• 대한소아치과학회지
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• 제37권2호
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• pp.193-201
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• 2010

유아기 우식증은 유아와 어린이에 생긴 우유병 우식증 및 다발성 우식증을 포함한 좀 더 포괄적인 명칭으로, 이전 연구들에서 유아기 우식증이 어린이의 신체 성장에 영향을 미친다고 보고된 바 있다. 이번 연구의 목적은 유아기 우식증이 어린이의 신체 성장에 미치는 영향을 연령대 별 및 우식 이환 정도에 따라 평가하는 것으로, 신체 성장 평가 지표로 신장과 체중을 사용 하였다. 연세대학교 치과대학병원 소아치과에 내원한 환자를 유아기 우식증에 이완된 실험군과 이완되지 않은 대조군으로 나누어 평가하였다. 환자의 연령을 12개월 단위로 나누고, 각 연령대 별로 유아기 우식증이 어린이 신장과 체중에 미치는 영향을 평가하였다. 대조군과 실험군의 연령별 성장 백분위 분포도를 비교하기 위해 2007년 대한민국 질병관리본부에서 공포한 표준성장도표를 사용하였다. 대조군과 실험군 간의 표준 신장 및 체중을 비교하기 위해 two-sample T test를 사용하였고, 두 그룹 간의 성장 백분위 분포도를 비교하기 위해 Likelihood Ratio Chi-square test를 사용하였다. 대조군과 ECC군 사이의 평균 신장 및 체중의 차이를 비교해본 결과 남자와 여자 어린이에서 공통적으로 나타나는 경향으로 통계학적 유의성이 항상 있진 않았으나 만 3-4세를 기준으로 연령이 어릴수록 ECC군의 평균 신장 및 체중이 대조군에 비해 증가하며, 그 이후에는 ECC군의 평균 신장 및 체중이 오히려 대조군에 비해 감소하는 경향을 관찰할 수 있었다. 이러한 경향은 남자 어린이의 평균 체중을 제외한 다른 모든 경우에서 공통적으로 나타났다. 평균 신장과 체중의 유의할만한 차이를 가진 만 3-4세 이상의 군에서 성장 부전으로 정의되는 3 percentile 이하가 차지한 비율은 대조군에 비해 ECC군에서 더 높았다. 이상의 결과를 토대로 유아기 우식증이 어린이의 신체 성장에 부정적인 영향을 미칠 수 있으며, 연령에 따라 유아기 우식증에 의한 영향이 다른 형태로 나타남을 추측할 수 있었다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.827-834
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• 2000

A granular herbicide applicator attached to conventional ride-on rice transplanter with 6 rows was developed in order to carry out both transplanting and herbicide application at once. It resulted in labor saving by 98%. The prototype is composed of a metering device and a spinning disc spreader. The application rate per 10a can be varied from 1 to 3 kg and the application swath is 1.8 m, which is the planting width of the ride-on rice transplanter with 6 rows. The angular speed of spinning disc and the application height were used as design factors to obtain the uniform distribution of herbicide granules. As the result of experiment, the distribution uniformity showed a tendency to be proportional to the increases of both spinner angular speed and application height. The prototype with angular speed of spinning disc of 7359 rpm and the application height of 20 cm was made and its distribution uniformity was relatively uniform with the CV(coefficient of variation) of 21.7%. In field test, when the tested herbicides such as ACl40+Stomp and Londax+YRC were applied, the weed control has continued for 65 days since transplanting was done.

• 한국공작기계학회논문집
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• 제16권2호
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• pp.100-105
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• 2007

Electro-rheological(ER) fluid and valve are fabricated and evaluated experimentally in its durability to utilize the hydraulic control systems for long term operation. The two-ports ER valve used in the experiment consist of twelve parallel multi-layer electrodes and provide a restriction to the passage of ER fluid because of the viscous pressure drop and a component induced by the electric field. The durability test of ER valve are performed by measuring the surface roughness of electrodes with variation of an electric field strength and test time(1000 or 1800min.). Also, the shear stress and shear rate are measured to evaluate the durability of ER fluid as function of time. After durability test, ER shear stress increases approximately proportional to the shear rate with applied electric field intensity, In the ER valve, the center line average height roughness(Ra) of copper electrode increases about 1.56 times and ten-point median height roughness(Rz) increases about 2.2 times after the durability test. An understanding of these durability is essential to predicting the service life of ER fluid and valves.

