• 한국터널지하공간학회 논문집
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• 제17권3호
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• pp.363-382
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• 2015

본 연구는 수치해석을 통하여 TBM 세그먼트의 분할 수와 인접한 링의 이격각도가 라이닝의 부재력에 어떤 영향을 미치는 살펴보았다. 수치해석은 Midas civil 2012+ 프로그램을 사용하였고, 모델링은 2링빔 스프링 모델을 이용하였다. TBM 세그먼드 부재력은 다양한 요소에 의해 결정된다. 본 논문에서는 세그먼트 분할 수와 분포를 제외한 다른 요소인 이음부 스프링 계수, 지반반력계수를 통제하고 특정한 분할 수와 분할 특성을 통해 case를 선정함으로써 분할 수와 분포와 같은 분할 특성이 부재력에 미치는 영향을 분석하였다. 이로써 TBM 세그먼트 시공 설계시 구조적으로 유리하거나 불리한 이음부 특성을 확인할 수 있다.

• Advances in concrete construction
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• 제13권 2호
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• pp.199-213
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• 2022

Experimental and discrete element approaches were used to examine the effects of F shape non-persistent joints on the failure behaviour of concrete under uniaxial compressive test. concrete specimens with dimensions of 200 cm×200 cm×50 cm were provided. Within the specimen, F shape non-persistent joint consisting three joints were provided. The large joint length was 6 cm, and the length of two small joints were 2 cm. Vertical distance between two small joints change from 1.5 cm to 4.5 cm with increment of 1.5 cm. In constant joint lengths, the angle of large joint change from 0° to 90° with increments of 30°. Totally 12 different models were tested under compression test. The axial load rate on the model was 0.05 mm/min. Concurrent with experimental tests, numerical simulation (Particle flow code in two dimension) were performed on the models containing F shape non-persistent joint. Distance between small joints and joint angles were similar to experimental one. the results indicated that the failure process was mostly governed by both of the Distance between small joints and joint angles. The axial loading rate on the model was 0.05 mm/min. The compressive strengths of the samples were related to the fracture pattern and failure mechanism of the discontinuities. Furthermore, it was shown that the compressive behaviour of discontinuities is related to the number of the induced tensile cracks which are increased by increasing the joint angle. In the first, there were only a few acoustic emission (AE) hits in the initial stage of loading, and then AE hits rapidly grow before the applied stress reached its peak. Furthermore, a large number of AE hits accompanied every stress drop. Finally, the failure pattern and failure strength are similar in both approaches i.e., the experimental testing and the numerical simulation approaches.

• 한국전기전자재료학회논문지
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• 제14권6호
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• pp.511-517
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• 2001

We evaluated the electrical properties of 37 multifilamentary jointed tapes processed by superconducting joint. In the superconducting joining method, a lap-joint was used. Tapes were selectively etched, and exposed superconducting cores of the two tapes were brought into contact with each other and then only the joined region was uniaxially pressed in the range of 1,000 to 2,50 MPa. The critical current ratio(CCR) and n-value of the jointed tape were evaluated as a function of uniaxial pressure and number of step in the contacting region. It was observed that the CCR was dependent on the number of step, but almost independent of uniaxial pressure. The highest critical current ratio and n-value were obtained to be 58% and 26%, respectively, for the jointed tape to the tape itself.

• 한국경영과학회지
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• 제24권1호
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• pp.49-58
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• 1999

A new channel access function is proposed to enhance the performance of the Joint CDMA/PRMA. It is obtained in consideration of the number of terminals in reservation mode and the number of terminals in contention mode whose probability distribution is estimated by applying pseudo Bayesian approach. Simulation results show that the performance of the Joint CDMA/PRMA can be improved by applying new channel access function under voice-only traffic and mixed voice/random-data traffic.

