• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.228-235
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• 2019

The purpose of this study was to investigate the effect of 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise on VAS, ROM, isokinetic myofunction, and dynamic stability after surgery of modified brostrom operation in chronic ankle instability patients. The subjects of this study were 12 chronic ankle instability patients who underwent modified Brostrom operation(MBO) by the same doctor. 6 weeks' accelerated rehabilitation program is scheduled to perform for 60min, everyday, and also anti-gravity program performed for 15~30min, everyday. The visual analog scale(VSA) and significantly decreased(p<.001) and ROM in all of dorsal flexion, plantar flexion, inversion and eversion significantly increased(p<.05) after 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise. Both inversion and eversion peak torque at $60^{\circ}/sec$(p<.001, p<.01) and at $180^{\circ}/sec$(p<.001) significantly increased after 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise respectively. In muscle defect, although inversion(p<.01) and eversion(p<.001) at $60^{\circ}/sec$ and inversion(p<.01) at $180^{\circ}/sec$ significantly decreased, eversion at $180^{\circ}/sec$ tended to decrease but did not change significantly after 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise. The dynamic stability significantly increased after 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise(p<.001). These results suggest that 6 weeks' accelerated rehabilitation with anti-gravity treadmill exercise has positive effect of VAS, ROM, isokinetic myofunction, and dynamic stability after surgery of modified brostrom operation in chronic ankle instability patients. Therefore, we consider that the accelerated rehabilitation with anti-gravity treadmill exercise, which is safely and fast method, has effect on more faster recovery of ankle stability, play ground and normal daily activities.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.241-247
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• 2007

Purpose : Congenital muscular torticollis (CMT) is a common and benign congenital disorder of the musculoskeletal system in neonates and infants. The pathophysiology is that the sternocleidomastoid muscle (SCM) is shortened on the involved side by fibrosis, leading to ipsilateral tilt and contralateral rotation of the face and chin. In this study, we investigated the clinical features of CMT, the role of ultrasonography (USG) in prediction of prognoses and the clinical significance of early detection and treatment. Methods : Forty seven patients (M:F=31:16) were diagnosed as a CMT between March 2003 and May 2006. We reviewed age at diagnosis, physical findings, USG findings, treatment and therapeutic outcome from their medical records. Results : The median age at diagnosis was 90 days (18 days-9 years, 7 months) and the right side of neck was affected in more patients (right : left=26:21). Of 24 patients with a palpable neck mass, 21 had USG; 19 cases showed sternocleidomastoid tumor (SMT). In cases with no neck mass, USG was performed in 11 patients; seven had postural torticollis (POST), three had SMT and one had muscular torticollis (MT). Among 40 patients with follow-up, 36 had total resolution. There was negative correlation between the age at diagnosis and the recovery time, whereas the final outcome was not correlated with USG findings. However, the patients without positive findings in USG had earlier resolution (1 month vs 2.6 months, P=0.0008). The patients with SMT had earlier diagnosis and excellent outcomes. The patients with MT were delayed to diagnosis and had the longest time to resolve. Lastly, the patients with POST had delayed diagnoses, but they had excellent outcomes. Conclusion : Since the patients with delayed diagnoses, in despite of benign courses, may take a long time to resolve and rarely need surgical treatment, it is important to diagnose and treat early. This study showed that USG findings of the SCM may be used as predictive factors.

• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.279-288
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• 1999

The creep of concrete structures caused by variable stresses is generally calculated by step-by-step method based on the superposition of creep function. Although most practical application is carried out by this linear assumption. significant deviations between predictions and experiments have been observed when unloading takes place, that is. stress is reduced. This shows that the superposition of creep function does not describe accurately the effect of sustained compressive preload. The main purpose of this study is to propose a creep analysis model which is expressed with both creep function and creep recovery function where increase or decrease of stress is repeated. In these two function method, the creep behavior is modelled by using linear creep law for loading and creep recovery law for unloading. To apply two function method to time analysis of concrete structures, the calculation method of creep strain increment under varying stress is proposed. The calculation results based on the present method correlates very well with test data, but the conventional superposition method exhibits large deviation from test results. This paper provides a more accurate method for the time dependent analysis of concrete structures subjected to varying stress, i.e. increasing or decreasing stress. The present method may be efficiently employed in the revision of future concrete codes.

• The Korean Journal of Zoology
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• v.31 no.1
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• pp.35-48
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• 1988

This study was made to investigate the effect of testosterone and cyclic-AMP (cAMP) on rat epididymis. Peritoneai injections of testosterone and cAMP to rats were earned out The activities of acid phosphatase (ACP), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) were measured and ultrastructural changes of luminal epithelial cells were observed. As a result, the activity of ACP was significanily decreased on the third day, that of ALP on the fifth day and that of LDH on the seventh day respectively in castrated group. In addition, the activities of ACP and ALP were significanily increased when treated with testosterone for 5 days, that of LDH when treated with testosterone for 7 days. In case of cAMP and cAMP - theophylline injection, the activities of ACP and LDH were increased but the range of increase was of no significance. However a significant increase in the activity of ALP was seen on both cases. On electron microscopic examination, gradually deformed Golgi complex, destructed mitochondria and disrupted stereociha were observed in castrated group. In case of testosterone injection, disrupted Golgi complex, mitochondria and stereocilia showed recovery. When cAMP and cAMP-theophylline were injected as an alternative, various cytoplasmic organelles as well as Golgi com- plex were recovered but stereocilia remained unrecovered.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.1
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• pp.109-116
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• 2021

