• 응용통계연구
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• 제31권1호
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• pp.123-137
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• 2018

비선형 혼합효과 모형은 다양한 분야에서 반복 측정 자료를 분석할 때 주로 사용된다. 비선형 혼합효과 모형은 개체 내 변동(intra-individual variation)에 대해 고려하는 제 1단계 개별수준모델(individual-level model)과 개체간 변동(inter-individual variation)에 대해 고려하는 제 2단계 개체군모델(population model)의 두 단계로 구성되어 있다. 비선형 혼합효과 모형의 첫 번째 단계인 개별수준모델은 비선형 회귀모형의 모수를 추정하는 것으로 일반적인 비선형 회귀모형과 같고, 주로 보통최소제곱추정 방법을 사용하여 모수를 추정한다. 그러나 최소제곱추정방법은 가정된 비선형 함수가 자료에 의해 명시적으로 드러나지 않는 경우 모수의 추정값과 그 표준오차가 극단적으로 커지는 문제가 발생할 수 있다. 본 논문에서는 최근에 비선형 회귀모형에서 제안된 능형회귀(ridge regression) 방법을 비선형 혼합효과 모형의 제 1단계 개별수준모델에 도입함으로써 이러한 문제를 해결할 수 있는 새로운 추정방법을 제안하였다. 제안된 추정량은 모의실험 연구를 통하여 기존의 표준적인 추정량과 그 성능을 비교하였다. 또한 미국의 National Toxicology Program으로부터 얻어진 정량적 대량고속 스크리닝(quantitative high throughput screening) 실제 자료를 사용하여 추정 방법들을 비교하였다.

• Current Optics and Photonics
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• 제1권3호
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• pp.186-195
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• 2017

Obtaining accurate visibility measurements is a common atmospheric optical problem, and of vital significance to civil aviation. To effectively evaluate and improve the accuracy of visibility measurements, an outdoor atmospheric simulation chamber with dimensions of $1.8{\times}1.6{\times}55.7m^3$ was constructed. The simulation chamber could provide a relatively homogeneous haze environment, in which the visibility varied from 10 km to 0.2 km over 5 hours. A baseline-changing visibility measurement system was constructed in the chamber. A mobile platform (receiver) was moved from 5 m to 45 m, stopping every 5 m, to measure and record the transmittance. The total least-squares method was used to fit the extinction coefficient. During the experiment conducted in the chamber, the unit weight variance was as low as $1.33{\times}10^{-4}$ under high-visibility conditions, and the coefficient of determination ($R^2$) was as high as 0.99 under low-visibility conditions, indicating high stability and accuracy of the system used to measure the extinction coefficients and strong consistency between repeated measurements. A Grimm portable aerosol spectrometer (PAS) was used to record the aerosol distribution, and then Mie theory was used to calculate the extinction coefficients. The theoretical results were found to be consistent with the measurements and exhibited a positive correlation, although they were higher than the measured values.

• 한국전문물리치료학회지
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• 제7권2호
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• pp.76-87
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• 2000

Delayed onset muscle soreness (DOMS) is a common problem that can interfere with rehabilitation as well as activities of daily living. The purpose of this study was to determine the effects of both transcutaneous electrical nerve stimulation (TENS) and microcurrent electrical neuromuscular stimulation (MENS) on DOMS, Twenty-seven untrained and male volunteer subjects were randomly assigned to one of three treatment groups: 1) a group that received TENS (7 Hz), 2) MENS (60 ${\mu}A$, .3 pps) or 3) a control group that received no treatment. Subjects performed repeated eccentric exercise of the non-dominant forearm flexor muscle with submaximal intensity by the simply designed eccentric exercise devices. Treatments were applied after 24 hours and 48 hours. Subjects attended on two consecutive days for treatment and measurement of elbow flexion, extension, resting angle (universal goniometer), and pain (visual analogue scale: VAS) on a daily basis. Measurements were taken after treatment. Analysis of results were as follows; 1) There were no significant differences between TENS and MENS by one-way repeated ANOVA, 2) The t-test for pain, resting, flexion and extension angle revealed significant differences within TENS group, 3) The t-test for resting angle revealed significant differences within MENS group.

