• Journal of Korean Society of Industrial and Systems Engineering
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• v.1 no.1
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• pp.37-44
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• 1978

The purpose of this study is to search for an efficient application method in solving delay-phenomenon problems which influence upon total production cost through case study. The method of this study is an experimental study based on cutting time data in lead cutting operations from "Lead Cutting Machine (Stripper)" and its service rate data from a large electronic products company which utilizes conveyor line system for the products "Car Stereo" The procedure of this experimental study is as follows; 1) Using loading(Man-Hour) analysis technique j,1 order to analyse and evaluate Production capacity, efficiency, operation and idle rate assembly charge, waiting and service cost -when its are controlled by stripper operator(server) 2) Establishing adequate waiting time model of finite population caused by the interference of 4 stripper machine which is drawn from mathematical statistics testing, that is, goodness of fit test in the waiting and service rate and to search for optimal solution by utilizing the above mentioned model The experimental result was that amount to 8,546,618won Per year was brought down, that is, by optimum point, it shows a decrease as compared with Present point. The major limitation of this experimental study is that the Queue in the Finite Population, so to speak. it comes from the interference of 4 stripper machine dealt with this case were limited only on the Car Stereo conveyor line. Further study of application of this application method to the areas such as material handling, personnel management marketing and transportation management is strong1y recommended.trong1y recommended.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.28-28
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• 2008

Generally speaking, Rogowskii coil for magnetic flux change detection according to electric current is used for digital addition watt-hour meter, because it is not saturated at electromagnetic that not Current Transformer working by magnetic material but non-magnetic material. In this paper, we described sensitive quality an electric current coil sensor followed by the principal of Rogowskii coil on the low dielectric loss LTCC, change different line width, gap, line length at sensing parts and extinction parts.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.1
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• pp.103-113
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• 2003

We must enhance a fingerprint image to improve the performance of a fingerprint recognition. Because of this reason, many researches were achieved about the fingerprint image enhancement. Representative method is to use Gabor-Filter among them. However GF has the weakness which a processing hour takes long. In this paper, we proposed Half Gabor Filter (HGF) to enhance the fingerprint image fast in the on-line. The HGF, however, can make calculation much simpler, as well as both minutiae-extraction rate and recognition rate. On the other hand, the fingerprint image to enhance using HGF has almost same with the case effectiveness to apply GF. In this paper, we confirme it mathematically and experimentally.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.7
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• pp.418-426
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• 2013

With advantages of open spaces and existing HVAC facilities, subway station, if unexpected disastrous situation happens on the ground, can be used as a temporary safe place for evacuees. The main objective of this study is to establish a guideline on estimating evacuation capacity of the subway station and evaluating levels of service of evacuation for officials to control the situation. This guideline includes available spaces of the station, capacity of sanitary fixtures, and total number of passengers, etc. In this paper, we first analyzed the number of passengers of SMRT (Line 5~Line 8) during AM peak hour and then evaluated the number of passengers using toilets at that time. In addition, we calculated the seating capacity of subway stations on SMRT using the difference between the actual number of toilets and the estimated number of ones from the occupancy time of each toilet.

• Journal of Biosystems Engineering
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• v.30 no.3 s.110
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• pp.172-178
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• 2005

Grading and sorting an indeterminate form of agricultural products such as sweet potatoes and potatoes are a labor intensive job because its shape and size are various and complicate. It costs a great deal to sort sweet potato in an indeterminate forms. There is a great need for an automatic grader fur the potatoes. Machine vision is the promising solution for this purpose. The optical indices for qualifying weight and appearance quality such as shape, color, defects, etc. were obtained and an on-line sorting system was developed. The results are summarized as follows. Sorting system combined with an on-line inspection device was composed of 5 sections, human inspection, feeding, illumination chamber, image processing & control, and grading & discharging. The algorithms to compute geometrical parameters related to the external guality were developed and implemented for sorting the deformed sweet potatoes. Grading accuracy by image processing was $96.4\%$ and the processing capacity was 10,800 pieces per hour.