• Wind and Structures
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• 제26권5호
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• pp.317-329
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• 2018

Wake characteristics of the flow over a finite square prism at different incidence angles were experimentally investigated using an open-loop wind tunnel. A finite square prism with a width D = 15 mm and a height H = 7D was vertically mounted on a horizontal flat plate. The Reynolds number was varied from $6.5{\times}10^3$ to $28.5{\times}10^3$ and the incidence angle ${\alpha}$ was changed from $0^{\circ}$ to $45^{\circ}$. The ratio of boundary layer thickness to the prism height was about ${\delta}/H=7%$. The time-averaged velocity, turbulence intensity and the vortex shedding frequency were obtained through a single-component hotwire probe. Power spectrum of the streamwise velocity fluctuations revealed that the tip and base vortices shed at the same frequency as that ofspanwise vortices. Furthermore, the results showed that the critical incidence angle corresponding to the maximum Strouhal number and minimum wake width occurs at ${\alpha}_{cr}=15^{\circ}$ which is equal to that reported for an infinite prism. There is a reduction in the size of the wake region along the height of the prism when moving away from the ground plane towards the free end.

• 복식
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• 제53권1호
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• pp.117-128
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• 2003

For the advance of Korea's ready-made clothes industry into China, we need some information about the body types of the Chinese and the sizes of ready-made clothes. The purpose of this study is to prepare basic data about the reality and process of the size establishment of clothing sizes in China. The conclusions are as follows. 1. Clothing size establishment was made three times in 1981, 1991, and 1997. At present, the version of 'GB/T 1335-1997 Size' is used. 2. 'GB/T 1335-1997 Size' is composed as follows. \circled1 Based on the drop values of chest girth and waist girth, 4 (Y. A, B, C) body types of adult men and women were chosen. \circled2 Sizes contains Ho and Hyoung, 'Ho' refer to height (cm) and serve as the standard of length, while 'Hyoung' indicate chest girth (cm) and act as the standard of girth. \circled3 The size divisions of the 3 basic items for adults are 5cm (height), 4cm (chest girth), and 2cm (waist girth). So they are named '5ㆍ4, 5ㆍ2 size series', \circled4 For grading in dress production, approximate values to the means of the 2 basic items are called 'center types'.\circled5 Other necessary items for clothing design besides 3 basic items are named 'control items'. \circled6 For babies, children, and adolescents, no body type classification is established. Instead, size series are established according to body height.

• 한국자동차공학회논문집
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• 제9권4호
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• pp.176-183
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• 2001

It is difficult to find out the kinematic characteristics of a vehicle suspension without the usage of CAE software. The application of CAE software into suspension kinematics and dynamics yields the more precise knowledge on the chassis design. In this study, the influence of the suspension geometry on the handling performances of a large-sized bus is investigated using the DADS software. The front and rear suspension of a large-sized bus are a rigid axle suspension with the four control links. The elastokinematic analysis is performed to evaluate the roll characteristics of the front and rear suspension. The elastokinematic responses are evaluated in terms of the roll center height and roll steer for various geometric parameters. The roll center height is mainly dependent on the vertical displacement of a panhard rod and the vertical displacements of lower control links affect the roll steer of a rear suspension. The parameter study with the change of rear suspension geometry is conducted to investigate the vehicle handling performances. This parameter study shows that the vertical displacement and orientation of a panhard rod influence the handling performances of a large-sized bus significantly.

• 제어로봇시스템학회논문지
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• 제18권3호
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• pp.193-200
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• 2012

Mobility is one of the most important issues for search and rescue robots. To increase mobility for small size robot we have focused on the mechanism and algorithm inspired from centipede. In spite of small size, using many legs and flexible long body, centipede can overcome high obstacles and move in rough terrains stably. This research focused on those points and imitated their legs and body that are good for obstacle negotiation. Based on similarity of a centipede's legs and tracks, serially connected tracks are used for climbing obstacles higher than the robot's height. And a centipede perceives environments using antennae on its head instead of eyes. Inspired from that, 3 IR sensors are attached on the front, top and bottom of the first module to imitate the antenna. Using the information gotten from the sensors, the robot decides next behavior automatically. In experiments, the robot can climb up to 45 cm height vertical wall and it is 600 % of the robot's height and 58 % of the robot's length.

