• Journal of Communications and Networks
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• v.18 no.4
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• pp.610-618
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• 2016

A green cognitive radio network (CRN), characterized by base stations (BSs) that conserve energy during sleep periods, is a promising candidate for realizing more efficient spectrum allocation. To improve the spectrum efficiency and achieve greener communication in wireless applications, we consider CRNs with an long term evolution advanced (LTE-A) structure and propose a novel energy-saving strategy. By establishing a type of preemptive priority queueing model with a single vacation, we capture the stochastic behavior of the proposed strategy. Using the method of matrix geometric solutions, we derive the performance measures in terms of the average latency of secondary user (SU) packets and the energy-saving degree of BSs. Furthermore, we provide numerical results to demonstrate the influence of the sleeping parameter on the system performance. Finally, we compare the Nash equilibrium behavior and social optimization behavior of the proposed strategy to present a pricing policy for SU packets.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.3
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• pp.51-63
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• 1993

We consider a cyclid server system under N-policy. This system consists of multiple queues served in a cyclic order by a single server. In this paper, we consider the following control policy. Every time server polls one queue, the server inspects the state of the queue. If the total number of units is found to have reached or exceeded a pre-specified value, the server begins to serve the queue until it is empty. As soon as the queue becomes empty, the server polls next queue. An approximate analysis of this system is presented. Sever vacation model is used as an analytical tool. However, server vacation periods are considered to be dependent on the service times of respective queues. The results obtained from the approximate analysis are ompared with simulation results.

• Journal of applied mathematics & informatics
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• v.6 no.1
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• pp.309-320
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• 1999

Models of single-server queues with vacations have been widely used to study the performance of many computer communi-cation and production systems. In this paper we analyze an M/G/1 queue with generalized vacations and exhaustive service. This sys-tem has been shown to possess a stochastic decomposition property. That is the customer waiting time in this system is distributed as the sum of the waiting time in a regular M/G/1 queue with no va-cations and the additional delay due to vacations. Herein a general formula for the additional delay is derived for a wide class of vacation policies. The formula is also extended to cases with multiple types of vacations. Using these new formulas existing results for certain vacation models are easily re-derived and unified.

• Journal of Family Resource Management and Policy Review
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• v.23 no.2
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• pp.17-40
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• 2019

The purpose of this study is to analyze the present condition of work-leisure balance and its influencing factors in employed young single households. Three groups of sample households-work-oriented, balanced, and leisure-oriented-were compared by factors related to work and leisure. Six cases were interviewed to obtain qualitative data on the subjective meaning of work-life balance and its influencing factors. The results showed different characteristics between the three groups based on the various work- and -leisure- related factors: average weekly working hours of the week, number of vacation days per year, weekday leisure time, degree of weekday freedom, and sufficiency of the leisure cost. In addition, the characteristics considered desirable for quality of life differed between groups. Finding the meaning of life through work and leisure was very important for those respondents, who have an unstable position in the labor market, and who want to delay making decisions on moving into the marriage and family-building phase recognized as a major development task for Korean adults.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.2
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• pp.29-39
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• 2018

In this paper, we discuss a discrete-time queueing system with dyadic server control policy that combines workload control and multiple vacations. Customers arrive at the system with Bernoulli arrival process. If there is no customer to serve in the system, an idle single server spends a vacation of discrete random variable V and returns. The server repeats the vacation until the total service time of waiting customers exceeds the predetermined workload threshold D. In this paper, we derived the steady-state workload distribution of a discrete-time queueing system which is operating under a more realistic and flexible server control policy. Mean workload is also derived as a performance measure. The results are basis for the analysis of system performance measures such as queue lengths, waiting time, and sojourn time.