• Journal of the Korean Society for Heat Treatment
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• v.16 no.3
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• pp.141-147
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• 2003

The effects of heat treatment on the fatigue life and welding residual stress of welded plates were investigated in this study. The plates were welded by flux cored arc welding process, and post weld heat treated at $600^{\circ}C$ for 1 hour. The residual stresses of welded plates before and after post weld heat treatment were measured by hole drilling method. To measure the fatigue life of welded plates, low cycle fatigue tests under strain control and high cycle fatigue tests under load control were performed respectively, by using cylindrical specimens containing weld metal and heat affected zone. The obtained result shows that the post weld heat treatment reduces the residual stress, and resultantly changes the fatigue life of welded plate. Goodman diagrammatic analysis has also been performed to study the effect of post weld heat treatment on the high cycle fatigue life.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.967-974
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• 2000

By testing compressive strength, water absorption and water premeablity, to establish the standard of quality of waterproofing admixture of power type for concrete, we propose guide line as following ; $.$Setting time: more than 1 hour, within 10 hours $.$Slump: To be satisfied with request of user $.$Air content: To be satisfied with request of user $.$Safety: Without crack or deformation $.$Ratio of compressive strength: $\circled1$ At 3 days : more than plain specimen by 0.9 (An inorganic material) more than plain specimen by 0.4 (An inorganic material mixed organic) $\circled2$ At 7, 28 days : more than plain specimen by 1.0 $.$Ratio of water absorption Coefficient: $\circled1$An inorganic material: less than plain specimen by 1.0 $\circled2$ An inorganic material mixed organic : under than plain specimen by 0.8 $.$Ratio of water premeablity : $\circled1$ An inorganic material : less than plain specimen by 1.0 $\circled2$ An inorganic material mixed organic : under than plain specimen by 0.8

• Journal of Biosystems Engineering
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• v.32 no.3
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• pp.179-189
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• 2007

Most of the seeds of cucurbitaceous rootstock species used for grafting were mainly sown by hand. This study was carried out to develop an on-line discriminating algorithm of seed direction using machine vision and an automatic seeding system. The seeding system was composed of a supplying device, feeding device, machine vision system, reversing device, seeding device and system control section. Machine vision was composed of a color CCD camera, frame grabber, image inspection chamber, lighting and personal computer. The seed image was segmented into a region of seed part and background part using thresholding technique in which H value of HSI color coordinate system. A seed direction was discriminated by comparing position between the center of circumscribed rectangle to a seed and the center of seed image. It took about 49ms to identify and redirect seed. Line-up status of seed was good the more than 95% of a sowed seed. Seeding capacity of this system was shown to be 10,140 grains per hour, which is three times faster than that of a typical worker.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.3
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• pp.184-193
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• 2008

For environment-friendly fishery, the lead sinkers of octopus drift line were developed with the environmentfriendly sinker, and their characteristics and performance were investigated. To make the environmentfriendly sinker, the hydrate ceramic material was developed, and to increase the weight and strength, the iron power was added to it. The fishing hook was machine-made, and standardized, by using 60cm iron wire. For the manufacture of the sinker, the first, the mold was made, and then, hydrate ceramic material and water were quantitatively mixed. The mixture was poured into the mold prepared with a fishing hook already inserted, and had hardened for several hour, before it was taken out of the mold as a complete sinker. The sinkers were made in the 8 types ranging in weight from 150 to 500g, and their specific gravities were diverse from 2.871 to 6.637, which was 0.19 to 0.44 times lower than that of lead. The movement of the environment-friendly sinker by flume tank was possible in the weaker current speed than the similar lead sinker. In the coastal fishing grounds of Gangwon province, the comparison of catching efficiency was made between the improved fishing gears composed of the environment-friendly sinkers and artificial baits, and the current used fishing gears of lead sinkers and pig-fat baits. The result showed the tendency in which the improved fishing gears caught the bigger octopuses than the current used fishing gears. In the quantity and number of the fish catch per unit fishing gear, the improved fishing gear showed a little more catch than the current used fishing gear, regardless of the fishing area. However, the number of the improved fishing gears lost during fishing operation was similar to that of the current used fishing gears.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.159-162
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• 2001

In order to investigate the influence of sea condition on the catch fluctuation of long line for common octopus, octopus variabilis, the oceanographic factors. I. e., the wind direction, the wind speed, the age of moon and ebb tide and flood tide in the coastal waters of Yosu from Jan. 11 to Jul. 25 in 1997, and compared with the catches of common octopus, octopus variabilis by long line. The results obtained summerized as follows: 1) The catch of common octopus was highest in wind direction from SE and lowest in that from NW. The catch was highest at the wind speed of 2m/sec and decreased with increasing speed, over 2m/sec. 2) The catch of common octopus was highest at the day of neap tide and lowest at the mid day, from neap tide to spring tide. More strictly the catch was higher during days at which the current became rapid than during days at which the current became slow. The catch was higher always at flood tide than at ebb tide in all the days investigated and highest with in one hour from ebb tide.