community organization. The methods for this study are literatures review and survey to community organizations in Daegucity and Kyungpook. The questionnaires are sent to 426 leaders who are community organization leaders, 35.%(150) of the total returned questionnaire. The statistical methods used for the data were frequency, percentile, and regression. The major findings of this study are summarized as follows: 1)Direction for improving the social capital of community organization aspect of respondent's personal characteristic (1)female members' rate of community organization should be more high. (2)leader's age is to be over fifty, and educational background of high school is resonable. (3)the leader's religious is buddhism, the leaders of community organization should take the adult education program that related to leadership. 2)Resonable leadership-types to improve the social capital of community organization as follow; (1)reformative leadership is more important than trading leadership for affecting positively the social capital of community organization. (2)the authoritative leadership of reformative leadership-types is the most important than anyone else. (3)the condition-reward leadership of trading leadership types is affecting positively the social capital of community organization. And the authoritative leadership is needed for increasing the social capital of community organizations in Daegucity and Kyungpook.

• Korean Journal of Occupational Health Nursing
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• v.23 no.4
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• pp.219-226
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• 2014

Purpose: This study aims to determine the association between psychosocial work environment and self-rated health among general hospital nurses. Methods: A total of 195 nurses working in one general hospital were eligible for data analysis by multivariate logistic regression. The psychosocial work environment was measured with the Korean version of the Copenhagen Psycosocial Questionnaire version II (COPSOQ-K). Self-rated health was recoded as good (excellent/good) and not good (fair/poor/bad) to the question, "In general, how would you rate your health status?" Results: 40% of nurses rated their health positively. Commitment to the workplace (OR=1.27), predictability (OR=1.32), recognition and reward (OR=1.41), role clarity (OR=1.32), and social support from colleagues (OR=1.25) were positively associated with self-rated health of nurse participants. Work-family conflict (OR=0.82) was negatively associated with self-rated health. Conclusion: The findings suggest that psychological work environment predicts self-rated health of hospital nurses. Good psychological work environment may be helpful in improvement of nurses' health.

• Research in Community and Public Health Nursing
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• v.18 no.3
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• pp.441-451
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• 2007

Purpose: The purpose of this study is to analyze the smoking behaviors and to identify the impacts of depression, temperament, and characteristic on smoking experience in the female adolescents. Methods: This study surveyed 691 highschool girls in the Gangwon area using self -administered questionnaires. Data were analyzed by SPSS 12.0. using Pearson correlation coefficient and multiple regression. Results: The smoking rate of the highschool girls was lower than that of the national average. Depression was observed to be seriously in the highschool girls. There were a positive correlations among smoking experience, the school records and novelty seeking and a negative correlation between smoking and cooperativeness. The significant predictors of smoking experience were the type of school, the satisfaction with school the school records, novelty seeking, reward dependence and cooperativeness. Conclusion: These results suggest that femalel adolescents who have the factors identified in this study are considered to have the potential for smoking. These results provide the basis for developing smoking prevention and cessation programs.

• Korean Medical Education Review
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• v.9 no.2
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• pp.13-20
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• 2007

Purpose : The aim of this study is to analyse the research productivity of SCI publications at medical schools in Korea. Methods: We collected the 5,386 SCI publications from 10 medical schools that were published in 2002 and 2003. Most of the materials treated herein are derived from the database of the Institute of Scientific Information from April 13, to May 25, 2005. Values are analyzed by medical school, major and IF index and presented as frequency and percentages. Results : There were 2,350 publications in 2002 and 3,036 publications in 2003. The average publication rate per faculty was .71 in 2002 and it was increased to .90 in 2003. Of the total 5,386 manuscripts, 1.248(23.2%) papers were from work conducted at basic science department and 3,224(76.8%) were from work performed at clinical science department. The major such as pathology, microbiology, pharmacology, internal medicine, diagnostic radiology and dermatology published a lot of SCI papers. A large percentage of papers (41.74%) were in journals with reported l<=IF<3. Conclusions : There was wide variability in the research productivity among the medical schools or majors. This variability reflects the importance of the institutional characteristics of each medical school in predicting the research productivity. Some of these institutional characteristics include the size of the faculty. available research funding, research vision of medical school, visible system of measurement and any associated reward system.

• Korean Journal of Construction Engineering and Management
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• v.24 no.5
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• pp.73-82
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• 2023

Optimization of Construction Site Layout Planning (CSLP) heavily relies on workers' travel paths. However, traditional path generation approaches predominantly focus on the shortest path, often neglecting critical variables such as individual wayfinding tendencies, the spatial arrangement of site objects, and potential hazards. These oversights can lead to compromised path simulations, resulting in less reliable site layout plans. While Deep Reinforcement Learning (DRL) has been proposed as a potential alternative to address these issues, it has shown limitations. Despite presenting more realistic travel paths by considering these variables, DRL often struggles with efficiency in complex environments, leading to extended learning times and potential failures. To overcome these challenges, this study introduces a refined model that enhances spatial navigation capabilities and learning performance by integrating workers' visibility into the reward functions. The proposed model demonstrated a 12.47% increase in the pathfinding success rate and notable improvements in the other two performance measures compared to the existing DRL framework. The adoption of this model could greatly enhance the reliability of the results, ultimately improving site operational efficiency and safety management such as by reducing site congestion and accidents. Future research could expand this study by simulating travel paths in dynamic, multi-agent environments that represent different stages of construction.

• Journal of Information Processing Systems
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• v.19 no.2
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• pp.240-257
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• 2023

The industrial Internet of Things (IIoT) is characterized by intelligent connection, real-time data processing, collaborative monitoring, and automatic information processing. The heterogeneous IIoT devices require a high data rate, high reliability, high coverage, and low delay, thus posing a significant challenge to information security. High-performance edge and cloud servers are a good backup solution for IIoT devices with limited capabilities. However, privacy leakage and network attack cases may occur in heterogeneous IIoT environments. Cloud-based multi-party computing is a reliable privacy-protecting technology that encourages multiparty participation in joint computing without privacy disclosure. However, the default cloud selection method does not meet the heterogeneous IIoT requirements. The server can be dishonest, significantly increasing the probability of multi-party computation failure or inefficiency. This paper proposes a blockchain and smart contract-based optimized cloud node selection framework. Different participants choose the best server that meets their performance demands, considering the communication delay. Smart contracts provide a progressive request mechanism to increase participation. The simulation results show that our framework improves overall multi-party computing efficiency by up to 44.73%.