• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.337-337
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• 2009

가시광선영역에서 매우 균일한 높은 투과성뿐만 아니라 근적외선영역에서 가파른 홉수성 엣지와 함께 낮은 투과율을 제공하는 산화구리(II)를 함유하는 포스페이트 유리는 컬러 비디오 카메라의 컬러 보정 필터, 발광 컬러 디스플레이용 보호판(sheild), 모노크로메이터의 미광 필터, 플라스틱 복합재 필터의 무기 성분 및 CCD(전하 결합 소자) 및 CMOS(상보성 금속 산화물 반도체) 카메라 및 검출기 분야용 필터 유리로서 사용된다. 용융온도 및 산화구리(II) 첨가량에 따른 투과율을 측정하기 위해 포스페이트 유리 시료를 $1100\sim1500^{\circ}C$ 용융한 후 $400^{\circ}C$에서 2시간 동안 어닐링 공정을 거쳐 제조하였다. 제조된 시료는 두께 0.3mm로 폴리싱하여 자외선-적외선 분광 광도기를 이용하여 광학적 특성을 측정하였다. 본 실험을 통하여 용융온도에 따라 가시광선영역 및 근적외선영역에서의 투과율 거동을 비교한 결과 $1100\sim1200^{\circ}C$에서의 우수한 투과율 특성을 나타냈다. 용융온도가 내려감에 따른 가시광선영역 (400~600nm)에서 높은 투과율 및 근적외선영역 (750~1100nm)에서 낮은 투과율과 가파른 흡수성 엣지를 나타냈다.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1333-1337
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• 1987

본 연구는 머리운동 제어 시스템에 대한 생체 물리학적인 모델링과 시뮬레이션을 통하여 모델의 동특성을 조사하였으며, 생체운동(머리-안구)의 상호 관계를 비교하였다. 결과를 요약하면 다음과 같다. 1) 시스템을 구성하고 있는 매개변수의 변화가 출력에 미치는 영향을 조사하기 위해 감도해석법을 써서 감도계수를 구한 결과, 입력 제어신호의 펄스높이(PH), 동근의 펄스폭(PW1), 길항근의 펄스폭(PW2)이, 시스템의 출력특성을 결정하는 가장 중요한 매개변수 임을 알 수 있었다. 2) 비 선형 제어모델의 선형화를 통하여 선형모델의 응답특성과 크나큰 차이가 없음을 알았다. 3) Main-Sequence도를 작성하여 실험 데이터와 비교한 결과, 거의 일치함으로서 모델의 타당성을 입증하였다. 4) 머리운동이 시간최적으로 응답하기 위해서는 bang-bang 제어법칙이 적용되어야 함을 알았다. 5) 머리운동이 목표점에 도달하는 순간에는 길항근의 역제통 펄스가 가해 짐으로서, 길항근이 궤적의 마지막 부분을 지배함을 알았다. 6) 머리-안구운동의 main-sequence도를 비교 함으로서 상호관계를 규명하였다. 앞으로는 이 모델링 법을 개선확장하면, 비행시 파일럿의 생체 시뮬레이션, 헬멧 조준 사격 시스템등의 항공공학, 생체의용공학 연구 및 제어입력을 생체신호로 하는 로봇틱스 연구에 본 연구 방법은 유용하리라 생각된다.

• Explosives and Blasting
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• v.21 no.1
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• pp.69-76
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• 2003

Test blasting has been performed with V-cut to investigate the characteristics. Blasting vibrations were measured at two directions, the proceed direction and side direction. Propagation characteristics were determined by regression analysis; square root scaled distance and cube root scaled distance with maximum charge per delay of the blast. Testing result, The cross point was 62m in the allowable vibration velocity of 3mm/sec and 46m In 5mm/sec. Also, vibration level with measuring point was highest and decayed fastest, adapting to cube root scaled distance, for the proceed direction on ground.

