• Journal of the KSME
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• v.25 no.3
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• pp.198-203
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• 1985

제동시 균형 문제나 약간 무거운 조향력등의 전륜구동장치을 설계하기 위한 단점들은 Negative 또는 Zero scrub Radius 의 현가장치를 가능케 하는 이론적 기술적 보완 및 해결이 되고 또한 X형 브레이크 파이프 개발로 한 회로 파열에서도 더욱 안정된 제동을 할 수 있게 된다. 따라서 (1) 중. 소형 승용차에서 절대적 비중을 차지하고 있는 실내 유효공간을 훨씬 크게할 수 있는 점 (2) 후륜구동에 비해 손쉽고 갑싸게 4륜 독립 현가장치가 가능하기 때문에 승차감에서 탁월한 개선이 이루어 진다는 점 (3) 우수한 직진(방향) 안정성과 선회성능을 얻을 수 있는 점 (4) 경량화 및 전동(轉動) 손실 감소에 따른 연비 향상 등의 커다란 장점으로 전륜구동차는 기술적인 면에서 후륜구동차에 비하여 그 격을 달리하고 있으며 몇 년 전부터 모든 자동차 회사가 신규 설계 개발중인 차는 전륜구동차로 밝혀지고 있으며 사용자의 전륜구동차에 대한 선호도는 계속 크게 증가할 것으로 보인다.

• Journal of Korean Foot and Ankle Society
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• v.4 no.2
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• pp.87-92
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• 2000

The tendinous ends of neglected achilles tendon rupture tend to retract and separate with atrophy due to gastrosoleus muscle contracture, leaving a wide gap occupied with fibroadipose scar tissue. It is almost impossible to perform simple end-to-end anastomosis after the intervening scar tissue being excised. Therefore many surgical procedures have been proposed to reconstruct the large gap. We treated three such cases by V-Y advancement flap and double Krackow suture technique, and their postoperative strength of triceps surae were evaluated with Cybex isokinetic strength testing. All patients returned to preinjury activities with satisfaction, but the ankle plantar flexor power showed about 20-30% deficit.

• Journal of Chest Surgery
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• v.34 no.11
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• pp.865-869
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• 2001

Operations for extensive aortic aneurysm are generally performed as staged operations with or without elephant trunk technique. However, we must consider single stage replacement in cases that are unsuitable for elephant trunk technique. We report a case of successful sing1e stage replacement of the entire thoracic aorta from the aortic valve to the level of diaphragm. The patient was a 35-year-old male who had Marfanoid features and had previously undergone replacement of the ascending aorta for aortic dissection. He recovered without neurologic complication and was discharged on 29th day after the operation. .

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.2
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• pp.103-109
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• 2001

In this paper, the prestressing order of tendons is studied to minimize a bursting force of an anchorage. The bursting forces is a primary factor of anchorage failures. The forces of the anchorage depend on the prestressing order and size of the tendons, if a lot of tendons are introduced to the anchorage. Many studies have been made to analyze the bursting force of the anchorage. However, the studies have been limited to the bursting forces of the anchorage having one or two tendons. PSC box girder bridges usually have a lot of tendons. And the difference of the bursting forces lies in the prestressing order of the tendons. As a result of the lack of studies on the prestressing order for the bridges, the order depends on the designer's intuition and experiences. It may be stated that this study should be useful for determining the reasonable prestressing order of tendons for the PSC box girder bridges.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.2
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• pp.79-84
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• 2010

Purpose: In patients with meniscal tear with degenerative arthritis, controversy remains as to whether arthroscopic menisectomy is worthwhile or not. The purpose of this study was to evaluate the effect of arthroscopic medial meniscectomy in degenerative arthritis of the knee with meniscal tear. We also intended to identify pertinent indications and risk factors. Materials and Methods: 287 patients underwent arthroscopic medial meniscectomy from 2006 to 2008; 103 patients who had Kellgren-Lawrence grade II, III arthritis of the knee, were over 50 years old, and had minimum 1 year follow-up, were analyzed in this study. Clinical assessment was performed retrospectively using the arthroscopic surgery database, medical records, questionnires and interviews. Assessment included visual analogue scale (VAS) scores and Lysholm scores. Results: The mean Lysholm score increased from 69 to 85 after surgery. The mean VAS score improved from 7 to 3.1 after surgery. Kellgren-Lawrence grade II group and group with trauma history showed significant improvement of pain and function compared with grade III and group without trauma history. Outerbridge grade I showed significantly more improvement of pain than grade III and IV. Multiple regression analysis showed that trauma history and Outerbridge grade affect the improvement of Lysholm score. Conclusion: In one year follow-up, arthroscopic medial menisectomy can improve pain and function of patients in Kellgren-Lawrence grade II, III degenerative arthritis of the knee. We could expect good results especially in group with low Kellgren-Lawrence grade, trauma history, and mild articular cartilage lesion.

• Restorative Dentistry and Endodontics
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• v.35 no.6
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• pp.492-496
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• 2010

Coronal discoloration is a common sequela to traumatic injuries. In subluxation cases, although the injury is not strong enough to rupture the apical vessels, discoloration may appear by tearing thin walls or occluding small capillaries. In absence of infection pulpal regeneration can occur, and as a result discoloration may completely or partially subside. But judging pulpal status by coronal discoloration can be dangerous and it may lead to unnecessary treatment. This case presents coronal discoloration and recovery following traumatic injury of maxillary anterior teeth. In diagnosing traumatized teeth routine cold tests or electric pulp tests are known to be unreliable, but with the aid of ultrasound doppler imaging, assessing pulp vitality of traumatized teeth can be more accurate.