• Computers and Concrete
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• 제31권3호
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• pp.207-221
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• 2023

In this investigation, the interaction between opening space and neighboring joint has been examined by experimental test and Particle flow code in two dimension (PFC2D) simulation. Since, firs of all PFC was calibrated using Brazilian experimental test and uniaxial compression test. Secondly, diverse configurations of opening and neighboring joint were provided and tested by uniaxial test. 12 rectangular sample with dimension of 10 cm*10 cm was prepared from gypsum mixture. One quarter of tunnel and one and or two joint were drilled into the sample. Tunnel diameter was 5.5 cm. The angularities of joint in physical test were 0°, 45° and 90°. The angularities of joint in numerical simulation were 0°, 30°, 60°, -30°, -45°, -60° and its length were 2cm and 4cm. Loading rate was 0.016 m/s. Tensile strength of material was 4.5 MPa. Results shows that dominant type of crack which took place in the model was tensile cracks and or several shear bands develop within the model. The Final stress is minimum in the cases where oriented angle is negative. The failure stress decrease by decreasing the joint angle from 30° to 60°. In addition, the failure stress decrease by incrementing the joint angle from -30° to -60°. The failure stress was incremented by decreasing the number of notches. The failure stress was incremented by decreasing the joint length. The failure stress was incremented by decreasing the number of notches. Comparing experimental results and numerical one, showed that the failure stress is approximately identical in both conditions.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.226-231
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• 2004

Press fitting method for joining of a hybrid tube and steel ring with small teeth for automotive aluminum/composite hybrid propeller shaft was devised to improve reliability and to reduce manufacturing cost, compared to other joining methods such as an adhesively bonded joint, bolted joint or welded joint. To obtain high strength of the press fit joint, an optimal design method for the teeth was devised with respect to number and shape of the steel teeth. Torsional static, fatigue tests and finite element analysis of the press fit joint were performed with respect to experimental variables. The developed optimal design method predicted well the static torque capability and failure mode of the press fit joint. Also, it provided design guide line of press fit joint for improving torsional static and fatigue characteristics.

• 한방재활의학과학회지
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• 제20권4호
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• pp.33-49
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• 2010

Objectives : This study was designed to elucidate the anti-pathogenetic and curative effects of Gyehyeoldeungbokhap-bang(Jixietengfuge-fang, GCP) on Type II collagen-induced arthritis(CIA) in mice. Methods : In experiment, twenty four mices were divided into non-treated normal group(n=6), bovine type II collagen-induced control group(n=6), collagen immunized and treated two group medicated with extract of GCP(concentration of extraction: 200 mg/kg n=6, 400 mg/kg n=6) for 4 weeks after collagen immunization, Various experimental such as arthritis, incidence, index, total cell number of spleen, total cell number of peripheral lymph node(PLN), paw joint total cell number, analysis on the percentage of immunofluorescent cells of spleen in CIA induced mice, effects of inflammatory gene expression in spleen, PLN and paw joint of CIA mice, production of cytokine(IFN-${\gamma}$, IL-4, TNF-${\alpha}$, IL-6), analysis of rheumatoid factor(anti-collagen lgG, lgM level in serum) and histopathological study on the paw joint. The arthritis index, incidence were measured a week over 4 weeks after second boosting. Total cell number of spleen, peripheral lymph node, paw joint were measure after performed experiment over 7 weeks. Concentration of cytokine and rheumatoid factor in serum were measured after experiment finished. Histopathological study on the paw joint was measured after 40 days medicated with extract of GCP. Results : 1. Incidence of arthritis and index of arthritis were significantly decreased in treated group with 400 mg/kg. 2. Total cell number of spleen, PLN and paw joint were significantly decreased in treated group. 3. Analysis on the percentage of immunofluorescent cells of spleen in CIA induced mice were significantly controled compare with control group. 4. Effects of inflammatory gene expression in spleen, PLN and paw joint of CIA induced mice were significantly controled compare with control group. 5. IFN-${\gamma}$, IL-6, TNF-${\alpha}$, concentration($pg/m{\ell}$) in serum of treated group was significantly decreased compare with control group. But IL-4 was significantly increased. 6. lgM and lgG concentration($pg/m{\ell}$) in serum of treated group was significantly decreased compare with control group. 7. Histopathologically, suppurative and destructive lesion of synovial membrane, articular cartilage and subchondral bony tissue in treated group were alleviated compare with those of control group. Conclusions : Based on the results described above, it might be consider that Gyehyeoldeungbokhap-bang(Jixietengfuge-fang, GCP) has antiarthritic and analgesic effects and also inhibitory effects on the progression of collagen-induced arthritis mice.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.295-302
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• 2002

