• 항공우주시스템공학회지
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• 제15권2호
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• pp.10-15
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• 2021

The propeller wake of tiltrotor-type aircrafts, such as TR-60 and quad tilt propeller (QTP) UAV, in hover substantially impinges the upper surface of the primary wing and generates a downward load. This load is directly proportional to the thrust of the propeller and reduces the available payload. Therefore, wing and nacelle mechanisms should be carefully designed to reduce downward load. This study conducted a numerical analysis of the rotating propeller in hover to predict the downward load of a QTP UAV. An unsteady three-dimensional Navier-Stokes solver was used along with a sliding mesh for the simulation of the rotating propeller. To reduce the downward load, the tilting mechanisms of the partial wing and nacelle were simultaneously introduced and numerically analyzed. Finally, the downward load was predicted by 14% of isolated propeller thrust; further, the downward load could be reduced by adopting the partial wing and nacelle tilting concept.

• 한국기계가공학회지
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• 제7권2호
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• pp.45-51
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• 2008

The objective of this study is to develop an automatic object changer unit to improve processing problems existed in the conventional horizontal machining center. In order to perform this objective, a upward and downward traverse unit in which a unit that consists of a motor and reducer, chain and sprocket wheel, and upper and lower base employed in an automatic object changer unit performs sliding contact motion in a frame was designed. To achieve this design, constraint conditions for the upward and downward traverse unit first designed. Then, an operation mechanism was designed and that was introduced as a sum of kinetic energy for the sprocket wheel and upper and lower base based on the moment of inertia, which is the kinetic energy of the converted upward and downward traverse unit in the side of the reducer. In addition, The work required to rotate the converted upward and downward traverse unit in the side of the reducer by one revolution can be calculated using the sum of work that is required in the sprocket wheel and upper and lower base that is a part of the upward and downward traverse unit. Furthermore, the converted equation of motion in the side of the motor can be introduced using the equation of motion using the converted upward and downward traverse unit in the side of the motor. Then, Then, a proper motor can be determined using predetermined specifications employed in the motor and several parameters in the upward and downward traverse unit in order to verify such predetermined specifications. Also, a design of a horizontal traverse unit that performs sliding motion on a upward and downward traverse unit and simulation that verifies the results of this design are required as a future study.

• 한국사회복지학
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• 제63권2호
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• pp.133-154
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• 2011

본 연구는 자녀와 동거하지 않는 65세 이상 노인을 대상으로 노년기 독립적인 삶의 기대감과 노인의 하향이전의 관계를 실증적으로 검토하여 분석하였다. 분석에 사용된 자료는 "2008년도 전국 노인생활실태 및 복지욕구조사"자료이며, 자료분석은 다중회귀분석을 이용하였다. 분석결과, 노인의 독립적인 삶의 기대감 정도는 노인의 하향이전 정도에 정적(+)인 영향을 주는 것으로 나타났으며, 구체적으로 경제적 신체적 독립적인 삶의 기대감은 노인의 경제적 서비스 하향이전에 정적(+)인 영향을 주는 것으로 나타난 반면, 심리적 독립적인 삶의 기대감은 노인의 서비스 하향이전에는 정적(+)인 영향을 주는 것으로 나타났지만 경제적 하향이전에는 영향을 주지 않는 것으로 나타났다.

• 한국전문물리치료학회지
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• 제19권4호
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• pp.32-37
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• 2012

The purpose of this study was to investigate the quantitative data of downward pulling tension in subjects with scapular downward rotation syndrome (SDRS) before and after 6-week self scapular upward rotation exercise (SURE) program. Eleven subjects with bilateral SDRS. The downward pulling tension(DPT) was measured digital tension-meter. The tension force data were collected using a surface electromyography before and after a 6-week self-scapular SURE program. The significance of difference between pre- and post-program was assessed using a paired t-test, with the level of significance set at ${\alpha}$=.05. The results showed that significant differences between pre- and post-SURE program were found for DPT (p<.05). These findings suggest that 6-week self SURE program is effective for reducing DPT in subjects with SDRS. Additionally, our DPT measurement can be useful for maintaining shoulder position and providing quantitative data between pre- and post-SURE program during passive correction of scapular position test.

