• 한국터널지하공간학회 논문집
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• 제10권4호
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• pp.405-420
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• 2008

전기비저항 탐사법은 터널 주변 지반 혹은 암반의 안정성을 조사하기 위해 사용되는 물리탐사법 중의 하나이다. 다양한 물리탐사법 중에서도 전기비저항 탐사법은 터널설계 단계에서 미리 소사가 수행되어 시공비용을 절감하고 안정성을 확보하기 위한 중요한 자료로 이용되고 있다. 현재 전기비저항 탐사 자료의 해석은 주로 1회의 단일 측정 자료를 대상으로 이루어지고 있지만, 터널 굴착이나 기 굴착된 터널의 유지관리를 위해서는 터널 주변의 시간에 따른 지하수의 분포상황 변화 등이 관측되어야 한다. 이를 위해서는 모니터링 기법이 도입되어야 한다. 따라서 터널 굴착에 따른 전기비저항 변화 파악을 위하여 격자형 측선을 설치하여 총 6회의 전기비저항 모니터링을 수행하였다. 또한 모니터링 시스템을 통해 조사지역에 분포하는 단층대에 상세한 정보를 제공함으로써 안전시공에 예측 시스템으로 가능유무를 평가하고자 하였다.

• 대한치과교정학회지
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• 제26권6호
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• pp.667-676
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• 1996

We have examined the in vitro stage-related chondrogenic potential of human mandibular and limb bud mesenchyme cells using micromass culture. Our results indicate that limb bud mesenchyme cells as early as stage 16 by Carnegie system (37 days), well before the initiation of in vivo chondrogenesis, have chondrogenic potential which is expressed in micromass culture. These results are correlated with stage-related chondrogenic potential of human limb bud in vivo as a result of Alcian blue staining. The proliferation of chondrogenic cells increased in the first 3 days after culture and then decreased. These results were correlated with the cell cycle analysis of which the number of $G_0^1/G_1$ phase increased markedly after 3 days of culture, while the percentage of cells in S phase was decreased. On the other hand, it was rarely differentiated in the mandible. We examined the effects of two PKC modulators such as phorbol 12-myristate 13-acetate (PMA), a potent activator of PKC, and staurosporine (STSN), an inhibitor of PKC. PMA inhibited the chondrogenesis, whereas STSN promoted the chondrogenesis in a dose dependent manner. In addition, PMA exerted no inhibitory effect when the cells were pretreated for 24 h with STSN, implying that the chondrogenic events might be settled at an early step in vitro and FKC may act as a negative modulator. Collectively, these results demonstrate, for the first time, the stage-related chondrogenic potential of human mandibular and limb bud mesenchyme cells and the role of PKC during chondrogenesis in vitro & in vivo.

• 복식
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• 제64권2호
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• pp.113-125
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• 2014

Creative thinking requires an ability to draw ideas on the given topic in a given time period with concentration. For this, the development process of design concept on the topic was collected through experiments and interviews targeting 10 fashion education experts and 10 clothing majors. After the analysis, the results are as follows: First of all, divergent thinking was done to find as many ideas and possibilities as possible at the step of expanding the topic by analogy. This showed characteristics of spreading thoughts through the spread of lexicon to professional field knowledge of learned, individual's cultural background, other art fields. Second, abstracted and designed words that are expanded and listed by the topic analogy were specified the topic gradually through the free combination method between lexicons. The sentences made by the combination of lexicons were interpreted through the serial listing method, in which the connection between sentences had the meaning of orderly cause and effect form, and the parallel listing method that treated information at once. Third, the few characteristics of the procedure that visualizing into the specific design are as follows. Firstly, the method to transform image that lexicon has into the one appropriate to the topic, the case that reflects external characteristics of selected designed word, and the case which reflects as the extrinsic expression of personal immanent and tactic desires. This study has its means to propose methods and directions to help create more creative and systematic ideas by analyzing the characteristics that appeared during the process of thinking language-oriented design.

