• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.2
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• pp.57-71
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• 2023

In this study, we analyze a finite-buffer M/G/1 queueing model with randomized pushout space priority and nonpreemptive time priority. Space and time priority queueing models have been extensively studied to analyze the performance of communication systems serving different types of traffic simultaneously: one type is sensitive to packet delay, and the other is sensitive to packet loss. However, these models have limitations. Some models assume that packet transmission times follow exponential distributions, which is not always realistic. Other models use general distributions for packet transmission times, but their space priority rules are too rigid, making it difficult to fine-tune service performance for different types of traffic. Our proposed model addresses these limitations and is more suitable for analyzing communication systems that handle different types of traffic with general packet length distributions. For the proposed queueing model, we first derive the distribution of the number of packets in the system when the transmission of each packet is completed, and we then obtain packet loss probabilities and the expected number of packets for each type of traffic. We also present a numerical example to explore the effect of a system parameter, the pushout probability, on system performance for different packet transmission time distributions.

• The KIPS Transactions:PartC
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• v.12C no.5 s.101
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• pp.687-694
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• 2005

In ATM and W networks, high Priority Packets should be selectively favored over low Priority Packets in case of congestion. For this purpose, we introduce a space priority policy for ATM nodes in this paper which is very similar to the weighted core-stateless fair queueing(WCSFQ) in IP nodes. We also analyze the loss probabilities for different classes of cells for MMPP/D/1/K with a threshold level, and discuss the numerical results. The numerical results illustrate that the WCSFQ scheme can be used to support the differentiated services in ATM or IP nodes.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.141-144
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• 1991

In this paper, we analyze the performance of ATM switch with output buffer which has a space priority control mechanism. As we assumed that the input traffic consists of loss tolerable voice and loss sensitive data, we modeled it with MMPP(Markov Modulated Poisson Process). We confirmed that the loss probability of loss sensitive traffic decreases when we use the space priority control mechanism.

• Industrial Engineering and Management Systems
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• v.12 no.3
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• pp.274-280
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• 2013

This paper proposes a space merging approach to studying the queuing models with finite buffers and jump priorities. Upon the arrival of a call with low priority, one call of such kind is assumed to be transferred to the end of the queue of high priority calls. The transfer probabilities depend on the state of the queue of the heterogeneous calls. We developed the algorithms to calculate the quality of service metrics of such queuing models, and the results of the numerical experiments are shown.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.107-115
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• 1998

A path planning using potential field method is very useful for the real-time navigation of mobile robots. However, the method needs high modeling cost to calculate the potential field because of complex preprocessing, and mobile robots may get stuck into local minima. In this paper, An efficient path planning algorithm for multiple mobile robots, based on the potential field method, was proposed. In the algorithm. the concepts of subgoals and obstacle priority were introduced. The subgoals can be used to escape local minima, or to design and change the paths of mobile robots in the work space. In obstacle priority, all the objects (obstacles and mobile robots) in the work space have their own priorities, and the object having lower priority should avoid the objects having higher priority than it has. In this paper, first, potential based path planning method was introduced, next an efficient collision-avoidance algorithm for multiple mobile robots, moving in the obstacle environment, was proposed by using subgoals and obstacle priority. Finally, the developed algorithm was demonstrated graphically to show the usefulness of the algorithm.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.5
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• pp.155-164
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• 2020

This research used Analytic Hierarchy Process(AHP) to analyze the importance and priority of functional space and evaluation factors of each functional space of the military dining facility. Dining in the military is an important factor in restoring combat power and promoting morale. The military dining facility serves as a not only for meals, but also for watching TV, education and club activities. Workers working in dining facility spend most of their work hours in dining facility, perform tasks such as cooking, dishwashing, and leftover disposal, and take breaks. As such, the military dining facility is a space where various functions are performed, and space planning should take into account these various functions when planning the building of the dining facility. However, the criteria for defense and military facilities, which are the basis for planning the space of military dining facility, are calculated only by simply analyzing the standard floor plan to match the size of the person-to. Therefore, when there is space to be reduced in the total area, there are side effects such as leaving visible table space without consideration for priority or functional space, unseen office space, and adjusting the entire area through reduction of the lounge. Accordingly, based on the priority of the space that the staff of the military dining facility considers important, this research aims to analyze the characteristics of each functional space through classification according to its unique function. This can be an indicator that can be used as a basis for future revision of the building floor area standards of the defense and military facilities standards, and it can improve usability with an efficient space plan that takes into account the characteristics of the Korean military and the satisfaction of its workers. Furthermore, efficient use of the defense budget through rational building plans can contribute to budget reduction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.6
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• pp.779-792
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• 1993

