• KIPS Transactions on Software and Data Engineering
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• v.12 no.5
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• pp.237-242
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• 2023

Research on high-performance walking robots is being actively conducted, and quadruped walking robots are receiving a lot of attention due to their excellent mobility and adaptability on uneven terrain, but they are difficult to introduce and utilize due to high cost. In this paper, to increase utilization by applying intelligent functions to a low-cost quadruped robot, we present a method of improving uneven terrain overcoming ability by mounting IMU and reinforcement learning on embedded board and automatically detecting objects using camera and deep learning. The robot consists of the legs of a quadruped mammal, and each leg has three degrees of freedom. We train complex terrain in simulation environments with designed 3D model and apply it to real robot. Through the application of this research method, it was confirmed that there was no significant difference in walking ability between flat and non-flat terrain, and the behavior of performing person detection in real time under limited experimental conditions was confirmed.

• Journal of Korean Foot and Ankle Society
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• v.7 no.1
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• pp.30-35
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• 2003

Purpose: The purpose of this study was to evaluate the result of open wedge osteotomy at the anterior calcaneus with iliac bone graft (Evans procedure) for symptomatic flexible flatfeet in children. Materials and Methods: A retrospective study was conducted between October 1995 and September 2002. Six cases in 3 patients who had symptomatic flexible flatfeet was included. Follow-up averaged 39.5 months. We evaluated the patients' satisfaction by Mann and Reynolds scorring and compared the radiographic results between preoperative and final radiography. Results: The satisfaction outcomes at the last follow-up were excellent in five and good in one. The mean lateral talo-first metatarsal angle was improved from $-20^{\circ}$ to $-3^{\circ}$. The mean calcaneal inclination angle was improved from $8.5^{\circ}$ to $20.8^{\circ}$. The talo-navicular coverage angle was improved from $47.5^{\circ}$ to $7.5^{\circ}$. In one case, we found the subluxation of calcaneocuboidal jont in postoperative radiography. Conclusion: Open wedge osteotomy at the anterior calcaneus for symptomatic flexible flatfeet in children was considered as one of the effective treatment methods.

• Journal of the Korean Chemical Society
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• v.25 no.2
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• pp.97-102
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• 1981

The conversion of methanol to hydrocarbons has been studied over synthetic ZSM-5 zeolite catalyst having high silica to alumina ratio. The conversion products were olefins, paraffins, cycloparaffins, and aromatics, and the catalyst showed especially high selectivity toward the formation of aromatics. The catalyst showed the shape-selectivity and the size of molecules in the product was limited approximately to the size of 1,3,5-trimethylbenzene. Hydrogen form(HZSM-5) was more active, indicating reactions following the dehydration of methanol seemed to be mainly catalyzed by acid sites. Comparison of the reaction characteristics and acid site distribution of the ZSM-5 catalyst with those of mordenite and faujasite type catalysts suggests that cross-linked pore channel structure and the strong acidity of the ZSM-5 catalyst are primarily responsible for the selective formation of aromatics over this catalyst.

• KSBB Journal
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• v.13 no.1
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• pp.90-95
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• 1998

Experiments on the process development for the concentration of polyunsaturated fatty acid (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil by using acyl chain specificity of Candida cylindracea lipase were performed. Five kinds of oils were hydrolyzed with Candida cylindracea lipase. Among then, Candida cylindracea lipase just had low activity on the PUFAs-rich fish oil. After the hydrolysis of fish oil, free fatty acid was removed and fatty acid components of glyceride mixtures were analyzed. When the hydrolysis was about 70%, the DHA content in the glyceride mixture was about three times more than that in the original fish oil. The EPA and stearidonic acid contents in the glyceride mixtures, however, were similar to that of the original fish oil. In this work, these results showed that the concentration process of PUFAs by using the acyl chain specificity of Candida cylindreacea lipase was effective in producing glycerides that contained a high concentration of PUFAs in good yield.

