• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.890-900
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• 1999

In homogeneous multiprocessor systems, the task allocation algorithm which equally assigns tasks to processors if possible is generally used. But this algorithm is not suitable to accomplish to accomplish effective task allocation in heterogeneous multiprocessor systems. JSQ (Join the Shortest Queue) algorithm is often used in heterogeneous multiprocessor systems. Unfortunately, JSQ algorithm is not efficient when the differences of capabilities of processors are far large. To solve this problem, we suggest a heuristic task allocation algorithm that makes use of dynamic information such as task arrival time, task service time, and number of finished tasks. The results of simulation show that the proposed heuristic allocation algorithm improves the system performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.115-120
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• 2010

Products companies, which manufactures finished goods with modular parts, will expect that the proper parts should be delivered to assembly line not only just in time (JIT) but also just in sequence (JIS) and also expect that faulty goods will not be produced due to the delivery of wrong parts. In order to satisfy the above requirements, recently Smart Pallet based Parts Delivery system (SPPD) was proposed. SPPD system can overcome the drawback of bar code based part delivery system in which much time for checking proper and in sequence parts is wasted due to labors' working in hand as well as the drawback of RFID based part delivery system in which recognition distance of RFID is very limited. In the paper, a PDA system is proposed and further implemented to maximize the efficiency of SPPD's operation as well as to manage the limited power of smart pallets efficiently.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.06a
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• pp.171-183
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• 2000

Regarding the ancient Sino-Kroea sea communication as the main theme, the propagation of the China-culture in Koran Peninsula and he influence of Chinese ancient shipbuilding technique for Korea are described in the paper. Frequent sea trade resulted in the flourishing of Chinese and Korean harbours on both side of Yellow Sea. Sino-Koran sea communication is of long-standing. Korean Peninsula (KP) is just as the large arm extended to the great sea from the North-east China. It is the Chinese mainland plate-lump's extended part in the Yellow Sea. In the ancient time, the land communication between China and Korea was often not unimpeded, the contact between China and KP, such as the South-Korea, depended on the sea communication mainly, Although the friendly relationship between China and Korea rose one after another in the various historical period, but considering from the great background of people's historical development, just as the modern people benefited fro the Europe-American culture, the people of ancient time also benefited from the China-culture. All China, KP and Japan obtained the development by propagating the ancient China-culture. The seagoing ships which carried out the Sino-Korea sea communication and trade, as the friendly envoys, finished the mission linked u and developed the Sino-Korea culture contact.

• Steel and Composite Structures
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• v.21 no.3
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• pp.501-515
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• 2016

Seismic analysis for steel frame structure with brace configuration using topology optimization based on truss-like material model is studied. The initial design domain for topology optimization is determined according to original steel frame structure and filled with truss-like members. Hence the initial truss-like continuum is established. The densities and orientation of truss-like members at any point are taken as design variables in finite element analysis. The topology optimization problem of least-weight truss-like continuum with stress constraints is solved. The orientations and densities of members in truss-like continuum are optimized and updated by fully-stressed criterion in every iteration. The optimized truss-like continuum is founded after finite element analysis is finished. The optimal bracing system is established based on optimized truss-like continuum without numerical instability. Seismic performance for steel frame structures is derived using dynamic time-history analysis. A numerical example shows the advantage for frame structures with brace configuration using topology optimization in seismic performance.

• Journal of Haehwa Medicine
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• v.11 no.1
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• pp.237-256
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• 2002

In view of the results that we studied about living and eating habit of korean old people who live in longevity village, we can make conclusion as follows. 1. They have regular rising time, bedtime and living routine. Their bedtime is between 9 to 11 and rising time is before 6. It goes to show that they are keeping regular hours. 2. Generally speaking, most of long life peoples are physical labor: agriculture, fishery, housework, etc. 3. They are in balance with their eating habit. The most favorite food of longevity village's old people is made from toenjang which is fermented soybean paste. 4. The geographical features of longevity village are mountain region, coast and island. 5. Most of people who live long are illiteracy and only a few people of them has finished elementary school course. Moreover, in case of illiteracy, there are more unschooled woman compare with both sexes.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.6
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• pp.714-719
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• 2011

The surface roughness depending on the machining method is very important because is produce a finished product through riveting, sealing, bonding, and special paint in order to curb the turbulence and air resistance which occur between the sheets. Aluminum alloy 2024 which is widely used for interior and exterior material of aircraft are tested. Jin-young JW-60C wire cutting machine was used in this experiment. In this paper, the experimental investigation has been performed to find out the influence of the surface roughness and surface shape characteristics on the wire-cut EDM of discharge energy in aluminium alloy 2024. The selected experimental parameters are peak current, no-load voltage, off time and feed rate. The experimental results give the guideline for selecting reasonable machining parameters. The high discharge energy on the idle time, almost no change in surface roughness can be seen.