In a switching node or an ATM multiplexer of the ATM network, a good bandwidth utilization can be achieved by the priority control using the 1-bit(Cell Loss priority) in ATM cell header. In this paper, the mixed mechanism is proposed to make up for shortcomings of existing space priority control mechanisms and to decrease the loss probability of high priority cell and its performance is analyzed about the cell loss probability. To estimate the performance of proposed mixed mechanism, its cell loss probability is compared with those of non-priority mechanism, push-out mechanism and partial buffer sharing mechanism. The cell loss probability is analyzed using a M/D/1/N modeling and a 2-state MMPP/D/1/N modeling and also comparison between two modelings is made. To verify this result of numerical analysis, the computer simulation is performed for each mechanism using the simulation language, SIMSRIPT II.5.

• Korean Institute of Interior Design Journal
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• v.20 no.5
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• pp.34-41
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• 2011

Today, residential building is considered of be one of the most important space of their quality of life and health. Residential buildings should provide comfortable environments to support the activities of their occupants. And good residential buildings are made by appropriately combining residential spaces, such as living room, master bedroom, bedroom, kitchen, restroom, and so on. These combinations in residential building are must be compatible with the activities of the occupants and their needs. The objective of this research is to investigate and analyze the relative importance and space priority between residential space in residential buildings depending on occupants' characteristics, such as, gender and age. Especially, this research is to find space weighting factors for integrative evaluation in residential buildings based on occupant survey. These weighting factors play an important role in determining the relative importance of various residential spaces for integrative residential space evaluation. And, the result from this research will help designers and researchers to find space planning strategies in residential building, and develop new integrative evaluation framework for improving residential quality from the occupants' point of view.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.387-392
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• 1998

To establish a monthly data collection planning for the Ocean Scanning Multispectral Imager (OSMI), we have examined the global patterns of three impacting factors: pigment concentration, cloud cover, and sun glint. Other than satellite mission constraints (e.g., duty cycle), these three factors are considered critical for the OSMI data collection. The Nimbus-7 Coastal Zone Color Scanner (CZCS) monthly mean products and the International Satellite Cloud Climatology Project (ISCCP) monthly mean products (C2) were used for the analysis of pigment concentration and cloud cover distributions, respectively. And the monthly simulated patterns of sun glint were produced by performing the OSMI orbit prediction and the calculation of sun glint radiances at the top-of-atmosphere (TOA). Using monthly statistics (mean and/or standard deviation) of each factor in the above for a given 10$^{\circ}$ latitude by 10$^{\circ}$ longitude grid, we generated the priority map for each month. The priority maps of three factors for each month were subsequently superimposed to visualize the impact of three factors in all. The initial results illustrated that a large part of oceans in the summer hemisphere was classified into the low priority regions because of seasonal changes of clouds and sun illumination. Sensitivity tests were performed to see how cloud cover and sun glint affect the priority determined by pigment concentration distributions, and consequently to minimize their seasonal effects upon the data collection planning.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.85-88
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• 2002

Architectural space consists of the interior and the exterior. The layout and form of architectural space has a great variety of characters by region and culture. In other words, it can be understood which has a priority between the interior and the exterior in developing the layout and the form of architectural space. Belonging to the culture area of Chinese characters with Korea, Japan has maintained its own identity. It has an identity in the layout and form of architectural space as well. Therefore, the architecture and architectural theories of the two countries were compared and analyzed with priority given to the traditional architecture extending to the contemporary architecture, also the backgrounds of architecture and architectural theories of two countries were examined in this study. This study shows that each country has different characters in how to introduce nature, how to expand space and how to compose windows, including the view of nature and the cult of space. As a result, the space in Korean architecture has relatively the exterior-oriented character but in Japan architecture spatial character is interior-oriented. The interior-oriented character can be relevant to the word ‘reduction’ and the exterior-oriented character to ‘extension’ after all. Also it can be thought that each character has a great relation with climate and idea of people in power