• Neonatal Medicine
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• 제16권2호
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• pp.234-238
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• 2009

출혈 후 수두증은 미숙아에서 발생하는 주요한 합병증 중 하나이다. 저자들은 출혈 후 수두증을 가진 초극소 저출생체중아에게 Ommaya reservoir를 삽입하여 2개월 이상 반복적인 뇌척수액 배액을 시행하였다. Ommaya reservoir는 출혈 후 수두증을 가진 초극소 저출생체중아에서 뇌실복강지름술이 가능한 시기까지 수두증 관리에 유용한 방법으로 생각된다. 같은 환아에서 치료 중 뇌척수액 배액에 동반된 저나트륨혈증이 발견되어 나트륨 투여로 치료하였던 1례를 보고한다. 되풀이되는 뇌척수액 배액이 필요한 영아에서 정기적 혈중 나트륨농도 측정이 필요할 것으로 생각된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.264-269
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• 2008

This paper presents the summary of control of abnormal vibration found in the COP motors of a nuclear power plant. All six identical units of COP pump-motor assemblies showed unstable vibration pattern of which one or two showed higher vibration enough to exceed the allowable level from the installation stage. Many trials of test, measurement, overhaul and replacement had been repeated to investigate and solve the problem but only to reach unsatisfactory settlement. Recently several times of site tests are made and followed by significant diagnostic actions in which the authors group participated. It was found that the coupled shafting system of motor and pump is in close resonance with the $1^{st}$ shaft rotating speed. Redesign of topside motor bearing clearance is made to increase bearing stiffness and hence to avoid the resonance which consequently led to reduce the troubled vibration to allowable and stable status.

• 복식
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• 제22권
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• pp.345-356
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• 1994

The Shirts Blouse was produced through the process of shirts Blouse pattern making by utilizing CAD System developed by PAD Sys-tem Techologies Co. Ltd that is suitable to educational use or industrial use. The purpose of this study was to provide the basic data for the development of efficient and various design patterns by applying this pro-cess to the actual business of apparel making. The results were as follows: 1. The applicable range of CAD system 1) The repeated work can be avoided by thansforming and developing the basic pattern stored and the storage and remodification were easy. 2) The deletion duplication movement and copy of all points and lines in the pattern can be made freely and measurement of all lengths and angles the attachment of two patterns were possible. 3) The grading Library of the basic pattern was applied as it was and the time was curtailed by adding only several grading points with the change of design. 2. The problem in the use of the CAD System 1) Through the input of basic pattern by the digitizer the minute size difference was generated as each point on the curve came to be designated. 3) In grading the line of neck girth there was inconveniences to go to the plan view in order find out deviation.

• 한국산학기술학회논문지
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• 제21권6호
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• pp.340-348
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• 2020