• Physical Therapy Korea
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• v.2 no.2
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• pp.1-8
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• 1995

이 논문의 주목적은 정상인을 대상으로 각기 다른 3가지의 (체중의 1.5 %, 3.0 %, 9.0 %) 부하를 통해서 자세의 불균형을 유발시켰을 때 나타나는 postural movement patterns을 기술하기 위한 연구이다. 연구대상의 허리중심에 체중부하를 주어 균형이 뒤로 이동하게 하여, surface EMG(표면 근전도)를 통하여 Tibialis anterior(Ta), Gastrocnernius(Gc), Quadriceps femoris(Qc), Hamstring(Ha), Rectus abdominalis(Ab)와 Paraspinalis(Pa) 근육들의 motor recruitment pattern(운동회집형태)를 측정하였다. 그리고 비디오 촬영은 고관절, 슬관절, 족관절의 움직임을 보기 위해 사용하였다. 특히 근전도 (EMG)는 자세반응 검사에 있어 첫 근반응(근수축) 경과시간(FR)과 분절간격간의 (ID)시간을 조사하는데 사용되었다. 이 연구의 결과는 4가지 중요한 사실을 전해주고 있다. 첫 번째로서, 연구대상자에게 체중의 1.5 %의 부하를 적용하였을 때 Ta가 가장 먼저 수축을 시작하였고(FR:$88{\pm}19.4$ ms) 발목과 대퇴사이의 분절 간격간(ID)의 평균은 +9.3 ms였다. 또한 족관절의 변화가 가장 뚜렷하여 Nashner(1985)의 족기전을 뒷받침하고 있다. 둘째로는 연구대상자에게 체중의 3.0 %의 부하를 주었을 때 Qc와 Ab근육이 원위부에서 근위부 순서로 수축하였고, 첫 번째 근육수축시간은 ($82{\pm}39.2$ ms)였다. 그리고 이때 분절간격의 평균은 +8.3ms 이였고 Ta는 거의 반응하지 않았다. 족관절과 슬관절에 비해 고관절의 변화가 가장 현저하게 나타났고, 이 또한 Nashner의 고관절 기전과 같은 현상을 보였다. 셋째로 연구 대상자에게 체중의 9.0 % 부하를 허리에 적용하였을 때 근수축은 근위부에서 원위부 순서를 이루어졌다. 즉 Ab,Qc, Ta, Ps순으로 근수축 되었다. Ab가 처음으로 수축하여 첫 반응(FR)은 $73{\pm}3.2$ ms 이였고 슬관절과 고관절의 변화가 가장 뚜렷하였다. 넷째로 연구 대상자에게 체중의 9.0 %부하를 적용하였을 때, 균형을 잡기 위해 뒷걸음치는 것이 관찰되었고 이때 근수축 순서는 Ta,Ab.Ps,Qc,Hs였다. 이 결과는 Nasher의 결과와 불일치하였다. 이상과 같은 결과에서 연구대상자의 자세운동형태(postural movement patterns)는 각기 다른 부하 정도와 시간에 따라 합성적으로 이루어지는 것으로 보여졌다. 특히, 자세운동형태는 부하의 적용위치와 연구대상자의 최근의 경험에 영향을 받은 것으로 밝혀졌다. 결론적으로 말하면 자세운동형태는 중앙신경계의 제한적(한정적) 명령 시스템에 의해서 움직임(movement)이 발생하기 전에 조직된다는 Nashner의 가설을 뒷받침하였다.

• The Korean Journal of Community Living Science
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• v.16 no.3
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• pp.133-141
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• 2005