• Journal of Oral Medicine and Pain
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• v.38 no.2
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• pp.149-159
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• 2013

The purpose of this study was to investigate the relationship between horizontal morphology of lateral pterygoid muscle and onset of temporomandibular joint disorders. Randomly selected 150 subjects, assigned with equal number in terms of gender and age group, were included. The axial and sagittal images in their magnetic resonance images of the temporomandibular joints were used to measure the morphologic characteristics of lateral pterygoid muscles and temporomandibular joints. The measurement variables were maximal horizontal width and insertion angle to the condyle, position of the articular disc, condylar deformity, and joint effusion. In addition, presence or absence of the temporomandibular joint pain was examined through history and palpation of the joints. The relationships among measurement variables were analyzed and the results were as follow. The insertion angle of the lateral pterygoid muscle to the condyle was higher in the joint of anterior disc displacement without reduction than that in the joint of normal disc position. In addition, the maximal horizontal width of the lateral pterygoid muscle was significantly increased in joints with pain than those without pain. Also, the insertion angle was significantly higher in younger age group and the maximal width was significantly greater in male than in female. These results suggest that high insertion angle of lateral pterygoid muscle might be an important anatomic predisposing factor for anterior disc displacement in temporomandibular joint and muscular activity of lateral pterygoid muscle might be affected by preauricular pain. In conclusion, there might be a bi-directional interaction between lateral pterygoid muscle and joint in the progression of anterior disc displacement in temporomandibular joint.

• Journal of dental hygiene science
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• v.10 no.4
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• pp.279-286
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• 2010

To investigate the correlation between the perceived symptom of musculoskeletal diseases and psychosocial factors in dental professionals in Chungcheong province, a self-administered survey was conducted on 206 dental professionals in Chungcheong province from March 9th, 2009 to March 28th, 2009. SPSS WIN 12.0 software was used to analyze the data and the following results were obtained. 1. As for the perceived symptom degree of musculoskeletal diseases based on measured body parts, the frequency of 'high' was the highest in all the parts of the body. 2. As for gender, females showed higher interest in musculoskeletal diseases than males (p=.000). As for age, subjects ranged 26~30 years showed the highest interest in musculoskeletal diseases, which was statistically significant (p=.000). 3. Work satisfaction showed a positive correlation with the perceived symptom of musculoskeletal diseases in lumbar group and lower extremity group. Work stress showed a weak negative correlation with the perceived symptom of musculoskeletal diseases in lumbar group and lower extremity group. Coworker satisfaction showed a positive correlations with the perceived symptom in upper extremity group and lower extremity group. Hospital satisfaction showed a positive correlations with the perceived symptom in upper extremity group, lumbar group and lower extremity group. Working environment satisfaction showed a positive correlations with the perceived symptom in neck group, shoulder group, upper extremity group and lower extremity group. This study showed a correlation between psychosocial factors and the perceived symptom of musculoskeletal diseases based on body parts. Therefore, psychosocial factors should be considered when the prevention and management program of musculoskeletal diseases are developed.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.265-271
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• 2021

This study aimed to define the diagnostic criteria for cervicogenic headache and propose an efficient method of clinical evaluation and physical therapy. Fifteen patients with cervicogenic headache and 15 healthy individuals were recruited and categorized into the test group and the control group, respectively. The groups were compared in terms of muscle characteristics, muscle activity and posture, and the intervariable correlations were analyzed for the test group. A significant between-group difference was found in the stiffness of the suboccipital muscle and the tone and stiffness of the upper trapezius muscle (p<.001). In posture comparison, a significant difference was noted in neck tilt angle and the T1 slope angle (p<.05). The activity of the sternocleidomastoid muscle was also significantly different between the groups (p<.001). When the correlations among the muscle characteristics, the posture, and the activity of the sternocleidomastoid muscle were analyzed for the test group, a positive correlation was found between the tone and the stiffness of the suboccipital muscle (p<.001) and between the tone and the stiffness of the upper trapezius muscle (p<.001). The findings of this study suggest a more efficient approach for the assessment and treatment of cervicogenic headache patients. It is considered that, further studies including more subjects of various job categories and comparing the outcomes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2691-2697
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• 2011

The purpose of the dissertation is to offer basic data available for being conducive to application of a training program by comparatively analyzing the players' physical strength, the knee joint, a hip joint, power of the trunk joint and muscle power in order to study isokinetic strength and muscle power between short distance athletes and Taekwondo players. This study measured peak power, %Body weight peak power, always power, and %Body weight peak power targeting 8 male athletes and 8 male Taekwondo players who warmed up 10 minutes before from the test to reduce repulsion and unfamiliarity at the instrument. The power of the knee joint($60^{\circ}$/sec), muscle power($180^{\circ}$/sec), were measured by using HUNOM(U.S.A). As a result of the physical strength, statistically, short distance athletes were indicated to be better in muscle strength, muscular endurance than Taekwondo players, and there was no significant difference between flexibility, power, and muscular endurance. Although the short distance athletes were indicated to be better in right and left muscle strength of knee joint than Taekwondo player, there was no significant difference and Taekwonde players were indicated to be higher at the right and left muscle power than short distance athletes.