본 연구의 목적은 드림스타트 사업에 참여한 저소득층 가정 양육자의 양육스트레스와 아동의 문제행동 간의 상호 인과적 관계를 확인하는 것이다. 연구 대상은 드림스타트 사업에 참여한 아동과 양육자이며, 2015년에 초등학교 1학년인 아동과 양육자를 3년 간 추적 조사하여 2017년까지 참여한 대상자의 자료를 반복 측정 하였다. 연구 방법은 양육자의 양육스트레스와 아동의 문제행동 간의 종단적 발달에 적용하는 아동 효과 및 양육자 효과를 검증하기 위해 자귀회귀교차지연효과모형을 적용하였다. 연구 결과 양육자의 양육스트레스와 아동의 문제행동의 자기회귀 계수가 모두 유의미하여 3년에 걸친 연구기간 동안 높은 수준의 안정성이 있는 것으로 나타났다. 이는 시간의 흐름에 따라 양육스트레스는 비슷한 수준을 유지하고 있음을 의미한다. 또한 양육자의 양육스트레스와 아동의 문제행동 간 인과관계의 원인은 주로 양육자 효과로 설명 되었다. 즉 양육자의 양육스트레스로 인해 아동의 문제행동이 나타나는 것이다. 위의 결과들을 통해 저소득층 가정은 경제적 압박감으로 인해 양육자의 양육스트레스가 가중되고 누적되어 자녀와의 부정적인 상호작용으로 이어져 결국 아동의 문제행동으로 이어질 수 있음을 확인하였다. 저소득층 가정의 누적된 양육스트레스를 경감하기 위해 다양한 양육자의 심리적 지원 방안이 강화되어야 함을 제언하였다.

• 대한치과보철학회지
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• 제43권4호
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• pp.528-543
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• 2005

Statement of problem: Repeated delivery and removal of abutment cause some changes such as wear, scratch or defect of hexagonal structure. It may increase the value of rotational freedom(RF) between hexagonal structures. Purpose: The purpose of this study was to evaluate surface changes and rotational freedom between the external hexagon of the implant fixture and internal hexagon of abutment after repeated delivery and removal under SEM and toolmaker's microscope. Materials and methods: Implant systems used for this study were 3i and Avana. Seven pail's of implant fixture, abutment and abutment screws for each system were selected and all fixtures were perpendicularly mounted in liquid unsaturated polyesther with dental surveyor. Each one was embedded beneath the platform of fixture. Surfaces of hexagonal structure before repeated closing and opening of abutment were observed using SEM and rotational freedom was measured by using toolmaker's microscope. Each abutment was secured to the implant future by each abutment screw with recommended torque value using a digital torque controller and was repeatedly delivered and removed by 20 times respectively. After experiment, evaluation for the change of hexagonal structures and measurement of rotational freedom were performed. Result : The results were as follows; 1. Wear of contact area between implant fixture and abutment was considerable in both 3i and Avana system. Scratches and defects were frequently observed at the line-angle of hexagonal structures of implant fixture and abutment. 2. In the SEM view of the external hexagon of implant fixture, the point-angle areas at the corner edge of hexagon were severely worn out in both systems. It was more notable in the case of 3i systems than in that of Avana systems. 3. In the SEM view of the internal hexagon of abutment, Gingi-Hue abutment of 3i systems showed severe wear in micro-stop contacts that were machined into the corners to prevent rotation and cemented abutment of Avana systems showed wear in both surface area adjacent to the corner mating with external hexagon of implant fixture. 4 The mean values of rotational freedom between the external hexagon of the implant fixture and internal hexagon of abutment were 0.48$\pm$0.04$^{\circ}$ in pre-tested 3i systems and 1.18$\pm$0.25$^{\circ}$ after test, and 1.80$\pm$0.04$^{\circ}$ in pre-tested Avana systems and 2.61$\pm$0.16$^{\circ}$ after test. 5. Changes of rotational freedom after test shouted statistical)y a significant increase in both 3i and Avana systems(P<0.05, paired t-test). 6. Statistically, there was no significant difference between amount of increase in the rotational freedom of 3i systems and amount of increase in that of Avana ones(P>0.05, unpaired t-test). Conclusion: Conclusively, it was considered that repeated delivery and remove of abutment by 20 times would not have influence on screw joint stability. However, it caused statistically the significant change of rotational freedom in tested systems. Therefore, it is suggested that repeated delivery and remove of abutment should be minimal as possible as it could be and be done carefully Additionally, it is suggested that the means or treatment to prevent the wear of mating components should be devised.

