• 한국멀티미디어학회논문지
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• 제18권5호
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• pp.620-630
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• 2015

This research suggests a load balancing method for a volume rendering system which supports concurrent users. When concurrent users use a volume rendering server system, the computational resources are occupied by a particular user by turns because each process consumes the computational resources as much as possible. In this case, the previous method shows acceptable throughput but the latency is increased for each user. In this research, we suggest a method to improve the latency without performance degradation. Each process makes concessions for taking the resources according to the number of users connected to the system. And we propose a load balancing method in the dynamic situation in which the number of users can vary. Using our methods, we can improve the latency time for each user.

• Journal of Information Technology Applications and Management
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• 제27권6호
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• pp.197-224
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• 2020

Mobile games have become one of the most important driving forces of the game industry. We focus on the continuous intention to use Chinese mobile games from the perspective of experiential marketing and network externalities. We integrate user experience, network externalities and flow theory into expectation confirmation model and explore the influencing factors of continuous usage intention of Chinese mobile game and propose a research model. Game experience, service experience, perceived enjoyment, social interaction, challenge, perceived number of users and perceived number of peers were employed as independent variables, while flow, perceived value and satisfaction as mediating variables and continuous intention as the dependent variable. After surveying 426 samples, the model is tested with structural equation model. The results reveal that perceived enjoyment significantly positively influences perceived value, flow, satisfaction, and continuous intention. The greater the enjoyment of the game, the greater the satisfaction of the game and the greater the willingness to use it continuously. Game experience has a significant direct effect on continuous intention, which indicates that a better game experience can retain more users. Service experience and perceive number of peers positively influence satisfaction. Another finding is that social interaction and perceived number of users positively influence perceived value and flow, which indicate that social attributes are critical roles for retaining users. Game challenge also positively influences flow. The proper level of challenge is more likely to cause users to enter the state of flow. Flow indirectly influences continuous usage intention through the satisfaction of the game, which indicates that satisfaction is driven by flow experience and further retaining users. Empirical results implied that mobile game companies need to focus on improving user experience, expectation satisfaction and extending network externalities to improve the continuous intention of using mobile game.

• Journal of Computing Science and Engineering
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• 제4권2호
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• pp.173-187
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• 2010

Recent technological advances in mobile communication systems have made explosive growth in the number of mobile device users worldwide. One of the most important issues in designing a mobile computing system is location management of users. The hierarchical systems had been proposed to solve the scalability problem in location management. The scalability problem occurs when there are too many users for a mobile system to handle, as the system is likely to react slow or even get down due to late updates of the location databases. In this paper, we propose a top-down clustering algorithm for hierarchical location database systems in a wireless network. A hierarchical location database system employs a tree structure. The proposed algorithm uses a top-down approach and utilizes the number of visits to each cell made by the users along with the movement information between a pair of adjacent cells. We then present a modified algorithm by incorporating the exhaustive method when there remain a few levels of the tree to be processed. We also propose a capacity constraint top-down clustering algorithm for more realistic environments where a database has a capacity limit. By the capacity of a database we mean the maximum number of mobile device users in the cells that can be handled by the database. This algorithm reduces a number of databases used for the system and improves the update performance. The experimental results show that the proposed, top-down, modified top-down, and capacity constraint top-down clustering algorithms reduce the update cost by 17.0%, 18.0%, 24.1%, the update time by about 43.0%, 39.0%, 42.3%, respectively. The capacity constraint algorithm reduces the average number of databases used for the system by 23.9% over other algorithms.

• 한국컴퓨터정보학회논문지
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• 제10권4호
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• pp.259-274
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• 2005

본 논문은 전자상거래 시스템의 수용 가능한 사용자 수를 예측하는 방법론을 제안한다. 폐쇄된 LAN상의 시스템에서 수용 가능한 사용자 수에 대해서는 이전문헌에 다양한 연구가 있었으나 실제 인터넷 망을 대상으로 전자상거래 시스템의 사용자 수 예측에 관한 연구는 미흡한 실정이다. 본 연구에서는 종단간 초고속 인터넷 서비스 품질 측정 결과를 토대로 Hybrid Simulation에 적용하여 LAN과 WAN, 네트워크장비, 통신 대역폭 등에 대한 다양한 실험을 수행하였다. 구축한 전자상거래 시스템을 대상으로 한 실험결과, 초고속 인터넷 서비스 매체의 응답 시간은 연속적인 트랜잭션 깊이와 비 트랜잭션 대 트랜잭션 비율에 따라 달라진다는 사실을 관찰하였다. 즉, 망과 애플리케이션이 많은 일을 수행하고 있다면 수용 가능한 사용자 수는 감소되며, 반대의 경우는 수용 가능한 사용자 수가 증가하는 것을 실험을 통해 검증하였다. 또한 Cache Server, L4 Switch 등을 실험 모형에 추가한 실험을 통하여 수용 가능한 사용자 수 증가와 클라이언트 응답 시간의 감소 정도를 파악하였다.

• 대한인간공학회지
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• 제19권3호
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• pp.77-92
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• 2000

This study is about the satisfaction and the usage of users' manual for mobile phones with multi-functions. The users' manual is redesigned by including ergonomic factors verified through survey. This paper is to propose a redesigned users' manual which is more readable and understandable than original users' manuals. The degree of improvement is measured by the usability evaluation. There are significant differences(p<0.05) in the number of functional description original users' manuals. And the degree of users' satisfaction with the description of Crystal Display) are significant diffenences among the original users' manuals. In the as of description, the significant differences are partially found. The users' manual is re arranging the explanations of functions compactly in a table form, and reducing the cl has also $3cm^*2cm$ LCD figures to facilitate the understanding. The usability evaluation users' satisfaction and understanding for the redesigned users' manual are higher than original users' manuals.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.25-28
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• 2000

In this paper, we assume various number of multipaths in one chip duration according to spreading bandwidth. And we take into account of the effects of autocorrelation and relative phases among multipath components within one chip duration, and analyze fading effects. We derive the average error probability for different number of users. Then, we compare the performance of W-CDMA systems with different bandwidths. From the simulation results for different band-widths, wideband CDMA systems show better performance than narrowband CDMA systems in vehicular and pedestrian environments.