• Journal of the Korean Institute of Educational Facilities
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• v.18 no.4
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• pp.33-43
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• 2011

The purpose of this study is to clearify the architectural pattern of the Dogsedang(讀書堂) and it's characteristics of the Place which based on the historical background of the Saga-reagingsystem(陽假讀書制度) in the early Chosun Dynasty. The Saga-reaging(賜暇讀書) was given vacation to read books for young scholars who serve in a Royal institution chartered an academic society that we call the Giphyunjeun(集賢默). Due to the consciousness of preference about the old Documment on the history of Chosun Dynasty such as, whangchoshillok(朝蘇王朝實錄) and giligie(地理誌) and so on, I could find a clue that would lead to the solution of the problem. So to speak the division into periods about historical background of the Saga-reagingsystem(賜暇讀書制度) is analysed by questionnaire of scholars who is in. By the analysis, there were two types of the Saga-reagingsystem(賜暇讀書制度) and three places in the Dogsedang(讀書堂). Vacation to read books at the single schalor's home is we called jaegadogse(在家讀書), reading area at the temple in the deep mountain district is the Sansadogse(山寺讀書). The first place reading area at the temple in the deep mountain district was the temple of Jinkwan(律寬寺), the second place was the temple of Jangyue(藏義寺) the third was the temple of youngsan(龍山寺) so called the Namhodang(南湖堂). There is a certain difference of viewpoint with each site. These results show that the site of the Dogsedang(讀書堂) has deep consideration in relation with picturesque scenery.

• The Journal of the Korea Contents Association
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• v.20 no.12
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• pp.332-345
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• 2020

This study sought to explore the demand in the social service sector and present policy implications, focusing on the vulnerable in rural villages exposed to worse conditions amid the Covid-19 crisis. To this end, the social service needs of vulnerable groups by household type were analyzed by utilizing the raw data of the 2018 Survey on Rural Well-Being. Analysis showed that the greatest demand social services for all rural villages, the elderly, the disabled, one-person, one elderly and low-income households were income support services, while in household that included children the demand was for childcare and education-related services. The second-highest social services in terms of demand were cultural leisure vacation support services for all rural villages, healthcare-related services for the elderly, the disabled, one elderly and low-income households, cultural leisure vacation support services for households including children and daily life support services for single-person households. Based on these results, a measure was proposed to support social services, tailored to vulnerable groups in rural villages. In addition, the government's lack of a consultation system between urban and rural welfare policies, such as a basic plan for health and welfare in rural villages, led this paper to discuss the need for a feedback function and dedicated formulation of mid- to long-term policies in rural villages. It also proposed the establishment of conditions for providing customized social services for rural villages.

• The Journal of the Korean Institute of Forest Recreation
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• v.22 no.4
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• pp.23-33
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• 2018

The purpose of this research is to develop basic materials useful for the visiting management policies' establishment of national parks by analyzing the characteristics of and satisfaction with the visit to Hallyeohaesang National Park according to travel routes. For this, a total of 671 visitors to Hallyeohaesang National Park were recruited and field surveys were conducted three times in spring, summer, and fall from March to November 2017. The Hallyeohaesang national park's visitors were surveyed using a self-administered questionnaire about visitor characteristics (ex: motivation of visiting, travel routes, travel time, and participating activities, etc.) and satisfaction (ex: satisfaction with the visit, intention to revisit, and intention to recommend). SPSS 21.0 program was used for the statistical analysis: frequency analysis and independent-samples t-test analysis. As a result of analysis the motivation of visiting, those who visited only Hallyeohaesang National Park (a single destination) showed a mean value statistically significantly higher level in health improvement and vacation, relaxation, and healing compared to those who had visited or would visit other places along with Hallyeohaesang National Park (multi-destinations). Single destination visitors spent less time traveling from home to national park than multi-destinations visitors. Those who visited only Hallyeohaesang National Park (as a single destination) showed a mean value statistically higher satisfaction and intention to revisit and recommend. The results of this research have significance in providing basic materials to develop efficient park management policies by studying the characteristics of Hallyeohaesang National Park visitors.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.2
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• pp.69-80
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• 2024

In this paper, we studied a discrete-time queuing system that operates under a mixed situation of D-policy and T-policy, one of the representative server control policies in queuing theory. A single server serves customers arriving by Bernoulli arrival process on a first-in, first-out basis(FIFO). If there are no customers to serve in the system, the server goes on vacation and returns, until the total service time (i.e., total amount of workload) of waiting customers exceeds predetermined workload threshold D. The operation of the system covered in this study can be used to model the efficient resource utilization of mobile devices using secondary batteries. In addition, it is significant in that the steady state waiting time and system sojourn time of the queuing system under a flexible mixed control policy were derived within a unified framework.