• Journal of the Korean Arthroscopy Society
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• v.11 no.2
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• pp.122-127
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• 2007

Purpose: To know about the clinical characteristics such as causes, types, associated injuries and treatment of the lateral meniscus injuries. Materials and Methods: Retrospective analysis was performed for 129 lateral meniscus tears which were divided into 2 groups, Non-discoid and Discoid. Analysis included age and sex distribution, causes of injury, types and location of tear, associated injuries, and methods of treatment. Results: Both Non-discoid and Discoid were prevalent in man and Discoid group was equally distributed through 2nd to 5th decades and Non-discoid group was more prevalent in 4th to 5th decades. Sports injury was the most common cause in both groups and the Nondiscoid group tended to sustain minor injuries compared to Discoid group. Complex tear and body was most common type and site of tear in both groups. Associated injuries were common in Non-discoid group and isolated injuries were common in Discoid group. Partial meniscectomy was commonly done in Non-discoid group and subtotal meniscectomy in Discoid group based on the types of tear. Conclusion: Non-discoid and Discoid lateral meniscus injuries are similar in types and sites of injuries but different in causes of injury, associated injuries and methods of treatment. Therefore, proper diagnosis and treatment would be necessary according to the characteristics.

• 대한관절경학회:학술대회논문집
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• 2006.11a
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• pp.104-105
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• 2006

• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.58-66
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• 1979

동력경운기용 두류의 무경운 파종기에 부착하여 사용하는 구절기중에서 소요견인력이 작고 구절작업정도가 양호한 구절기의 개발을 위한 기초자료를 얻기 위하여 구동식 토조에 인공강토를 채우고 원판형 및 호우형 구절기의 소요견인력과 이에 영향을 미치는 인자들의 관계를 구명코자 실내모형 확험을 실시하여 다음과 같은 결과를 얻었다. 원판형 구절기에 대하여 직경별로 조립각을 $8^{\circ}$ 와 $16^{\circ}$, 경심을 3 cm 와 6cm로 변화시키면서 2.75cm/sec의 속도로 견인력을 측정한 결과 원판의 직경이 약 28cm인 경우에 견인력이 최소로 나타났고, 직경이 이보다 크거나 작은 때는 견인력이 증가하는 경향을 나타냈으며 비저항도 대체로 비슷한 경향이었으나 원판의 직경이 약 30cm 일 때 최소로 나타났다. 종자파종의 심도조절을 목적으로 작구심(3cm 및 6 cm)과 견인력과의 관계를 조사하였던바, 경심과 견인력과의 관계는 거의 직선적인 변화를 나타냈으며 견인력에 영향을 미치는 인자중에서 경심의 영향이 가장 컸음을 알 수 있었다. 일반적으로 조립각 미 주행속도에 별 영향없이 경심 3cm 및 6 cm 공히 견인력은 직경 약 28 cm에서 , 비저항은 약 30cm에서 최소의 값을 나타내었다. 파종기의 작업성능과 관계가 깊은 주행속도 및 파시의 조절을 목적으로 원판의 조립각과 주행속도가 견인력에 미치는 영향을 조사했던 바, 조립각과 주행속도가 증가함에 따라 모두 견인력이 증가하는 경향을 나타내었으나 견인력에 미치는 영향은 주행속도가 더욱 크게 나타났다. 원판형 구절기와 호우형 구절기를 비교하기 위하여 쐐기각이$16^{\circ}$ 이고 리프트 각이 $20^{\circ}$ 인 호우형 구절기와 조건이 비슷한 조립각$16^{\circ}$ 의 원판형 구절기의 견인특성을 비교한 결과 직경 30cm 인 원판형의 경우는 비저항이 0.35-0.5kg/$cm^2$인데 비해 호우형의 경우는 0.71-1.02kg/$cm^2$로 나타나 호우형의 견인저항력이 평균 2 배정도 크게 나타났고 작구상태고 원판형의 경우보다 불량하였다.

• Journal of the Korean Arthroscopy Society
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• v.16 no.1
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• pp.60-65
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• 2012

Although the lateral discoid meniscus has been observed frequently, the medial discoid meniscus is an extremely rare anomaly. The incidence of lateral discoid menisci ranges from 1.4% to 15.5% and the incidence of medial discoid menisci ranges from 0.06% to 0.3%. We present 1 patient of bilateral medial discoid menisci with tear on left side and 1 patient of unilateral medial discoid meniscus with tear, that were diagnosed by magnetic resonance imaging (MRI) and arthroscopy. We performed partial meniscectomy on 2 cases of symptomatic medial discoid menisci under arthroscopy and meniscus-related symptoms were relieved. We report 3 cases of 2 patients with medial discoid meniscus.

• Journal of the Korean Vacuum Society
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• v.12 no.2
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• pp.79-85
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• 2003

Experimental investigations are performed for the rarefied gas flows in a multi-stage disk-type drag pump. The pump considered in the present study consists of grooved rotors and stators. The flow-meter method is adopted to calculate the pumping speed. Compression ratios and pumping speeds for the nitrogen gas are measured under the outlet pressure range of 0.13∼533 Pa. The present experimental data show the leak-limited value of the compression ratio in the molecular transition region. The rotational speed of the pump is 24,000rpm, and nitrogen is used as a test gas. The pumping characteristics of various drag pumps are performed. The inlet pressures are measured for various outlet pressures of the test pump. The ultimate pressures for zero throughput are measured for three-stage, two-stage and single-stage disk-type, respectively.