• 대한인간공학회지
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• 제29권5호
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• pp.771-782
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• 2010

Today, the number of elderly drivers who use navigation is increasing with the growing number of elderly drivers. The purpose of this study is to provide guidelines on the interface of car navigation for elderly users. To extract significant factors which were distinguished between young and elderly users, both young and elderly users executed the driving test by installing two car navigation alternatives. The analysis was conducted through t-test. The results show that significantly different factors were the number and the meaning of the menu items in the initial screen, the location and the meaning of the menu icons in the map screen, the ease of search of the menu and the text size in the menu screen. Improvements for the factors of the initial screen and map screen were made with reference to ergonomic guidelines, and suggested through experiments comparing design alternatives for the menu screen. Design alternatives were made through a combination of investigative variables, and the analysis was conducted through ANOVA. The results show that Alternative 7 (the location of the tab was placed at the bottom, menu representation was done with the text font size of 18pt and the location of menu navigation icons was shown at the upper left) was preferred in terms of user's preference and the execution time. So if the suggested menu for elderly users are added to the existing design, both users will satisfy their desires. The guidelines suggested in this study will help the designer of car navigation take elderly users into consideration.

• 한국환경생태학회지
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• 제32권2호
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• pp.231-243
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• 2018

본 연구는 방문객 유형별로 장성 편백치유의 숲(Jangseong Pyunbaek Healing Forest: JPHF) 내 '치유필드'의 이용객수에 대한 지각(perceived number of users: PNU)과 이용객수에 대한 평가기준(evaluative standards)을 설정, 비교하기 위해 시행되었다. 2017년 9월 중 JPHF 내 '치유필드' 이용객을 대상으로 편의표본추출 방법을 통해 선정된 158명의 표본으로부터 설문지기법을 이용하여 자료를 수집하였다. 치유필드 방문객 중 휴양객(일반 휴양을 목적으로 한 방문객)은 49.3%, 치유객(건강 및 치유를 목적으로 한 방문객) 15.3%, 휴치객(휴양과 치유를 동일정도로 추구하는 방문객) 35.3%로 구성되어 있었다. 응답자가 지각하는 치유필드 이용객수는 전체적으로는 평균 23.8명(중앙값: 20.0명)으로 나타났으며, 방문객 유형별 평균범위는 21.1-27.8명(중앙값: 20.0명 동일)으로 조사되었다. 응답자의 PNU는 혼잡지각(perceived crowding: PC)(r=0.23) 및 치유경험 방해 지각(perceived interference of healing experience: PIHE) (r=0.20)과 낮은 상관관계를 나타냈다. 방문객 유형 간에 치유필드 적정이용객수(optimal number of users: ONU)는 차이가 없었다. 전체적으로 적정이용객수는 평균 28.9명(중앙값: 25.0명)으로 나타났으며 방문객 유형별 적정이용객수 범위는 평균 25.4-31.4명(중앙값: 25.0-27.5명)으로 분석되었다. 또한 최대 허용가능 이용객수(maximum acceptable number of users: MANU)는 전체적으로 38.1명으로 나타났으며, 방문객 유형별로는 휴양객 36.9명, 치유객 32.0명, 휴치객 38.0명으로 각각 조사되었다. 방문객 유형별로는 MANU에 차이가 없었다. 응답자의 PC는 평균 2.73(SD: 3.26, 9점 척도), PIHE는 평균 3.26(SD: 1.77, 9점 척도)으로 나타났으며 방문객 유형별로는 휴치객이 휴양객에 비해 통계적으로 높은 PC와 PIHE를 보였다. PNU가 ONU를 초과한 그룹은 그렇지 않은 그룹에 비해 높은 PC와 PIHE를 나타냈다. 연구결과를 토대로 관리적 관점에서의 시사점을 제시하였으며 본 연구의 한계점과 추후 연구에 대하여 토의하였다.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.183-189
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• 2013

In this paper, we propose a capacity modeling method for Bluetooth based LBSs (Location Based Services) between Bluetooth APs(Access Points) and mobile phones. In order to do this, we consider the entrance and exit of the users to and from the AP. Using parameters such as the connection time, data transmission time and number of users in the AP zone, we analyze the capacity of a Bluetooth AP using an appropriate queuing model. The required number of APs in a certain zone is estimated from the number of users in the zone using the proposed queuing model. By performing simulations and experiments, the validity and applicability of the proposed method are verified.

• 대한인간공학회지
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• 제36권3호
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• pp.197-211
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• 2017

Objective: We propose to apply color information to facilitate finding books in the library. Background: Currently, books are classified in the basis of a decimal classification system and a call number in the library. Users find a book using the call number. However, this classification system causes various difficulties. Method: In a process analysis and survey study, we identify what the real problem is and where the problem is occurred. To solve the real problems, we derived a new search method using color information. We conducted a comparative experiment with 48 participants to see whether the new method can show higher performance. Results: The new method using color information showed faster time and higher subjective rating scores than current call number method. Also, the new method showed faster time regardless of the skill level while the call number method showed time differences in terms of the skill level. Conclusion: The effectiveness of the proposed method was verified by experiments. Users will be able to find the desired book without difficulty. This method can improve the quality of service and satisfaction of library use. Application: Our book search method can be applied as a book search tool in a real public library. We hope that the method can provide higher satisfaction to users.