• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.2
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• pp.54-63
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• 2014

Corrugated steel plate structure, which is built by assembling corrugated steel plate segments with bolts on site and filling the surroundings with quality soil, is widely used for buried structures as a eco-corridors, small bridges, and closed conduits. This experimental study is dealt with the static and fatigue performance of bolt connected corrugated steel plates under flexural loading. The experimental variables to verify the fatigue performance are bolt diameters and detailing of connection such as washer and the corrugation dimension of specimens has a $400{\times}150$ mm. The experimental ultimate strength of specimens under static loading was higher than the theoretical strength and all specimen failed by a bearing and tearing failure of bolt hole of upper plate. Therefore, a fatigue tests of specimens had 6.0mm and 7.0mm thickness was conducted in which the load range was up to 209kN and 516kN, respectively. From the fatigue test, failure patterns are changed from plate bearing and tearing which is a typical failure pattern of static failure to a bearing failure of plate and shear failure of bolt, and experimental fatigue limit at $2{\times}10^6$cycles is about 85MPa.

• Journal of Industrial Technology
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• v.9
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• pp.21-28
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• 1989

For the study of the fatigue behavior, high-strength bolted connections on a small scale were manufactured, and carried on fatigue tests. Its experimental values were analysed by stress-fatigue life (S-N) curve. Three types of specimens : the base metal, the cireular hole and the welded sperimens had same net section were made. Through the same tests those experimental values were compared with those of the high-strength bolted conneetions. The results of these studies are as followings. It was found that the fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the high-strength bolted conneetions were much more about 14% and 16% than that of the base metal specimen. It was thought that this trend was due to frictional force increasing fatigue strength. It was known that fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the welded joints were less 29% and 21% than that of base metal specimen. It was thought that that trend was due to weld flaw. It was appeared that the fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the high-strength bolted connections were much more about 38% and 30% than that of welded joint. It was thought that it was due to both frictional force increasing the fatigue strength in bolted connections and weld flaw decreasing the fatigue strength in welded connections. It was found that the fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the B3 specimens were much more 2% and -2% than that of the B4 specimen. It was thought that that trend was due to the frictional force, which concerned with shape of specimen. It was known that the fatigue strength in $F_{n=100,000}$ and $F_{n=2,000,000}$ of the specimen with circular hole was less 61% and 65% than that of base metal. It was known that the allowable stress for bolted joint was higher than that of welded Joints. If that research is continued and more data are accumulated it can be expected that a basic pattern to provided the indicator of the fatigue design of the bolted connections of steel structures and persume the safety and lifeproof of existing structures is given.

• Journal of Sasang Constitutional Medicine
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• v.8 no.1
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• pp.295-317
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• 1996

It is researched to elucidate the effects of Taeumjowuitang(TE,太陰調胃湯), Sibimikwanjungtang(SE, 十二味寬中湯) and Yangkeogsanwhatang(SY,凉膈散火湯) on the obesity induced by gold thioglucose and the differentiation and growth of preadipocyte 3T3-L1 in the mouse. The result were as follows: 1. TE,SE and SY extracts improved the blood level of transaminase in the obese mouse induced by gold thioglucose. 2. TE,SE and SY extracts inhibited the increase of liver fat and body fat in the obese mouse induced by gold thioglucose. 3. TE,SE and SY extracts inhibited the increase of body weight in the obese mouse induced by gold thioglucose. 4. TE,SE and SY extracts inhibited the growth of undifferentiate preadipocyte 3T3-L1. 5. TE,SE and SY extracts showed inhibitory effect on the differentiation of preadipocyte 3T3-L1. The above results suggest that the TE,SE and SY extracts may be used on the obesity induced by the overgrowth and differentiation of adipocyte, and the accumulation of fat in liver and body.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.1
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• pp.49-59
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• 1984

Optimizing investigation of characteristics of underwater welding by a gravity type arc welding process was experimentally carried out by using six types of domestic coated welding electrodes for welding of domestic marine structural steel plates (KR Grade A-1, SWS41A, SWS41B,) in order to develop the underwater welding techniques in practical use. Main results obtained are summarized as follows: 1. The absorption speed of the coating of domestic coated lime titania type welding-electrode became constant at about 60 minutes in water and it was about 0.18%/min during initial 8 minutes of absorption time. 2. Thus, the immediate welding electrode could be used in underwater welding for such a short time in comparison with the joint strength of in-atmosphere-and on-water-welding by dry-, wet-or immediate-welding-electrode. 3. By bead appearance and X-ray inspection, ilmenite, limetitania and high titanium oxide types of electrodes were found better for underwater-welding of 10 mm KR Grade A-1 steel plates, while proper welding angle, current and electrode diameter were 6$0^{\circ}C$, above 160A and 4mm respectively under 28cm/min of welding speed. 4. The weld metal tensile strength or proof stress of underwater-welded-joints has a quadratic relationship with the heat input, and the optimal heat input zone is about 13 to 15KJ/cm for 10mm SWS41A steel plates, resulting from consideration upon both joint efficiency of above-100% and recovery of impact strength and strain. Meanwhile, the optimal heat input zone resulting from tension-tension fatigue limit above the base metal's of SWS41A plates is 16 to 19KJ/cm. Reliability of all the empirical equations reveals 95% confidence level. 6. The microstructure of the underwater welds of SES41A welded in such a zone has no weld defects such as hydrogen brittleness with supreme high hardness, since the HAZ-bond boundary area adjacent to both surface and base metal has only Hv400 max with the microstructure of fine martensite, bainite, pearlite and small amount of ferrite.