• 한국안전학회지
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• 제35권3호
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• pp.105-115
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• 2020

This study compares the difference of fit factors (FF) and visual acuity according to masks and eyeglasses preferences for 54 participants. We the precautions and behaviors of discomfort when wearing masks of eyewear wearers. Contact lens discomfort and priority action of complaints was investigated Glasses fitting factors is Optical Center Height(OH), Vertex Distance(VD) and Pantoscopic Angle(PA). We measured those factors and expressed by the ratio of standard point and change point. Quantitative fit factor was measured by Portacount Pro+ 8038. Also, we selected to 6 exercises among 8 exercises OSHA QNFT (Quantitative Fit testing) protocol to measure the fit factors. The pass/ fail criterion of FF was set at 100. Visual acuity(VA) test chart is developed by Chunsuk Han was used, Descriptive statistics was performed. Descriptive statistics(SAS ver 9.2), it is used geometric means, Wilcoxon analysis(P=0.05) When wearing the mask preferentially, fit factor(FF) was high according to the step of glasses fitting parameter. on the other hand, when the glasses first choice, the visual acuity(VA) was high. there was no significant difference. In the case of fit factor (FF), mask first choice/ glasses first choice is OH (p=0.671/ p=0.332), VD (p=0.602/ p=0.571) and PA (p=0.549/ p=0.607). Visual acuity (VA), mask first choice/ glasses first choice is OH (p=0.753/ p=0.386), VD (p=0.815/ p=0.557) and PA (p=0.856/ p=0.562). The workers of workplace and office chose glasses but occupational health workers and students chose mask. In case of discomforts, it was suggested to remove the mask and tolerate discomforts. The main discomforts and usual action of lens were dryness, hyperemia, foreign body sensation, ophthalmodynia, decreased vision and glasses wearing. Therefore, it is necessary to develop a mask wearing method education program considering glasses fitting and develop a hybrid model that minimizes inconvenience when wearing glasses and a mask at the same time.

• 한국소음진동공학회논문집
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• 제26권2호
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• pp.157-164
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• 2016

이 논문은 MR 댐퍼를 적용한 맥퍼슨 타입의 반 능동 현가장치의 진동제어에 관한 연구를 보여준다. 맥퍼슨 스트럿의 기하학적 분석을 바탕으로 동역학 지배 방정식이 설립되었으며, 제어기 설계를 위해 평형 점 근처의 비선형적 운동이 선형화하였다. 이어서 시스템의 향상된 반응시간을 위해 새로운 적응 움직임 슬라이딩모드 제어기를 제안하였으며, 시뮬레이션을 통해 범프와 랜덤도로에서 차량으로 가해지는 진동에 따른 제어 성능을 기존슬라이딩모드 제어기 및 스카이훅 제어기와의 비교를 통해 우수성을 평가하였다.

• 대한공간정보학회지
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• 제9권1호
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• pp.39-47
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• 2001

지형의 특성을 공간상에 수치적으로 표현하는 수치지형모형(DTM)은 전산기의 발달과 더불어 최근 건설 분야의 계획 단계에서 광범위하게 적용이 되고 있으며, 특히 도로설계와 도시계획에 있어서 DTM을 이용한 토공량과 정지표고 및 면적 산정은 대표적인 적용 분야들이다. 따라서, 본 연구에서는 DTM을 이용한 토공량 계산에 정확도에 관련된 요소를 고려하여 최적 토공량 산정을 연구하는데 있어서, 부산광역시 15개 구를 연구 대상지역으로 선정하여 국립지리원 발행 1:5,000 지형도를 수치화하였다. 또한, 토공량과 높이별 정지면적 및 정지표고를 결정하여 향후 절 성토 등으로 인하여 발생 가능한 지형의 변화를 추정할 수 있는 정지표고 산정 모형을 제시하였으며, 그리고 토공량 계산시 사용되는 보간 기법별 토공량의 차이를 분석하였다. 분석결과 역거리보간법이 면적과 표면적 그리고 토공량에서 가장 큰 값을 보였고, 최근린기법이 가장 적을 값이 분포를 나타내었다. 최종적으로 본 연구에서 산정된 토공량은 부산광역시에서 추정한 값들과 매우 근사한 값을 보였다.

• 한국대기환경학회지
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• 제17권1호
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• pp.85-96
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• 2001

The objective of this study is to develop the water spraying which can effectively by applied to the control or suppression of the fugitive dust generated from the scrap metal handling area at the Port of Inchon. As a first step toward this goal, we carried out some preliminary analyses on the chemical composition, physical shape, and particle size distribution of the sample dust. Next, to quantitatively investigate the effect of adding surfactants to the spraying water on the wettability of the sample dust, the Standard Sink Test was carried out for four different surfactants and at six different concentrations using the surfactants considered in this study. Results of from the preliminary analysis indicated that the main chemical component consisting of the sample dust is Goethite(FeO(OH)) and that the particles smaller than 10 ${\mu}{\textrm}{m}$ in geometric diameter occupy about 36% of the sample dust in mass. This result implies that the fugitive dust generated from the scrap metal handling area at the Port of Inchon should affect the environment nearby more than we have expected. This is because of relatively large mass percentage of the small metal particles less than 10${\mu}{\textrm}{m}$ in geometric diameter, what we may call respirable particles. As for the results of the Standard Sink Test, higher surfactant concentration tends to result in the higher wettability of the sample dust for the surfactants considered in this study, which in turn ensures the high particle collection efficiency of the droplets generated from the water spraying system. Based upon this preliminary results, studies to develop more sophisticated scaled model for dynamic test in underway and the effort to find the best surfactants as well as the optimum operating conditions are being made at the same time.