• Korean Institute of Interior Design Journal
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• v.17 no.5
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• pp.107-114
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• 2008

With the exhibition materials and exhibition spaces are provided, it is the reaction of the visitors that completes the function of science museum. To satisfy the visitors, it is necessary to understand their needs, interests, and motives, apart from the physical environment of the museum. The purpose of this research is to verify the effect of children's personal characteristics on the satisfaction in science museum. In doing so, an interview survey was conducted: 210 primary and middle school students who had finished the exhibition tour were randomly selected and interviewed. The data was analysed by a T-test and an one-way ANOVA to find out the correlation. The results of analysis are as follows: First, a meaningful statistical differences are found by the age groups in terms of motivation, expectation, satisfaction, enjoyment, and total staying time at the museum. The lower the grade, students are satisfied with their everyday living; and this is reflected on their intrinsic motivations and higher expectations on visit. Also, their actual satisfaction and enjoyment are higher and they stay at the museum longer than the other group. Second, the group with intrinsic motivation and higher expectation is more satisfied with the contents of the exhibition than the group with extrinsic motivation. Third, the level of higher education of mothers, rather than that of fathers had mere effect on the learning of the children at the museum. Also, the children who are brought up by full-time house wives have bigger achievement of learning from the exhibition than those with working mothers.

• Journal of Biosystems Engineering
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• v.28 no.6
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• pp.497-504
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• 2003

The objectives of this study were to develop a harvesting gripper for perilla leaves and test its performance, which was a partial work of the automated perilla leaves harvesting system development. The results of this study could be summarized as the followings: The shear forces for harvesting the perilla were measured. The measured results showed that the average shear force required was 12.13N for cutting the petioles attached to the perilla stalks, and the maximum of 17.42N. The inner diameter of air cylinder used was 6mm and the air pressure was maintained as 0.7㎫ during the tests. The time required for cutting perilla leaves could be adjusted by the control program and cutting operation could be done within 1- 10 seconds. The performance tests were conducted to harvest the perilla leaves by the gripper developed. The average success rates of cutting were 72.2％ for the first test, 78.5％ for the second, and 74.2％ for the last. The perilla leaves were not damaged by the gripper The whole system operation could be finished within three seconds except the delay time for dropping harvested leaves.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1608-1610
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• 1998

An oil-filled paper-insulated power cable and a XLPE-insulated power cable have been mainly applied as an extra-high-voltage underground power cable. But in recent the XLPE cable has been applied more widely than the OF cable, because of its advantages, such as the low-cost and simple installation. In general two types, molded and prefabricated, of straight joints are applied for the XLPE cables. For a tape-molded joint, one of molded joints, its electrical properties are excellent, but it has some disadvantages, such as a long working time. high skill of workers and the high cost of jointing equipments. For a prefabricated joint, developed and applied in Europe and Japan, its working time is short, its jointing procedures are simple, and its quality control is easy, but its prices are very high. In Korea the development of a compression-type PJ will be finished in the near future, and studies of its jointing techniques and equipments is actively going on. This paper describes the design and construction of the PJ, the jointing procedures and techniques for the PJ, and its future trends.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.3
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• pp.89-93
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• 2007

In this study, we consider an assembly line operated under a base-stock policy. A product consists of two parts, and a finished product transfers to a warehouse in which demands are satisfied. Assume that demands arrive according to a Poisson process and processing times at each production line are exponentially distributed. Whenever a demand arrives, it is satisfied immediately from an inventory in the warehouse if available; otherwise, it is backlogged and satisfied later by the next product exiting from production lines. In either case, an arriving demand automatically triggers the production of a part at both production lines. These two parts will be assembled into a product that eventually transfers to the warehouse. We obtain a closed form formula of approximation for delay time or lead time distribution of a demand when a base- stock level is s. Moreover, it can be applied to the optimal base-stock level which minimizes the total inventory cost. Numerical examples are presented to show our optimal base-stock level's quality.