• Journal of Sasang Constitutional Medicine
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• v.8 no.1
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• pp.377-393
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• 1996

Lumbago is the common disease in the human, many people have been sicked the Lumbago. As the traditional methods of Lumbago treatment, acupuncture, moxibustion, herb medicines have been applied to a patient, nowadays, new methods have been applied physical remedy, Yakchim (Korean herb acupuncture) remedy, Chuna remedy to. This report was collected 73 Lumbago patients by name, sex, age, motive, symptoms, X-ray, CT, MRI, lRCT, Sasang constitution type, Sasang herb medicine, Yakchim, Chuna, period of remedy, satisfaction of remedy, at the "WooRee Korean Medical Clinic" during 21 months from Sep. 14, 1994 to May 25, 1996. And this report was studied about the distribution of the Sasang constitution type, the Sasang herb medicine, the effect, the period. The results were as follows: 1. Lumbago patients were distributed like that; Taeum-ln (太陰人) 47 (66.3 %), Soyang-In 16 (21.9 %), Soum-In (13.7 %), Taeyang-In (太陽人) 0. This was different from distribution of Donguisuseibowon (東醫壽世保元), Taeum-In (太陰人) 50%, Soyang-In (少陽人) 30 %, Soum-In (少陰人) 20 %, Taeyang-In (太陽人) little, this report shows that the number of Taeum-In (太陰人) is more than that of Donguisuseibowon and the number of Soum-In is less than that of Donguisuseibowon. 2. The average satisfaction of remedy was 60.3 %, Taeum-In's satisfaction was 66.0 %, Soum-In's satisfaction was 56.3 %, Soyang-In's satisfaction was 60.0 %. 3. The effective herb medicines were as follows, Soyang-In used the Hyong Bang Ji Hwang Tang (荊防地黃湯), Yuk Mi Ji Hwang Tang (六味地黃樓), Soum-In used the Sib Yi Mi Goan Jung Tang (十二味寬中湯), Taeum-In used the Chung Sim Yon Ja Tang (淸心蓮子陽), Chung Pae Sa Gan Tang (淸師爾肝湯), Yeol Da Han So Tang (熱多寒少湯). 4. The period of remedy was about 6 weeks. The period of remedy of each types was as follows, Taeum-In was about 5.7 weeks, Soum-In was about 6.8 weeks, Soyang-In was about 4.2 weeks. 5. The method of Lumbago remedy is divided three types, sprain Lumbago, Pyobyong (表病 : outside Syndromes) Libyong (裡病 : inside symdromes). Soum-In's methods are Pyobyong's ascending the Yang (陽), adding the Gi (氣) [升陽益氣], and Libyong's descending the inside Yim (裡陰) [裡陰降氣], Soyang-In's methods are Pyobyongs's decending the outside-Yim [表陰降氣], and Libyong's ascending the cool Yang (濟陽) [淸陽上升]. Taeum-In's methods are Pyobyong's ascending the Lung's Yang (肺陽升氣), and Libyong's colding the dried hot liver (淸肝燥熱). Taeyang's methods are strong the liver and making Yim. (補r肝生陰) 6. There are two methods for using the YakChim (Korean herb-acupuncture) by Sasang constitution medicine, one is to select the Yakchim, the other is to choice the point for appling the Yakchim. The first, to select the Yakchim, the other is follows; Soum-In can select the bee Venom, Soyang-In can select the H.O. (Hong Whoa 紅花), Taeum-In can select the I (Hodo 胡挑), V, O.K. (Ungdarn, 薦膽), Uwhang 牛黃, Sa-Hyang 麝香, etc., Palgang Yakchim (eight principles Korean herb-acupuncture (八剛藥鐵)) could made by abstracted Sasang herb medicine. The second, to choice the points for applying the Yakchim are used in the TaeGiuk Acupuncture method (太梗針法), Sacho (四焦, four warmer) by Sasang constritutional physiology and pathology.