• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.1
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• pp.17-23
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• 2009

This paper proposes a new type of MR(magnetorheological) fluid based suspension system and applies it to military vehicle for vibration control. The suspension system consists of gas spring and MR damper. The nonlinear behavior of spring characteristics is evaluated with respect to the wheel travel and damping force model due to viscosity and yield stress of MR fluid is derived. Subsequently, a military vehicle of 6WD is adopted for the integration of the MR suspension system and its nonlinear dynamic model is established by considering vertical, pitch and roll motion. Then, a sky-hook controller associated with semi-active actuating condition is designed to reduce the imposed vibration. In order to demonstrate the effectiveness of the proposed MR suspension system, computer simulation is undertaken showing vibration control performance such as roll angle and pitch angle evaluated under bump and random road profiles.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.353-355
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• 2007

피접지체의 접지는 전력설비의 절연파괴,낙뢰 등으로 전압이 침입할 경우 접지전극의 접지저항이 높으면 접지전극으로 유입되는 전류와 접지저항의 곱에 해당하는 접지전극의 전위가 상승하게 되므로 설비의 파손 인축의 피해 등이 발생 할 수 있다. 따라서 접지저항은 낮은 값으로 유지하는것이 필요하고 정기적으로 측정하여 관리하도록 규정하고 있다. 대표적인 접지저항측정방법으로는 3전극법(Fall of potential method)과 Hook-on 측정법이 있다. 그러나 3전극법은 측정하고자 하는 접지전극으로부터 일정한 거리에 전류를 흘려주고 이때 대지 전위를 측정 할 수 있는 2개의 보조전극 설치가 필수적이나 접지극과 접지선의 단자와는 설치 위치가 다르므로 접지전극의 설치점을 확인하기 곤란하고 건물내부, 지하철, 터널 등에는 보조전극의 설치가 거의 불가능하므로 처음 설치한 접지극의 접지저항측정관리에 어려움이 크다. 또한 Hook-on 측정법은 다중 접지 계통에 사용하는 방법으로 접지극이 수십 또는 수백개를 병렬로 연결한 경우 측정하고저 하는 접지그의 접지저항값에 비해 나머지 접지전극 전체의 합성저항이 무시할 수 있을 만큼 적은 경우에만 측정할 수 있으므로 건물이나 변전실 등 수개의 접지극이 설치된 경우는 사용할 수 없다. 본 연구는 보조전극을 설치하지 않고 측정하고자하는 접지전극 상호간의 전류분배 비율을 저항의 역수 비율로 하여 각각의 접지 전극의 접지저항값을 운전 중인 상태에서 간단하고 정확하게 측정할 수 있는 새로운 접지저항 측정 방법에 관한 연구이다.

• Korean Journal of Plant Resources
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• v.5 no.1
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• pp.31-35
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• 1992

The somatic chromosome numbers were counted to be 2n = 16 of Codonopsis lanceolata. Chromosomes 2 and 7 of Sokrisan and Koheung II has a hetero satellite on short arm. Chromosome 5 of Bakwoonsan showed homo satllite on short arms. Short arms of chromosomes 1 and 5 has homo satellite and short arms of chromosomes 2 and 7 has hetero satellite of Jilin.

• Journal of the Korean Home Economics Association
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• v.36 no.6
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• pp.57-70
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• 1998

For developing girls' brassiere, the survey on the actual wearing condition of brassiere for girls aged 9-15 if fulfilled. The findings of this study can be summarized as follows. 1) The starting age of the breast growth differs according to regions, schools, grades and body shape. Reason wearing brassiere is to sustain body shape. present brassiere type preferred most is tank-top. Motive wearing brassiere is based on the other's recommendation. Purchasing brassiere is performed largely by mother. 2) Few complaints appeared in the aspects of sewing, hook, loop, wire, wearing sense, touching sense, sweat absorption etc. Evaluation for the brassiere color and design is totally satisfied. When purchasing brassiere, beauty and color are important to all of girls. Yes or No of satisfaction for the wearing sense and comfort of brassiere is answered negatively. 3) Elementary school pupils preferred sport type, While middle school students showed an order as follows-wire

• Clinics in Shoulder and Elbow
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• v.5 no.1
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• pp.23-28
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• 2002

Purpose Displaced lateral end fracture of clavicle and acromioclavicular dislocation type Ⅲ∼Ⅵ may be required surgical treatment. Material and Methods : From May 1998 to March 2001, we operated with Welter plate with minimal incision by one surgeon. Immediately, pendulum and passive exercise was initiated after surgery. The shoulder function was evaluated using UCLA score. Average follow up was on 28(12∼45) months. Results : All 11 patients were regained satisfactory function. Average UCLA score was 31.9(29~35) at last follow up. Conclusion . The merit of Welter plate fixation with minimal incision is simple technique, reduced surgical time, smaller scar than large plate, strong fixation, early exercise, reduced implant failure. The disadvantage is expensive, skin irritatatation by long hook. But Welter plate fixation with minimal incision is a good method of internal fixation and excellent clinical result in surgical treatment of type H displaced lateral end fracture of the clavicle and type Ⅲ∼Ⅵ acromioclavicular dislocation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.120-128
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• 2019

It is very important to verify the seismic performance and stability of the power plant fixture in the domestic power plant, because earthquakes have increased in frequency around the world which resulted in the frequent occurrence of power plant damage caused by the failure of electric power facilities. In this study, through the on-site inspection of power plant fixation unit installed in domestic power plants, we carried out structural performance evaluation of the fixation unit anchor bolts installed on the concrete slabs. The field survey showed M12 J hook anchor bolts were used. Anchor bolt pullout and shear performance evaluation were performed based on ASTM E 488-96 standard. Moreover, artificial crack with the width of 0.5 mm was applied during the experiment based on ATM355.4 and ETAG 001. The comparison of M12 J hook anchor bolt pullout and shear test result to design value required in domestic and international design standard, show a satisfactory result. M12 J hook anchor pullout and shear performance was found to be about 35% and 7%, respectively, higher than the required design value.

