• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.613-617
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• 2001

The test items like as endurance, air leakage and oil endurance test is requested for reliability evaluation about O-ring which is a kind of core machinery accessories of semi-conduct manufacturing equipment. For verification of these, we design and manufactured a test system for endurance, air leakage and oil endurance of O-ring for semi-conduct manufacturing equipment, and also performed the test for two kinds of O-ring, as it were Viton and Kalretz. The characteristics of this test equipment consist in realization of the test conditions of semi-conduct manufacturing equipment and satisfying the test method. The test conditions are cut gas, vacuum grade, temperature and revolution numbers in the endurance test system, vacuum grade and temperature in the air leakage test system, temperature and time in the oil endurance test system. The separating test results for wearing which is an oil endurance test item, the wearing index of domestic produced Viton O-ring is higher than foreign product by 2%, wearing rate of Kalretz O-ring better than Viton O-ring by 17%, and particles existed in various place. The test result of air leakage which is measured through the RGA sensor used Helium, the vacuum grade was $10^-3$Torr. And the test result of oil endurance, the volume change rate was 7~15%. Hereafter, we intend to analysis the reliability test evaluation and to utilize for domestic manufacturing companies by establishing data base and developing reliability softwares.

• Journal of Applied Reliability
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• v.7 no.1
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• pp.31-43
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• 2007

The function of O-ring seals is to prevent leakage during the service life of the components in which they are installed. The life prediction of O-ring is very important at various industry fields. Generally, to evaluated the long-term performance of O-ring in severe environments has applied a life prediction technique based on accelerated life test (ALT). In this work, Accelerated thermal aging test(l20, 130, 140, $150^{\circ}C$) of O-ring was applied for life prediction of O-ring. The property changes after thermal aging test was measured using TGA, DSC, FT - IR, Video Microscope and SEM. Shape parameter and life prediction were obtained using MINITAB program.

• The Journal of Korean Medicine
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• v.16 no.2 s.30
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• pp.225-247
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• 1995

Using Bi-Digital O-Ring Test which was developed by Ohmura Toshiaki, constiution classification by the vegetables' was Measured by various muscle power measurement meters and the results are as follow: 1. Pinch Gauge (Model:pc5030HPG, Japan) is the gauge to measure finger power between the thumb and the second finger, Grip Strength Dynamometer (Model: T.K.K. 5101, Japan) is to measure the hand power (hand dynamometer), Back Strength Dynamometer (Model: T.K.K. 5102, Japan) is to measure back muscle strength, Vertical jump Meter (Model: T.K.K. 5106, Japan) is to measure the height of jump. The above gauges were and its result found that the radish, potato, carrot and cucumber can influence to muscle strength was not true. 2. When the physical constitution is distinguished by the O-Ring Test method, Taeyangin's rate appeared as average 21% although it was insisted that there will be only 0.03-0.1%. This means that the physical constitution but it appears accidently according to the examinee's emotion about the material such as vegetable etc. as favor or unfavor. 3. It was found that the result of O-Ring Test is the same at any time and at any place was not true. there is no reemergence character. 4. The import of O-Ring Test mehtod to the physical discrimination disregarded that the mental factor influences absolutely to the physical heath in the ideological physi cal constitution medical science. 5. 'O-Ring Test method is a objective judgement method.' is wrong judgement. As you see on the above result, Bi-Digital O-Ring Test set the changeable voluntary muscle as the standard of the judgument, that was first mistake logically, second in spite of leass influence of mental influence by the examiner and examinee than the vegetable discrimination influence, the test disregarded the influence. Third, only grasp of some material on hand can influence to the voluntary muscle was a wrong theory disregarding the physiology. Finally the misunderstaning his subjective view as an objective view in spite of examiner and examinee's strong influence. Therefore such kind of physical descrimination method must be sublated.

• Proceedings of the Korean Reliability Society Conference
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• 2006.05a
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• pp.48-54
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• 2006

In this thesis, accelerated life test (ALT) method and procedure for rubber O-ring are applied to assure specified reliability of the products at guaranteeing the life of the products. Rubber O-ring is parts that keep intensity or make machine operation smoothly on attrition portion of machine and is used to prevent that oil is leaked. Usually. Rubber O-ring used NBR that is copolymer of acrylonitrile and butadiene. this are superior oil resistance, heat resistance, durability of abrasion, cold resistance, chemical resistance etc. The accelerated life test model for rubber O-ring are developed using the relationship between stresses and life characteristics of products. Using the accelerated life test method and the acceleration life test equipment which is developed, we performed life test, collected life data and analyzed the results of tests. The proposed accelerated life test method and procedure may be extended and applied to testing similar kinds of products to reduce test times and costs of the tests remarkably.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.6 no.1
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• pp.149-163
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• 2000

The cells that make up the body continuously undergo cell division to maintain life, but stress and carcinogens, and physiological stimuli suppress immunological functions in the body and change cells to cancerous cells. The only way to overcome cancer is by treatment through early detection and proper diagnosis. However, because early stage of cancer shows subjective symptoms that are similar to those of other common illnesses, even doctors have difficulty separating cancer from common illnesses in its early stage. However, the Ki(bioenergy) present in our body recognizes and changes to the most minute changes in the body. This method of detecting the change in bioenergy to discover a disease in the early stage to raise treatment success is called the OBET: O-Ring, Bioenergy Test. This method, which is based on the theories of oriental medicine, focuses on tumors, especially malignant tumors, and has shown value in diagnosis and treatment, as witnessed in the clinical applications. The diagnosis method and cases of OBET: O-Ring, Bioenergy Test are presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.64-67
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• 2000