• Korean Journal of Environment and Ecology
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• v.25 no.5
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• pp.717-724
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• 2011

The objectives of this study were to analyze environment in the forest and growth characteristics for investigating the characteristics of Robinia pseudoacacia distribution in a Pinus thunbergii forest at the coast. As a result of analyzing inhibitory factors of Robinia pseudoacacia distribution in a Pinus thunbergii forest at the coast, it is considered that the salt level included in a sea wind is supposed to be the primary factor of the slow growth for Robinia pseudoacacia since brown leaves, wilting and early leaf fall have appeared in the 0m spot from the artificial dune which has the high salt level. However, the soil properties and light environment hardly have a effect on the growth of Robinia pseudoacacia because there is no difference among planting places. Also, the growth ring of the horizontal root in 2year individuals 0.1~0.2m away from the dune have been formed for 1 year only as a consequence of analyzing growth rings of Robinia pseudoacacia growing on the coast. It can be infered that the nourishment of the horizontal root from individuals growing on the coast have been provided for the first 1 year only. It is estimated that, in case of the nearby areas on the coast, it is not enough to provided nourishment to the horizontal root due to obstructing the growth of new individuals by a sea wind, so the growth of the horizontal root would be hampered. Therefore, it is considered that impedient Robinia pseudoacacia distribution in a Pinus thunbergii forest at the coast is caused by making no growth of new horizontal roots and newborn individuals.

• Journal of dental hygiene science
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• v.9 no.5
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• pp.531-538
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• 2009

This study examined the musculoskeletal symptom experience rate of some dental clinic workers and the factors influencing musculoskeletal symptoms according to their working environment and health habit. To that end, between March 9 and March 28, 2009, 200 workers at dental clinics in Chungcheong-do were surveyed using the self-administered questionnaire method. The data were analyzed using the SPSS WIN 12.0 program. The following conclusion was reached. 1. One-year musculoskeletal symptom experience rates of the subjects were categorized according to pans of the body: shoulders - 60.5%, lower limbs (legs, knees, and feet) - 57.0%, the lumbar region (back and waist) - 56.0%, the neck - 51.0% and the upper limbs (arms, wrists, and fingers) - 32.0%. 2. In general characteristics, a statistically significant difference was found according to gender, age, education, position, and oral health state. In working environments, a statistically significant difference was found according to work experience, the average daily number of patients handled, the average daily working hours, the posture for diagnosis, and satisfaction over work. In health habit, a statistically significant difference was found according to regular exercise, regular examination, and regular eating habit. 3. Factors influencing musculoskeletal symptoms were examined. As a result, influencing the musculoskeletal symptom experience were satisfaction over work among working environment characteristics, and regular exercise among health habit characteristics.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.947-953
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• 2005

Previous test results showed that the current ASTM(American Standard for Testing and Materials) grip adapter for GFRP(Glass Fiber Reinforced Polymer) rebar was not fully successful in developing the design tensile strength of GFRP rebars with reasonable accuracy. It is because the current ASTM grip adapter which is composed of a pair of rectangular metal blocks of which inner faces are grooved along the longitudinal direction does not take into account the various geometric characteristics of GFRP rebar such as surface treatment, shape of bar cross section as well as physical characteristics such as poisson effect, elastic modulus in the transverse direction and so on. The objective of this paper is to provide how to proportion the optimum diameter of inner groove in ASTM grip adapter to develop design tensile strength of GFRP rebar. The proportioning of inner groove in ASTM grip adapter is based on the force equilibrium of GFRP rebar between tensile capacity and minimum frictional resistance required along the grip adapter. The frictional resistance of grip adapter is calculated based on the compressive strain compatibility in radial direction induced by the difference between diameter of GFRP rebar and inner groove In ASTM grip. All testing procedures were made according to the CSA S806-02 recommendations. From the preliminary test results on round-type GFRP rebars, it was found that maximum tensile loads acquired under the same testing conditions is highly affected by the diameter of inner groove in ASTM grip adapter. The grip adapter with specific dimension proportioned by proposed method recorded the highest tensile strength among them.