• Journal of Forest and Environmental Science
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• 제35권1호
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• pp.25-30
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• 2019

The composition of artificial soil in a containerized seedling production plays an important role in seedling quality as well as environmental issues. We investigated the effects of different types of biomaterials and mixed ratio with artificial soil on the growth of Fraxinus rhynchophylla seedlings. Soil medium was supplemented with 3 levels (0%, 10%, 20%) of pine bark, mushroom sawdust and rice husk. Root collar diameter (RCD), height growth, and biomass have significantly increased when rice husk was applied. Compared with the control, RCD and height growth showed highest in 20% rice husk treatment with an increase of 5.7% and 17.6%, respectively. In contrast, the treatments of pine bark and mushroom sawdust showed lower results in growth parameters (RCD, height growth, and total biomass) than control. Seedling quality index was also highest at the 20% rice husk treatment, but there was not statistically different among treatments. Our results suggested rice husk can be substituted up to 20% of substrates for containerized F. rhynchophylla seedling production system.

• 대한통합의학회지
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• 제3권2호
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• pp.17-28
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• 2015

Purpose: The purpose of this study was intended to investigate the effect on the body composition of the dormitory-type middle school students by implementing the complexed exercise program. Method: As subjects of the study, the dormitory-type middle school students in Chungbuk, divided into 2 grade experimental group(N=46), 3 grade control group(N=49). Group-specific arbitration method, was applied to complexed exercise program (experimental group) and running group (control group). Each training courses 30 minutes 5times weekly, examined the changes in body composition to examine a total of 6-week course effectively. Result: The results were compared with change of Height, Muscle mass, Fat mass, Lean body mass and BMI. Experimental group were significant(p<.05) compared to the control group. Height, Weight, Muscle mass, Fat mass, and BMI of control group wasn't significant(p>.05). Also there were significant difference(p<.05) between groups on Height, Muscle mass, Fat mass and Lean body mass post-test measure. Conclusion: Looking in total from the above results, it is suggested that it is possible to complexed exercise program 6 weeks improves body composition of the dormitory-type middle school students. Therefore, it is possible that the application of complexed exercise program is to effective in improvement of body composition of the dormitory-type middle school students.

• 한국전문물리치료학회지
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• 제15권3호
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• pp.35-43
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• 2008

The purpose of this study was to compare spatio-temporal parameters during walking between patients with idiopathic Parkinson's disease and a control group matched for age, height, and weight. Thirty-three subjects were included in this study. Fifteen normal subjects (age, $63.3{\pm}5.8$ yrs; height, $164.1{\pm}8.7$ cm; weight, $60.7{\pm}17.5$ kg) and eighteen patients (age, $64.0{\pm}7.7$ yrs; height, $164.7{\pm}7.3$ cm; weight, $63.6{\pm}7.7$ kg) participated in the study. The Vicon 512 Motion analysis system was used for gait analysis in each group during walking, with and without an obstacle. The measured spatio-temporal parameters were cadence, walking speed, stride time, step time, single limb support time, double limb support time, stride length, and step length. Results in stride length and step length, when walking without an obstacle, showed a significantly greater decrease in the patient group compared to the control group. During walking with an obstacle, the patient group showed a significantly greater decrease in the step length as compared to the control group. For the control group, there were significant decreases in parameters of cadence and walking speed and increases in parameters of stride time, step time, and single limb support time when walking with an obstacle. The patient group had lower cadence and walking speed and higher stride time, step time, and single limb support time during walking with an obstacle than in walking without an obstacle. These results suggest that patients with Parkinson's disease who walk over an obstacle can decrease cadence, stride length, and step length. Further study is needed, performed with more obstacles and combined with other external cues, such as visual or acoustic guides.