In order to replace mineral aggregate used as road pavement materials with steel slag aggregate, this present study evaluated mechanical properties of SMA Concrete mixtures using steel slag aggregate as oxidized slag from electric furnace in iron works. The variables of this experiment are the aggregate type of mineral and steel slag and the sieve sized of 10mm and 13mm. The physical properties inclu ding the specific gravity and absorption rate etc. of the slag aggregate mixtu res satisfied the KS standard as asphalt mixtu re. As a resu lt of evalu ating the mechanical properties of the asphalt mixtures, the optimum asphalt content of the slag aggregate mixtures were lower than that of the mineral aggregate mixtures, but other quality standards were all satisfied. In the deformation strength evaluation, the slag aggregate mixtures were measu red slightly higher than that of the mineral aggregate mixtu res, and the dynamic stability test satisfied the 2,000pass/mm standard value in all specimens. And, the moduli of resilient of the slag aggregate mixtures showed an improved value compared with the mineral aggregate mixtures. Therefore, as the resilient rate of the slag aggregate mixtures improved, it is speculated that there will be an effect of improving public performance according to the repeated traffic load of the vehicle.

• The Transactions of the Korea Information Processing Society
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• v.1 no.2
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• pp.184-193
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• 1994

This paper considers the Updating Minimum-weight Spanning Tree Problem(UMP), that is, the problem to update the Minimum-weight Spanning Tree(MST) in response to topology change of the network. This paper proposes the algorithm which reconstructs the MST after several links deleted and added. Its message complexity and its ideal-time complexity are Ο(m＋n log(t＋f)) and Ο(n＋n log(t＋f)) respectively, where n is the number of processors in the network, t(resp.f) is the number of added links (resp. the number of deleted links of the old MST), And m=t＋n if f=Ο, m=e (i.e. the number of links in the network after the topology change) otherwise. Moreover the last part of this paper touches in the algorithm which deals with deletion and addition of processors as well as links.

• Transactions of Materials Processing
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• v.14 no.5 s.77
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• pp.423-431
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• 2005

In this paper, a systematic attempt for estimating geometric dimensions of cold forgings is made by finite element method and a practical approach is presented. In the approach, the forging process is simulated by a rigid-plastic finite element method under the assumption that the die is rigid. With the information obtained from the forging simulation, die structural analysis and springback analysis of the material are carried out. In the springback analysis, both mechanical load and thermal load are considered. The mechanical load is applied by unloading the forming load elastically and the thermal load is by cooling the increased temperature due to the plastic work to the room temperature. All the results are added to predict the final dimensions of the cold forged product. The predicted dimensions are compared with the experiments. The comparison has revealed that predicted results are acceptable in the application sense.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.102-102
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• 2011

레이온 섬유는 dry한 촉감, 고광택, 드레이프성 등 의류 분야에서 요구하는 많은 장점들을 가지고 있으나 타 섬유 소재에 비해 소비량이 적은 것은 합섬이나 면/울 제품에 비해 상대적으로 제품 가격이 높고, 형태안정성이 취약하여 정장 및 캐주얼의 겉감 용도로 쓰기에는 성능 보완이 필요하다. 또한 염색가공 공정에서 구김발생이 많으며, 열고정이 쉽게 이루어지지 않아 습윤강도와 탄성 회복률이 낮아 변형이 쉽게 발생된다. 이에 본 연구에서는 합섬의 장점을 그대로 유지하면서 레이온 섬유가 갖는 고비중과 우수한 드레이프성과 유연한 질감으로 소프트 터치를 발현하는 특수한 레이온 대체 소재를 실현하고자 하였다. 직물에서 드레이프성과 은은한 광택을 확보하기 위해서는 폴리머단계에서 비중과 광택을 발현할 수 있는 무기입자 중 비중이 높고, 중합 후 폴리머 내에서 광택을 유지하는 입자의 선택이 필요한데 본 실험에서는 $BaSO_4$를 이용하여 PET dope액과 중합한 후 용융 방사하여 고비중 폴리에스테르사(100/48)를 제조하였다. 고비중 폴리에스테르사를 이용하여 폭 58inch, 밀도 92T, 중량 324.8g/yd 직물로 제직하여 그에 따른 태를 측정하였다. 태측정기(KES-FB, KATO TECH CO)를 이용하여 인장 & 전단강도, 굽힘강도, 압축강도, 표면측정 시험 결과 $BaSO_4$ 2% 첨가한 원단의 드레이프성이 우수한 것을 확인할 수 있었다.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.153-162
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• 2003

The transformation of the Italian retailing has permitted, in the last ten years, a quick modification of the strategic groups' weight at a distributive level. Such change regards the redesign of the competitive assets that sees as protagonist both the main foreign big multiple chains and the Italian retailing, characterized by small dependent enterprises. The analysis is focused on the solutions that independent retailers are adopting in order to strengthen their competitive ability in relation to the aforementioned prospective entrance of foreign distributors in the domestic market. In particular, the most commonly adopted strategic alternative are analysed, in an attempt to characterize the development models that can emerge. The paper presents a case of possible successful solution adopted by some independent retailers for a competitiveness recovery without sacrificing the enterprise's property and autonomy.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.101-107
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• 2009

Actuators using shape memory alloys use the one-way shape recovery stress. But when external load is applied the accumulated plastic strain induced by repeated deformation is the factor of generation of uncorrect recovery stress and unreliability. To solve this problem, two-way shape memory effect (TWSME) is considered. TWSME induced by plastic deformation have advantages including simple heating cycle without external force and enough recovery force for using actuators. but there is no research on cylinder-type or tube-type shape memory alloy actuators using two-way shape memory effect until now. Therefore in this study, characteristics of two-way shape memory effect is verified through the compression experiments using cylinder-type and tube-type specimens.