• Transactions of the Korean Society of Mechanical Engineers
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• v.6 no.2
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• pp.176-182
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• 1982

이 논문에서는 평판의 배선형 해석에 대한 Berger의 방정식을 쉘좌표가 직교곡선좌표계로 표시 되는 Shallow 쉘에 대하여 일반화하여 운동방정식을 유도하였다. 해석의 예로서, 이 방정식을 사용하여 고정된 경계를 가진 원판과 Shallow 구쉘에 대한 배선형 진동문제를 해석하였으며, 정력학의 문제로서 원판이 동심원내에 균일하중을 받을때와 중심에 집중하중을 받을 때의 large deflection에 대하여 고찰하였고 나중문제에 대한 수치해를 구하였다.

• Journal of the Korean Vacuum Society
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• v.18 no.4
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• pp.272-280
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• 2009

In this study is performed to investigate the pumping characteristics of three-stage disk-type molecular drag pump (DTDP). The experiments are measured using five vacuum pressure gauges in the positions for rotors of DTDP. The experimented DTDP is consisted of three rotors and four stator. In the DTDP, spiral channels of three rotors are cut on the both upper surface and lower surface of a rotating disk, and corresponding stator is a planar disk. The experiments are performed in the outlet pressure range of $0.2{\sim}533\;Pa$. The pressure of each rotors are measured under the various condition of outlet pressure and throughputs, and nitrogen gas is used for test gas. In the numerical study, the pumping characteristics of each rotor are studied for the variation of throughputs in the all rotating channel. Pressure contour and velocity are obtained by the numerical simulation.

• Korean Journal of Agricultural Science
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• v.5 no.2
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• pp.149-157
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• 1978

This study was carried out to obtain basic data for the type selection of furrow openers for the no-tillage soybean planter trailed by the two-wheel tractor from the standpoint of minimum draft and good performance of furrowing. For this study, two models of furrow opener, hoe and disc type, were tested on the artificial soil stuffed in the moving soil bin. The results obtained were as follows. In the case of disc furrow opener, the drafts were measured according to various diameters of discs under the condition of disc angle $8^{\circ}$ and $16^{\circ}$, working depth 3cm and 6cm, working speed 2.75cm/sec. Minimum draft appeared when the diameter of disc was about 28cm and the drafts increased as the diameter of discs became larger or smaller than this diameter. Specific draft showed almost same tendencies as above but showed the minimum when the diameter was about 30cm. For the purpose of controlling the seeding depth, the relationships between draft and working depths, 3cm and 6cm, were tested. The variations of draft concerning the various working depths showed linear changes and were affected in higher degree by depths than other factors. There were general tendencies at both working depths, 3cm and 6cm, that total draft showed the minimum with the disc diameter of about 28cm and specific draft showed it with the disc diameter of about 30cm regardless of disc angle and working speed. For the purpose of controlling the working width and speed, the relationships among drafts, disc angle and working speed were investigated and there were general tendencies that the draft increased as the angle and speed were increased and the draft was affected more by speed than by angle. To compare the hoe-type with disc-type opener, the specific drafts of hoe openers were compared with those of disc opener of $16^{\circ}$ angle and 30cm diameter. The specific draft of disc-type opener with the diameter of 30cm was $0.35{\sim}0.5kg/cm^2$, while $0.71{\sim}1.02kg/cm^2$ in the case of hoe type with the lift angle of $20^{\circ}$ which is 2 times as much as that of disc type in average value. And the furrows opened by disc openers were cleaner than those opened by hoe openers.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.4
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• pp.434-438
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• 2001

Piezoelectric torsional transducers have been fabricated to generate torsional waves in a rod. The principle of generating torsional wane is based on the use of the circumferential shear motion derived by axial voltage exerted on the piezoelectric disk poled in the circumferential direction. The natural frequency or the piezoelctric torsional dish has been reduced by fabricating Langevin-type torsional transducers. The natural frequecies of the fabricated transducers have been measured and have shown good agreement with the characteristics predicted by analysis.

• Journal of the Korean Arthroscopy Society
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• v.15 no.1
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• pp.7-12
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• 2011

Purpose: We purposed to evaluate clinical results after undergoing arthrocopic surgery of lateral discoid meniscus in children. Materials and Methods: Retrospective evaluation was executed for the 21 cases which showed abnormal findings of knee joint due to lateral discoid meniscus, from Janunary 1 1999 to December 30 2007. Average observation period was 38.4 months (14months~60 months), and average age was 9.5 years old (7~12 years old). The major clinical findings for knee joint extension limitations were the most common with 11 cases, and there were 8 cases of knee joint pain, 6 cases of snapping, and 10 cases of gait abnormality. The forms of lateral discoid meniscus were 14 cases of complete type, 5 cases of incomplete type, and 2 cases of Wrisberg type. All patient had arthroscopic partial menisectomy and some patient who had meniscus tear had arthroscopic meniscus repair. The clinical results were evaluated using Ikeuchi grading system, and the change of knee joint was observed through routine radiography. Results: The peripheral hypermobility of lateral disciform meniscus was observed in 7 cases. The peripheral tear was observed in 4 cases, where partial menisectomy was along with suture at the same time. The final clinical results were 5 cases of Excellent, 12 cases of Good, 4 cases of Fair. Radiologically, there were 5 cases of subchondral sclerosis and narrowness of hardness at the lateral knee joint, and osteochondritis occurred at the joint facet of external femur in 1 case. In clinical result, meanwhile, there were 20 cases of normal or almost normal and only 1 case of abnormal in IKDC score. Conclusion: Knee joint arthroscopic partial menisectomy for treatment of lateral discoid meniscus is useful, and when accompanied by peripheral disruption, suture is thought to be necessary.