• 대한치과교정학회지
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• 제27권1호
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• pp.119-127
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• 1997

안모의 수직적 부조화에 부합되는 하악이부 형태에 관하여 보고되어 왔다. 이연구는 하악이부의 형태적 변이와 두개안면골격의 수직적 변이사이에 상관성을 관찰하기 위하여 시행되었다. 성인 남녀 부정 교합자 212명의 측모두부 방사선사진에서 이부의 후경과 고경을 계측하고 이부비를 산출한 후, 이부비 평균 -1 표준편차에 포함되는 즉모군(low symphysis군)과 이부비 평균 +1 표준편차에 포함되는 측모군(high symphysis군)으로 분류하고, 이들의 측모두부방사선사진을 계측하고 비교 분석하여 다음의 결론을 얻었다. 1. 이부비가 크면 hyperdivergent face 이고, 이부비가 작으면 hypodivergent face 가 되는 경향을 보였다. 2. 이부비가 크면 하악각도 컷으며, 이들사이의 상관성은 높았다. 3. 이부비와 수직안면 고경사이에 중등도의 상관성이 있었으며, 특히 이부 후경과 전안면고경사이 및 이부 고경과 후 안면 고경사이에도 중등도의 상관성이 있었다. 4. 이부의 형태적 변이와 설골의 위치사이에는 상관성이 없었다.

• 대한물리치료과학회지
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• 제24권1호
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• pp.69-78
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• 2017

Background: The purpose of the present study is to report the effect of muscle performance on knee flexion and extension by chin in exercise. Methods: This study was Participated in 10 healthy subjects. For conducting the chin-in exercise, subjects are lay down with supine position. Using the rounded towel, subjects was performed contraction of longus colli and longus capatis muscle by push the towel. Chin-in exercise was conducted 3 times a day, 4 times a week for 4 weeks. By using the Biodex system4, We measured absolute muscle strength, relative muscle strength, total exercise quantity and average rate of production in knee flexion and extension. The data was analyzed by the repeated-measure ANOVA for comparing before, after exercise 2 weeks, after exercise 4 weeks changes of factors. Results: After chin-in exercise, there was significant difference of before, after 2 weeks and 4weeks results in absolute muscle strength, relative muscle strength, total exercise quantity, average rate of production, agonist/antagonist ratio(p<.05). Conclusion: As a results of this study, chin-in exercise may help to improve muscle ability of knee joint activation and knee joint action performance.

• 대한치과교정학회지
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• 제43권4호
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• pp.168-177
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• 2013

Objective: In this study, we aimed to examine the relationship between chin deviation and the positional and morphological features of the mandible and to determine the factors that contributed to chin deviation in individuals with a unilateral cleft lip and palate (UCLP). Methods: Cone-beam computed tomography (CBCT) images of 28 adults with UCLP were analyzed in this study. Segmented three-dimensional temporomandibular fossa and mandible images were reconstructed, and angular, linear, and volumetric parameters were measured. Results: For all 28 individuals, the chin was found to deviate to the cleft side by 1.59 mm. Moreover, among these 28 individuals, only 7 showed distinct (more than 4 mm) chin deviation, which was toward the cleft side. Compared to the non-cleft side, the mandibular body length, frontal ramal inclination, and vertical position of the condyle were lower and inclination of the temporomandibular fossa was steeper on the cleft side. Furthermore, the differences in inclination of the temporomandibular fossa, mandibular body length, ramus length, and condylar volume ratio (non-deviated/deviated) were positively correlated with chin deviation. Conclusions: UCLP individuals show mild chin deviation to the cleft side. Statistical differences were noted in the parameters that represented positional and morphological asymmetries of the mandible and temporomandibular fossa; however, these differences were too small to indicate clinical significance.

• 한국환경과학회지
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• 제5권4호
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• pp.525-533
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• 1996

Chemical characteristics of the industrial wastewater sludge, degradation of the sludge in soil and CO2 generation and changes of nitrogen in soil treated with the sludge were investigated. The results obtained were summarized as follows: 1. Degradation rate of the sludge in soil was 26% at natural temperature, and 33% at incubation temperature at 12 weeks after treatment. 2. T-C, T-N and the C/N ratio of sludge in soil was 16.0%, 0.63% and 26, respectively, at natural temperature, and 15.0%, 0, 65% and 23, respectively, at incubation temperature at 12 weeks after treatment. 3, Camulative CO2 generation in soil treated with l%, 3% and 5% of sludge was 284, 440 and 512 mg/100 g, respectively, at natural temperature, and 440, 558 g and 654 mg/100g, respectively, at incubation temperature at 12 weeks after treatment. 4, Changes of :norganic nitrogen in soil treated with l%, 3% and 5% of sludge were 7.8, 12.8 and 16.3 mg/100g, respectively, at incubation temperature at 12 weeks after treatment. Mineralization ratio of organic nitrogen in soil treated with 1%, 3% and 5% of sludge was 10.7%, 13.6% and 15.2%, respectively, at incubation temperature at 12 weeks after treatment. 5. Chanties of pH in soil treated with 1%, 3% and 5% of Industrial wastewater sludge were in the range of 6.7~7, 5 at natural temperature, and 6.1~7.9 at incubation temperature at 12 weeks after treatment.