• Clinics in Shoulder and Elbow
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• v.12 no.2
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• pp.207-214
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• 2009

Purpose: In arthroscopic rotator cuff repairs there are generally weak link in tendon suture interface, arthroscopic rotator cuff repairs can have higher retear rates than open repairs. The purpose of this study was to compare the strength of UU (Ulsan University) suture than open modified MA (Mason-Allen) suture when suture anchored into bone. Materials and Methods: The human supraspinatus tendons were harvested from the shoulder of the cadaver and split in 2 times, producing four tendons per one shoulder, for a total of 24 specimens. Two suture configurations (UU, MA) were randomized and checked on each set of tendons. Specimens were cyclically loaded under force control between 5 and 30 N at 0.25 Hz for fifty cycles. Each specimen was loaded to failure under displacement control at 1 mm/sec. Cyclic elongation, peak to peak displacement, stiffness, ultimate tensile load, mode of failure were checked. Results: No significant difference was found between two suture configuration with respect to peak to peak displacement, cyclic elongation, and stiffness. With regard to ultimate failure load, there were no significant difference statistically between the UU suture and modified MA suture (109.4 N, 110.6 N). The most common mode of failure between both sutures was suture pull-out through the tendon. Conclusion: The UU suture and modified MA suture produced similar biomechanical properties.

• Journal of the Korean Society of Food Culture
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• v.8 no.3
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• pp.267-274
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• 1993

This study was aimed to investigate the changes in textural properties of Korean radish and relevant chemical, enzymatic activities during salting. During salting, pH was decreased and total acidity was increased. The maximum compression and puncture forces of Korean radish were decreased significantly whereas cutting force was increased. From the force-distance curves, the break point and maximum force point disappeared in salted Korean radish whereas these appeared apparently in fresh one. Also, the number of peak obtained by three types of test from salted Korean radish was decreased. Hot water soluble pectin and 0.4% Na-hexametaphosphate soluble pectin were increased whereas 0.05 N-HCl soluble pectin were decreased significantly. Polygalacturonase activity were increased in Korean radish solid(RS) and Korean radish juice(RJ) until 4 days of salting. Pectin esterase activity were decreased in RS and RJ. Cx-cellulase activity did not appear initially, however, they began to show their activities after 2 days of salting and were increased in RJ although it was low.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.469-485
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• 2016

The failure of rock mass around deep tunnel, different from shallow tunnel largely affected by discontinuities, is dominated by magnitudes and directions of stresses, and the failures dominated by stresses can be divided into ductile and brittle features according to the conditions of stresses and the characteristics of rock mass. It is important to know the range and the depth of the V-shaped notch type failure resulted from the brittle failure, such as spalling, slabbing and rock burst, because they are the main factors for the design of excavation and support of deep tunnels. The main features of brittle failure are that it consists of cohesion loss and friction mobilization according to the stress condition, and is progressive. In this paper, a three-dimensional numerical model has been developed in order to simulate the brittle behavior of rock mass around deep tunnel by introducing the bi-linear failure envelope cut off, elastic-elastoplastic coupling and gradual spread of elastoplastic regions. By performing a series of numerical analyses, it is shown that the depths of failure estimated by this model coincide with an empirical relation from a case study.

• Journal of Biomedical Engineering Research
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• v.21 no.6
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• pp.567-573
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• 2000

뇌동맥류는 뇌혈관의 일부가 풍선처럼 부풀어나는 혈관계 질환이며 뇌동맥류의 파열은 사망이나 심각한 후유 장애를 야기한다. 뇌동맥류의 다양한 발생 원인 중 혈관 내부의 혈류의 유동이 중요한 인자로 의심된다. 뇌동맥류의 형성에 미치는 혈류역학적 인자를 규명하기 위해 내경동맥에서 발생한 환자의 내경 동맥류 CT 사진을 이용하여 내경동맥류 모델을 제작하고, 모델 내부의 혈류유동장을 입자영상속도계를 이용하여 측정하였다. 동맥류가 발생한 내경동맥류 모델에서는 동맥류 원위부 목(distal neck)쪽과 반대쪽 내경동맥 벽에서 전단응력이 높게 나타났다. 동맥류 발생에 미치는 혈류역학적 인자를 규명하기 위해 동맥류를 제거한 내경모델을 제작하여 맥동유동에서 내부 유동장을 측정하였다. 심실수축기 동안 휘어진 내경동맥의 바깥쪽 벽에서 혈류의 혈관벽 부딪힘이 관찰되었으며 심실이완기 초반에도 이는 계속 유지되었다. 내경 동맥 내부의 부차적 유동특성을 연구하기 위해 동맥류 발생 위치에서 혈관 축과 수직인 평면의 유동장이 측정되었다. 혈관 단면에서는 휘어진 혈관의 바깥쪽에서 안쪽으로 시계방향의 와류가 형성되었으며, 이로 인해 혈관벽 바깥쪽과 시계방향으로 90도 정도 지역에서 전단응력이 높게 나타났다. 혈류 유동 특성과 동맥류 발생위치를 비교해 보면, 혈류의 혈관벽 부딪힘이 관찰되는 위치와 부차적 유동에 의해 전단응력이 크게 나타난 지역은 동맥류의 발생위치와 일치하였다. 따라서 혈류의 혈관벽 부딪힘과 부차적 유동에 의한 전단력이 동맥류 발생의 혈류역학적 요인으로 의심된다.