• 대한치과교정학회지
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• 제14권1호
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• pp.161-172
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• 1984

This study was undertaken to evaluate the cephalometric changes of the soft tissue and skeletal profile subsequent 10 the rapid palatal expansion in 25 Angle's Class III cases, ranging in age from six to fifteen years, with cross-bite of the anterior teeth, underdevelopment of maxilla and facial disharmony Following results were obtained: 1. ANS moved downward, Point A presented forward & downward movement increasing SNA and Point B presented backward & downward movement decreasing SNB. 2. Mandible was rotated to backward & forward and maxilla moved forward & downward with the bite opening and improvement of anterior teeth cross-bite. 3. Soft tissue on mandible was rotated to backward & forward following hard tissue changes causing the decrease of facial convexity angle and backward & downward rotation of Point B', Pog'. 4. Response of the upper lip was more significant in downward than forward direction, and correlated with the upper central incisor and mandible rotation. 5. Response of the lower lip was more significant in downward than backward direction, and correlated with the mandible rotation. 6. There was a rather high degree of correlation between skeletal profile and soft-tissue profile, 1 : LS, $\bar{1}$:Pog', Pog:LS, Pog:LI, Pog:Pog' in horizontal measurements and $\bar{1}$:Pog', Pog:LI, Pog:Pog' in vertical measurements.

• 대한치과교정학회지
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• 제18권2호
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• pp.367-385
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• 1988

In case of skeletal Class III malocclusion with underdeveloped maxilla, the extraoral orthopedic force for the stimulation of maxillary growth or anterior reposition of the maxilla has been used clinically for the improvement of facial skeletal relationship. The purpose of this investigation was to examine the initial reaction of maxillofacial complex to the maxillary protraction by using extraoral orthopedic force. The dried human skull was used and this investigation was done by means of double exposure holographic interferometry. The protraction forces placed on the canine or the first molar were parallel, $10^{\circ}$ downward, $20^{\circ}$ downward to the occlusal plane. Fringe pattern of each protraction condition was compared and analized. The results were as follows: 1. Each maxillofacial bone displaced saparately. 2. More displacement was shown at the area of the teeth and the alveolar bone. 3. A counterclockwise rotation of the maxilla wa decreased by downward protraction and especially 20 degree downward protraction from the canine showed least rotation. 4. On the zygomatic arch, outward bend was observed and this effect was decreased by downward protraction. 5. On the zygomatic bone, the counter clockwise rotation was increased by the downward protraction. 6. When maxillary expansion was applied at the same time, outward and upward displacement with counterclockwise rotation was observed on the maxilla. 7. The lateral pterygoid plate of sphenoid bone was affected by maxillary protraction.

• 대한물리의학회지
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• 제16권2호
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• pp.1-8
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• 2021

PURPOSE: This study examined the effects of changes in the head direction (forward, upward 10° and downward 10°) on the quadriceps, center of pressure (COP), and foot pressure during squat exercises. The aim was to determine if the head direction could better activate the quadriceps muscle and provide a safer and stable squat posture during squat exercise. METHODS: Fifteen healthy college students were asked to stand on a Zebris, and three electrodes for sEMG were attached to their vastus medialis oblique (VMO), vastus lateralis (VL), and rectus femoris (RF) muscles. The participants then performed squatting exercises under three head directions (forward, upward 10°, and downward 10°). Surface electrodes were then used to record the EMG data during exercise. The Zebris FDM-SX was used to measure the foot pressure and COP of the participants. RESULTS: In squat exercise, the upward head direction group showed significantly higher VL activation than the downward head direction group (p < .05). The upward head direction group showed a significant backward change in the deviation of the COP than the downward and forward groups (p < .05). The upward head direction group showed a significant decrease in forefoot pressure than the downward and forward groups (p < .05) and an increase in the hindfoot pressure compared to the downward and forward groups (p < .05). CONCLUSION: The head direction upward in squat exercise has a positive effect on the quadriceps.