• 한국전문물리치료학회지
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• 제26권4호
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• pp.1-9
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• 2019

Background: Cervical dysfunction is a common pathomechanical marker in individuals with forward head posture (FHP). To overcome the limitations of the isometric chin-tuck (ICT) exercise, dynamic neuromuscular stabilization (DNS), which emphasizes an entire spinal chain exercise, has recently shown promising clinical results. Objects: Purpose of this study was to compare the immediate effects between ICT and DNS techniques. Methods: 43 young subjects (mean age, $24.0{\pm}5.0$ years) were recruited. Group of subjects with FHP were measured under baseline, ICT, and DNS conditions. Outcome measures included sitting height, longus colli (LC) and sternocleidomastoid (SCM) muscle thickness and LC/SCM thickness ratio. One-way repeated measures ANOVA was used to compare the continuous dependent variables among FHP, ICT, and DNS conditions at p<.016. Results: Both ICT and DNS exercise conditions yielded significantly increased LC muscle thickness, LC/SCM thickness ratio and sitting height than did FHP condition (p<.0001, respectively). Sitting height was significantly greater in DNS exercise than in the ICT exercise (p<.0001). Conclusion: The present results demonstrated that sitting height was greater in the DNS exercise than in the ICT exercise, as well as both corrective postural training exercises were effective on LC/SCM muscle balance ratio when compared with the baseline FHP condition. Therefore, it is considered that DNS exercise can be the recommended exercise for people with FHP.

• 경영과학
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• 제24권2호
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• pp.33-42
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• 2007

In this paper we consider an alternate m machine scheduling problem in which each job having at most two eligible machines should be assigned with the objective of makespan minimization. For this problem. we propose a $O(m2^m)$ time rounding algorithm with performance ratio at most 1.5. For a little general problem where each job can be processed in at most three machines, we prove that a polynomial time algorithm does not exist with performance ratio less than 1.5.

• 대한치과교정학회지
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• 제34권5호
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• pp.408-416
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• 2004

일반인들이 선호하는 상순과 턱의 수직 비율(Sn-Stm/Stm-Me')을 알아보기 위해 남녀 각 2명의 연조직 측모(Profile)를 상순과 턱의 수직비율에 따라 상악의 변화없이 하악만을 변화시켜 1/1.8, 1/1 9, 1/2.0, 1/2, 11/2.2 비율의 5개의 측모 사진을 만들어 치과의사 44명(남자 22명 여자 22명)과 일반인 430명(남자 303명, 여자 127명)을 대상으로 하여 설문조사를 통하여 선호도를 조사하여 다음과 같은 결과를 얻었다. 대상의 가장 선호하는 안모에 대한 성별간의 선호도 차이는 통계적으로 유의하지 많았다. 대상의 가장 선호하는 안모에 대한 치과의사와 일반인 집단간의 선호도 차이는 통계적으로 유의하지 않았다. 남녀 측모 모두에서 가장 선호하는 측모의 상순과 턱의 비율은 1/1.9이었으며 가장 선호하지 않는 비율은 1/2.2로 나타났다. 이상의 결과를 종합하여 볼 때, 이전의 연구에 비해 상순과 턱의 수직비율에서 턱의 비율이 다소 작은 측모, 즉 상순과 턱의 수직 비율이 1/1.9인 안모를 가장 선호하는 것으로 나타났다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2430-2434
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• 2011

Dynamic response is an important consideration because of the possibility of resonance according to KTX running over a railway bridges. When KTX runs over the bridge at critical speed, dynamic response is very depending on damping ratio. Current damping ratio for design of high-speed railway bridges adopted EUROCODE without verification of domestic railway bridges. The purpose of this study is to obtain the coherent damping ratio of high-speed railway bridges. Free vibration signal after KTX runs over a high-speed railway bridge was applied. The representative value from distribution of damping ratio was considered.

• 미생물학회지
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• 제2권1호
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• pp.12-16
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• 1964

Lee, Yung Nok and Chin, Pyung (Dept. of Biology, Korea University, Seoul, Korea) : Action of ascorbic acid indoleacetic acid on the oxidation of succinate and coupled phosphorylation in Chlorella mitochondria. Kor. Jour. Microbiol., Vol.2, No.1, p12-16 (1964) Mitochondria were isolated from Chlorella ellipsoidea and the action of ascorbic acid and indoleacetic acid on the succinate oxidation and coupled phosphorylation in mitochondria suspension were examined. Oxidation of succinate used as substrate, and phosphorylation coupled to oxidation were strikingly enhanced by the addition of ascorbic acid, while in case of indoleacetic acid it were a little. In a view of phosphorylative efficiency, P/O ratio resulting from the addition of ascorbic acid was decreased and it may be considered as the result of a partial oxidation of ascorbate in mitochondria.

• Wind and Structures
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• 제17권5호
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• pp.537-552
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• 2013

Wind tunnel experiments were performed to study the wind loads on an inclined flat plate with and without a guide plate. Highly turbulent flow, which corresponded to free-stream turbulence intensity on the flat roof of low-rise buildings, was produced by a turbulence generation grid at the inlet of the test section. The test model could represent a typical solar collector panel of a solar water heater. There are up-stream movements of the separation bubble and side-edge vortices, more intense fluctuating pressure and a higher bending moment in the turbulent flow. A guide plate would result in higher lift coefficient, particularly with an increased projected area ratio of a guide plate to an inclined flat plate. The value of lift coefficient is considerably lower with increased free-stream turbulent intensity.