본 연구는 연변 지역 조선족 여자 대학생을 대상으로 의복태도에 따른 의복구매동기를 조사함으로써 소비자의 심리적 특성을 밝히는데 그 목적이 있다. 2002년 5월에서 6월 사이에 300부의 설문지가 중국 연변 지역의 여자 대학생에게 배부되어 248부의 설문지가 최종적으로 분석에 사용되었다. 설문지는 5점 척도를 사용하였고, 통계처리는 SAS PC 프로그램을 이용하여 빈도, 요인분석, t-test를 하였다. 연구 결과를 요약하면 다음과 같다. 여자 대학생의 의복태도는 유행성, 유명상표지향성, 심미성, 정숙성의 네 요인으로 분류되었다. 각 요인 별로 요인의 평균값이 높은 집단과 낮은 집단으로 분류하여 의복태도에 따른 의복구매동기를 조사한 결과, 유행성${\cdot}$유명상표지향성${\cdot}$심미성${\cdot}$정숙성 네 요인 모두 각 요인 별로 평균값이 높은 집단과 낮은 두 집단 간에 유의한 차이를 나타내었다. 유행성요인에 높은 평균점수를 갖는 집단은 낮은 집단에 비해 멋진 외모나 새로운 유행을 추구하기 위해 의복을 구입하는 동기가 높았고, 미적요인에 높은 평균점수를 갖는 집단은 낮은 집단에 비해 실용적 이유보다는 사회적 모임이나 기분의 변화를 위하여 의복의 구매동기를 가졌다. 이러한 결과를 통하여 의복태도는 중국조선족소비자의 경우에도 의복구매행동을 예측하는 좋은 변수가 될 수 있으며 시장세분화를 위한 유용한 기준이 될 수 있음을 확인하였다.

• Journal of the Korean Arthroscopy Society
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• v.5 no.2
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• pp.124-130
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• 2001

Purpose : To identify occult intra-articular pathologies in the acute ankle fracture using arthroscopy and to investigate the factors to predict its possibility of occult injuries that could be occurred. Materials and Methods : This prospective study included fifty patients who got operation for the ankle fractures. Ankle arthroscopy was performed to document the type and anatomical location of occult lesion. We investigated the correlation between incidence of occult injuries and specific fracture type. Results : Of fifty ankles, 37 ankles had occult lesion. Twenty five loose bodies including displaced fragments were found and various cartilage lesions were found in 31 ankles. Tibial avulsion fragment by anterior inferior tibiofibular ligament was occurred in 6 cases. There was no correlation between the incidence of occult lesion and various factors including age, sex, injury mechanism and fracture type(p>0.05). Conclusion : The ankle arthroscopy had an effective role for the detection and treatment of occult injuries and it was difficult to predict the occurrence or associated accurately in all of th ankle fractures.

• Journal of Korean Foot and Ankle Society
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• v.18 no.1
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• pp.36-39
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• 2014

Tarsal tunnel syndrome is defined as a compressive neuropathy of the posterior tibial nerve in the tarsal canal. Schwannoma is a benign tumor that arises from the peripheral nerve sheath. It presents as a discrete, often tender, and palpable nodule associated with neurogenic pain or paresthesia when compressed or traumatized. The growth rate is usually slow, and these lesions seldom exceed 2 cm in diameter. In addition, local recurrence occurs less than 5%. We report on a case of tarsal tunnel syndrome caused by a large recurred space-occupying lesion measuring $4.3{\times}2.7{\times}2.7cm^3$.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.1
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• pp.134-139
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• 2006

A energy efficiency of quadruped walking robot has been studied mathematical modeling, dynamic analysis or simulation by consumption energy per period. In this paper, We used the quadruped walking robot Titan-VIII in order to carry out this experiment. The total moving length is about 2[m] , the stride length is 0.1, 0.2. 0.3, and walking period is changed by 1.0, 1.5, 2.0, 2.5 3.0[sec] Per each stride length. So consumption energy of 15 cases are measured. As a result of this experiment we obtained the best energy efficiency when stride length was 0.3[m], and Period was 1.5[sec].

• Journal of the Korean Chemical Society
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• v.28 no.5
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• pp.335-341
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• 1984

Acetals of ${\alpha},{\beta}$-unsaturated aldehydes reacted readily with aryl bromides in the presence of palladium catalyst and triethylamine to form aryl conjugated enals. Acrolein diethyl acetal and methacrolein diethyl acetal were reacted with phenyl bromides with substituents such as methyl and isopropyl groups at $100^{\circ}C$. The reaction products yields except the reaction of o-bromotoluene with methacrolein diethyl acetal. The products were identified by proton nuclear magnetic resonance and infrared spectroscopy. In the reverse combination of reactants to prepare aliphatic 2,4-dienals in good yield of above 50%, 3-bromopropenal dimethyl acetal and (E)-3-bromo-2-methylpropenal diethyl acetal were used as vinylic halide reactants and 1-alkenes and ethyl acrylate as olefin reactants.