Shear strength of the rock joint is dependent on the roughness and the compressive strength of the joint surface, normal stress and etc. Roughness of the joint profile is described by JRC suggested by Barton and Choubey (1977). Choice of the JRC value is subjective. A number of studies have been carried out to quantify the JRC. Predicted shear strengths by Barton's Equation using the new quantification method of JRC suggested by Chun and Kim (2001) were compared results of shear tests and new criteria of shear strength which have a better accuracy to predict shear strength was suggested.

• 대한한의학회지
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• 제15권2호
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• pp.198-211
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• 1994

After giuing some anti-high blood pressure medicine of boiled-compressed fluid and 5-Kinds factors(Hydralazine, Verapamil, Clonidine, Furosemide and Hydrochlorothiazide with Kangsimsan to animals in single or together. I got the following conclusion in comparing blood-pressure and pulse of circulating system with urinating operation. 1. By joint-use of Kangsimsan and Hydralazine. it was found out that the effect of blood-pressure lowering continues longer in together-use than in single. And I coule see that the number of pulse increased. 2. By joint-use of Kangsimsan and Verapamil. the blood-pressure lowering operation was kept better in together-use than in single. the number of pulse was not affected any. 3. By joint-use of Kangsimsan and Clonidine the blood-pressure lowering operation was not found out any concrete result. 4. By joint-use of Kangsimsan and Furosemide. the Remarkble effect of Urinization was recognized to be much better in joint-use than in single. 5. By joint-use of Kangsimsan and Hydrochlorothiazide. the suppressing effect of urinization was recognized to be much better in joint-use than in single. Therefore in consideration of the above study and observation. when the joint-use of Kangsimsan and the blood-pressure lowering medicine. Hydralazine and Verapamil. the period of blood-pressure lowering was kept and I can conclude that in case of joint-use of Furosemide, a kind of good urinization. the effect of urinization by Furosemide is increased, but that of Hydrochlorothiazide is disturbed.

• 근관절건강학회지
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• 제4권1호
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• pp.74-86
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• 1997

This investigation has been conducted based on the medical chart of 344 patients who have been diagnosed of fibromyalgia syndrome during Oct. 9, 1996 through Nov. 20 at the Rheumatism Hospital of H. University located in Seoul. 280 which have been included in the analysis. 1. Only one patient was male in 280 patients, age distribution was from 28 to 76, in which the average age was 52.4. 2. Percentage of treatment duration was 6 months in 46.1%, 3 years in 22.1% and 2 years in 12.5%. Considering these results, it can be predicted that the number of patients might be increased and accumulated in the future. 3. Percentage of patients having primary fibromyalgia syndrome was 39.3%, having combination with osteoarthritis was 36.7% and the rest case have combination with rheumatoid arthritis at the same time. 4. The percentage of cases having patients 10-12 tender points was 37.1%, while the most of cases have pain at 12-19 tender points. The common locations of the tender point were at lateral epicondyle of elbow in 92.0%, at midpoint of upper border Trapezius in 84.8%, at upper part of scapula Supraspinatus in 82.9%, at medial fat pad proximal to the joint line knee in 81.85%, at intertransverse of $C_{5-7}$ Low cervical in 73.4% and at 2nd distal costochondral Junction 2nd rib in 72.0%. And most of the patients had joint functional disability at all in 47.1% with average 2.41 joint functional disability. 5. Age was not a variable influencing the number of tender points and the number of joint functional disability.