• Clinics in Shoulder and Elbow
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• v.20 no.4
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• pp.201-207
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• 2017

Background: The blunted tip of a reusable with multiple uses can cause problems with the passing procedure in arthroscopic Bankart repair. This study assessed the advantage of Scorpion with a $70^{\circ}$ arthroscope in arthroscopic Bankart repair compared to hook typed suture passer. Methods: Scorpion in 19 patients, the hook type suture passer (conventional group) in 18 patients were used. All patients underwent the same procedure except for the type of suture passer used. Another different point of the procedure were telescopes and the number of portals used; three arthroscopic portals (posterior, anterorsuperiorlateral, and mid-anterior) and a $30^{\circ}$ arthroscope in the conventional group, but two portals and a $70^{\circ}$ arthroscope as well as the $30^{\circ}$ one in the Scorpion group. The surgery time and the surgical complications including an iatrogenic axillary nerve injury were recorded. Results: The Scorpion group showed a significant decrease in surgery time compared to the conventional group. In contrast to the conventional group, Scorpion provided an easy estimation of the exit of suture passing, no iatrogenic labral injury during the passing procedure with straight movement and the sharp tip of the knife installed. Iatrogenic supraspinatus injuries could be avoided when making an accessory anteosuperiorlateral portal due to the $70^{\circ}$ arthroscope. Conclusions: In arthroscopic Bankart repair, the use of the Scorpion suture passer and a $70^{\circ}$ arthroscope can reduce the surgery time, avoid unnecessary supraspinatus injury, and avoid iatrogenic axillary nerve damage through the relatively easy and precise suture passing and saving of the anterosuperior portal.

• Gut and Liver
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• v.12 no.6
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• pp.722-727
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• 2018

Background/Aims: Although endoscopic bilateral stent-instent placement is challenging, many recent studies have reported promising outcomes regarding technical success and endoscopic re-intervention. This study aimed to evaluate the technical accessibility of stent-in-stent placement using large cell-type stents in patients with inoperable malignant hilar biliary obstruction. Methods: Forty-three patients with inoperable malignant hilar biliary obstruction from four academic centers were prospectively enrolled from March 2013 to June 2015. Results: Bilateral stent-in-stent placement using two large cell-type stents was successfully performed in 88.4% of the patients (38/43). In four of the five cases with technical failure, the delivery sheath of the second stent became caught in the hook-cross-type vertex of the large cell of the first stent, and subsequent attempts to pass a guidewire and stent assembly through the mesh failed. Functional success was achieved in all cases of technical success. Stent occlusion occurred in 63.2% of the patients (24/38), with a median patient survival of 300 days. The median stent patency was 198 days. The stent patency rate was 82.9%, 63.1%, and 32.1% at 3, 6, and 12 months postoperatively, respectively. Endoscopic re-intervention was performed in 14 patients, whereas 10 underwent percutaneous drainage. Conclusions: Large cell-type stents for endoscopic bilateral stent-in-stent placement had acceptable functional success and stent patency when technically successful. However, the technical difficulty associated with the entanglement of the second stent delivery sheath in the hook-cross-type vertex of the first stent may preclude large cell-type stents from being considered as a dedicated standard tool for stent-in-stent placement.

• Journal of Species Research
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• v.12 no.3
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• pp.203-211
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• 2023

Five ciliate species of Euplotes were isolated from fresh and coastal water during a sampling survey to identify unrecorded ciliates in South Korea. Their morphology was investigated using live observation, protargol and "wet" silver nitrate staining methods. Brief descriptions and microphotographs of each species and a comparison with related species are provided. Euplotes focardii is characterized by an average size of 65×47 ㎛ after protargol impregnation, 6 dorsal and 3 ventral ridges and dorsal argyrome pattern of double-eurystomus type. Euplotes nobilii shows an average size of 34×20 ㎛ after protargol staining, 6 dorsal and 3 ventral ridges and dorsal argyrome pattern of double-patella type. Euplotes octocarinatus, the only freshwater species described in the present study, is characterized by an average size of 66×46 ㎛ after protargol impregnation, 6 dorsal and 3 ventral ridges and dorsal argyrome pattern of double-patella type. Euplotes petzi has an average size of 43×30 ㎛ after protargol staining, a macronucleus hook-shaped and dorsal argyrome pattern in double-patella type. Euplotes raikovi is characterized by an average size of 40×24 ㎛ after protargol staining, 6 dorsal and 3 ventral ridges and dorsal argyrome pattern of double-patella type.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.2
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• pp.83-94
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• 1994

Performance test result on prototype car equipped with low-band type active suspension system is reported. Control theory is explained first. Simulation for feasibility and parameter tuning, control module test using hydraulic exciter and test run, and performance evaluation of the test car on test track are reported successively. Emphasis was put on modification of control theory which caused many unexpected problems in actual implementation.