• 치과방사선
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• 제22권2호
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• pp.315-327
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• 1992

The purpose of this study was to evaluate the utilization of the orthopantomograph as a diagnostic aid to observe maxillary sinus and adjacent structures. For achieving this goal. the lead plates were attached to the five walls of the maxillary sinus of a human dry skull. The dry skull was placed in fourteen different positions; standard. 20mm forward. 20mm backward. 10 degree upward. 10 degree downward. 20mm lateral. forward & upward, forward & downward. forward & lateral. backward & upward. backward & downward, backward & lateral. upward & lateral. downward & lateral position. The obtained results were as follows: 1. The image of the medial wall was observed very differently according to the head positions. 2. The image of the anterior wall was observed at medial third to half of the maxillary sinus in each head position. 3. the image of the posterior wall was always observed at lateral third of the maxillary sinus in all head positions and more obviously in the downward-lateral position. 4. The image of the superior wall was observed at the inferior third to half of the orbit in each head position. 5. The image of the inferior wall was always observed at the inferior third of maxillary sinus in all head positions and observed more obviously in the standard and downward-lateral positions. 6. The images of the zygomatic process. zygomatic arch and zygomaticotemporal suture were observed very well in the downward-lateral position.

• Journal of Preventive Medicine and Public Health
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• 제49권1호
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• pp.53-60
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• 2016

Objectives: The purpose of this study is to examine the magnitude of and the factors associated with the downward mobility of first-episode psychiatric patients. Methods: This study used the claims data from the Korean Health Insurance Review and Assessment Service. The study population included 19 293 first-episode psychiatric inpatients diagnosed with alcohol use disorder (International Classification of Diseases, 10th revision [ICD-10] code F10), schizophrenia and related disorders (ICD-10 codes F20-F29), and mood disorders (ICD-10 codes F30-F33) in the first half of 2005. This study included only National Health Insurance beneficiaries in 2005. The dependent variable was the occurrence of downward mobility, which was defined as a health insurance status change from National Health Insurance to Medical Aid. Logistic regression analysis was used to assess factors associated with downward drift of first-episode psychiatric patients. Results: About 10% of the study population who were National Health Insurance beneficiaries in 2005 became Medical Aid recipients in 2007. The logistic regression analysis showed that age, gender, primary diagnosis, type of hospital at first admission, regular use of outpatient clinic, and long-term hospitalization are significant predictors in determining downward drift in newly diagnosed psychiatric patients. Conclusions: This research showed that the downward mobility of psychiatric patients is affected by long-term hospitalization and medical care utilization. The findings suggest that early intensive intervention might reduce long-term hospitalization and the downward mobility of psychiatric patients.

• 보건의료산업학회지
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• 제6권1호
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• pp.117-128
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• 2012

This study purports to investigate the difference between upward and downward feedback and to find out the strategy to enhance the validity and reliability of the multi-source feedback system. Data were collected from 88 middle-level managers working at divisions of nursing, administration, and clinical technology at a university hospital located in north-eastern part of South Korea. Data about multi-source feedback of the year 2008 and 2009 were obtained from the department of personnel management under the permission of hospital top management. The collected data were analyzed using t-test, and correlation analysis. The major findings of the study were as follows: First, the scores of downward feedback were always higher than those of the upward feedback. Second, the scores of downward feedback were always higher than those of the upward feedback in both nursing and administrative staff, while no significant difference was found in technological staff. Third, the upward and downward feedback scores were significantly different in terms of the evaluation factors. Fourth, there were significant correlations between total scores of downward and upward feedback, and evaluation factor scores. In conclusion, the composition and weight of measurement items of multi-source feedback needs to be designed differently in terms of each job characteristics.