It is usual that the medical examination of human body need special knowledpe and equipments. Thus we have to spend Lime and energy on going to special place such as hospital where doctors and equipments are. Which often cause missing a good chance af medical treatment as well as giving us inconvenience. However many simple and convenient equipments were developed for checking our health conditions recently. O-ring test is accepted a3 one of useful methods to examine our heallb conditions. Also the test is recognized as a uscful means to judge, withoul any special equipment and medical knowledge, if some medical substances or foods are beneficial or harmful to our health. However, the judgement may be mcorrect because it depend on doctor's subjective point of view.In this study, we developed an automatic O-ring t a r mach~ne which enable us to check our health conditions objectively and quantitatively. The validity of the idea to develope the machine was proved by experiments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.182-188
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• 2016

A decoy is a weapon system that can protect vessels from an enemy's torpedo. Thus, the decoy should be able to operate in the field without any failure. Because the decoy can be inoperable once its sealing is broken and water permeates inside the system, the hermetic sealing capability considering the operational environment is mandatory. To be hermetically sealed, a rubber-type O-ring is generally used in a decoy system. The sealed performance of rubber-type products, however, tends to age and deteriorate with time. Therefore, the O-ring needs to be maintained or changed periodically. This paper proposes a method to estimate the proper maintenance period using the hardness and elongation percentage, which represents the performance of the O-ring product and test data from Accelerated Life Test (ALT) of the product. The O-ring used in this paper is a NBR type, and the temperature was chosen to be the main accelerating factor as referenced in many studies. The criteria for the failure of the O-ring was set for the product to be 50% degraded compared to the initial performance. In addition, the Korean standard KS M 6518 was adopted and referenced for the preparation of test samples and the calculation of estimates. The O-ring's predicted life was simulated by analyzing the test results from a computer program, and the optimized maintenance period for the product was determined.

• Journal of Sasang Constitutional Medicine
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• v.7 no.1
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• pp.69-101
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• 1995

Using Bi-Digital O-Ring Test which was developed by Ohmura Toshiaki, constitution classification by the vegetables' was measured by various muscle power measurement meters and the results are as follow : 1. Pinch guage (Model : pc5030HPG, Japan) is the guage to measure finger power between the thumb and second finger, Grip Strength Dynamometer (Model : T.K.K. 5101, Japan) is to measure the hand power (hand dynamometer), Back Strength dynamometer (Model : T.K.K. 5102, Japan)is to measue back muscle strength, Vertical Jump Meter (Model : T.K.K. 5106, Japan) is to measure the height of jump. The above guages were used and its result found that the radish, potato, carrot and cucumber can influence to the muscle strength was not true. 2. When the physical constitution is distinguished vy the O-Ring Test method, Taeyangin's rate appeared as average 21% although it was insistedthat there will be only 0.03-0.1%. This means that the influence power of vegetable doest not appear according to the physical constitution but it appears accidently according to the examinee's emotion about the material such as vegetable etc. as favor or unfavor. 3. It was found that the result of O-Ring Test is the same at any time and at any place was not true. there is no reemergence character. 4. The import of O-Ring Test method to the physical discriminatio disregarded that the mental facor influences absolutely to the physical heath in the ideological physical constitution medicla science. 5. 'O-Ring Test method is a objective judgement method'. is wrong judgement. As you see on the above result, Bi-Digital O-Ring Test set the changeable voluntary muscle as the standard of the judgement, that was first mistake logically, second in spite of leass influence of mental influence by the examiner and examinee than the vegetable discrimination influence, the test disregarded the influence. Thire, only grasp of some material on hand can influence to the voluntary was a wrong theory disregarding the physiology. Finally the misunderstaning his subjective view as an objective view in spite of examiner and examinee's strong influence. Therefore such kind of physical descrimination method must be sublated.

• Journal of Sasang Constitutional Medicine
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• v.18 no.3
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• pp.145-154
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• 2006

1. Purpose This study was performed to find the objective Sasang Constitutional Diagnosis, The O-ring test is thought to be one of the several methods to classify constitution. But the O-ring test has several problems. I studied the Sasang Constitutional Diagnosis which is used by Pinch-Guage and Herb Drugs for alternative methods. 2. Methods I tested 89 person's grasping power with changing the medical herb which is exist on person's another hand. conclusion of the test was compared with that of QSCC II to confirm the significance of this study. 3. Results and conclusions Soyangin group, Taeumin group, Male Soyangin goup, Male Taeumin group and Male group have a significant result on converting grades statistically.

• Geomechanics and Engineering
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• v.18 no.1
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• pp.29-39
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• 2019

In this paper, it was presented an investigation on the load-settlement and vertical stress analysis of the ring footings on the loose sand bed by conducting both laboratory model tests and numerical analyses. A total of twenty tests were conducted in geotechnical laboratory and numerical analyses of the test models were carried out using the finite element package Plaxis 3D to find the ultimate capacities of the ring footings. Moreover, the results obtained from both foregoing methods were compared with theoretical results given in the literature. The effects of the ring width on bearing capacity of the footings and vertical stresses along the depth were investigated. Consequently, the experimental observations are in a very good agreement with the numerical and theoretical results. The variation in the bearing capacity is little when $r_i/R_o$ <0.3. That means, when the ring width ratio, $r_i/R_o$, is equal to 0.3, this option can provide more economic solutions in the applications of the ring footings. Since, this corresponds to less concrete consumption in the ring footing design.