• 대한정형외과스포츠의학회지
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• 제9권1호
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• pp.7-15
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• 2010

전방 슬관절 동통 증후군은 여러 가지 형태의 다양한 원인으로 서서히 양측 슬개-대퇴 관절 내 또는 주위에 동통을 야기하는 증상이다. 원인으로는 하지의 부적절한 생역학, 전체적인 신전 기전의 병변, 슬개-대퇴 관절 병변, 슬개골 자체의 병변 또는 부정정렬, 단단한 연부조직, 약화된 근육 등이며, 전방 슬관절 동통 증후군을 평가하기 위해서는 슬개골 정열의 측정이 필요하고 현재 이학적 검사 및 방사선 검사 등 다양한 방법이 사용되어 진단 및 치료 정도를 평가하는데 사용되고 있다. 치료는 슬관절 전방 통증의 원인에 따라 결정되며, 주로 수술적 치료보다는 약물 치료나 대퇴사두근 근력 강화 운동, 함스트링 스트레칭운동 등이 보편적으로 사용되고 있다. 경부목 또는 내측 경골 스트레스 증후군은 전내측 경골 원위 2/3 부위에서 발생되는 통증을 의미하며, 반복적이고 조화되지 않는 충격이 하퇴부에 가해지는 스포츠를 하는 체육인에게 흔히 발생된다. 문제의 원인을 정확히 파악하여 진단하는 것이 치료에 매우 중요하며, 따라서 원인, 치료, 재활 및 예방까지 여러 이론이 보고되었다. 치료는 통증이 심할 경우 휴식과 함께 얼음찜질을 실시하며, 진통제를 복용하여 통증을 완화시켜 주는 것이 좋으며, 또한 다리 근육을 강화시켜 줄 수 있는 운동을 하며, 적절한 재활과 예방적 처치가 추후 재발을 방지하는 데 도움이 된다.

• 한국보건간호학회지
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• 제12권2호
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• pp.67-88
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• 1998

Present study was attempt to explore the relationship between perceived family support and depression and to emphasize the importance or needs of family support in psychological care especially among adolescents. Study subjects comprized of 308 high school students including vocational students in part, and data collection was done in the Kwangju City area in April. 1998. The Moos Family Environment Scale and the Zung's Self-Rating Depression Scale modified by investigators were used as measurement tools of 59 item questionnaire and in data analysis, statistical methods of T-test, ANOVA. and Pearson Correlation Coefficient were utilized. The study findings are as follows 1. The hypothesis of the study, 'the higher the degree of perceived family support among adolescents, the lower the level of depression', was supported (r=-0.4469, p<.001). 2. Some variables in demographic characteristics related to the degree of family support with statistical significance were school division of vacational vs non-vocational(t=-2.02, p<.05), age(f=5.47, p<.01), family monthly income (f=2.49, p<.05), mother's level of education (f=3.01. p<.05), residence at developmental stage (f=2.87, p<.05), personal problem of highest priority at present(f=7.73, p<.001), and family problem perceived by adolescents(f=7.38, p< .001). 3. Items In general characteristics related to the level of depression with statistical significance were sex(t=-2.91, p<.0l). mother's level of education(f=2.53. p<.05). residence at developmental stage (f=3.95. p<.0l). present personal problem of highest priority (f=3.68. p<.1l). and perceived in-family problem (f=4.58. p<.001). 4. The mean score of the degree of perceived family support was 61.26 $(SD=\pm14.45)$ in a range of 21.00 to 96.00 ; that of the level of depression. 43.74 $(SD=\pm8.04)$ in a range of 23.00 to 67.00. which demonstrated that the higher the degree of perceived family support, the lower the level of depression. In conclusion. it was found that the degree of family support perceived by adolescents is a variable affecting the level of depression. Based on the study outcome, further research suggestions can be made as such that repeated studies are needed in order to delineate the various factors affecting family support and depression, and a study involving family support implementation program is required as a nursing intervention for the development of emotional security among adolescents, perceived family support, depression, adolescence.