• 한국운동역학회지
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• 제17권2호
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• pp.1-9
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• 2007

Walking is not only an essential component of the human mobility, but also is a good exercise. Inability to walk freely can reduce an individual's quality of life and independence substantially. Being a relatively low impact activity, walking is particularly good for the elderly and research has shown that regular walking in the elderly reduces the chance of fall-related injuries and mental diseases as well. In spite of the documented benefits of regular walking, it is still difficult to walk without the aid of assistive devices for the frail elderly who have lower extremity problems. Assistive walking devices(AWD), such as crutches, canes, hiking-poles, T-Poles and walkers, are often prescribed to the elderly to make their walking be safe and efficient. Many researchers have demonstrated the effects of AWDs such as reducing lower extremity loading, improved dynamic/gait stability, yet, no study has been done for gait pattern when the elderly gait with AWDs. Therefore, the purpose of this study was to examine whether T-Poles, one of the AWDs, change the elderly gait pattern. Eight community-dwelling female elderly participated in this study. Laboratory kinematics during walking with T-Poles(PW) and with out T-Poles(NPW) was assessed. PW showed significant increase in step width, stride length, gait velocity and decrease in swing time. No significances were found in lower body joint angles but meaningful trend and pattern were found. Maybe the reason was due to the participants. Our participants were healthy enough so that the effect of T-Poles was minimum. PW also showed typical gait phases which are no single support phase during a gait cycle. It indicates that walking with T-Poles may guarantee safe and confident walking to the frail elderly.

• 대한지역사회영양학회지
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• 제21권1호
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• pp.37-52
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• 2016

Objectives: This study was performed to develop an assessment tool for middle aged women's health status based on dietary patterns, which will have practical applications in the working field of health and hygiene, aiming at improving the middle aged women's quality of life through their health improvement. Methods: As a first step, a literature review was conducted and the original data of '2008~2009 Korea Health and Nutrition Examination Survey' were reanalyzed. This analysis identified 65 preliminary questions that may be relevant to the study. After verifying the content validity by experts, the 65 questions were reduced into 51 questions. In order to secure higher validity of the candidate items, verification of their clinical validity was conducted among women aged between 45 and 60 years. Finally, an assessment tool was developed by applying weight and scoring. Results: Selected 51 questions were used to verify clinical validity and the results showed that 20 questions were relevant, nine questions ('regular meal time', 'regular amount of meal', 'intake frequency of dairy products', 'intake frequency of fruits', 'intake frequency of meat products', 'intake frequency of high cholesterol foods', 'intake frequency of salty foods', 'appetite', 'eat breakfast everyday') were related to dietary life. Eleven other questions ('self-rated health status', 'deep sleep', 'smoking', 'frequency of drinking', 'stress levels', 'health-related fitness levels', 'pounding of the heart', 'strange feelings on the skin', 'interfere with daily life', 'menopause will bring you a chance to see the life in a different perspective', and 'body mass index') were selected as valid questions. For the response scale for each question, 5 point Likert scale was used to make total 100 point score. Conclusions: This study is the first attempt to develop a health status assessment tool for middle aged women based on their dietary patterns. We conclude that this tool is expected to be a useful and practical tool in the field.

• Korea-Australia Rheology Journal
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• 제19권4호
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• pp.233-242
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• 2007

We performed a numerical investigation to find out the optimal choice of the spatial discretization in the distributed-Lagrangian-multiplier/fictitious-domain (DLM/FD) method for the solid/fluid interaction problem. The elastic solid bar attached on the bottom in a pressure-driven channel flow of a Newtonian fluid was selected as a model problem. Our formulation is based on the scheme of Yu (2005) for the interaction between flexible bodies and fluid. A fixed regular rectangular discretization was applied for the description of solid and fluid domain by using the fictitious domain concept. The hydrodynamic interaction between solid and fluid was treated implicitly by the distributed Lagrangian multiplier method. Considering a simplified problem of the Stokes flow and the linearized elasticity, two numerical factors were investigated to clarify their effects and to find the optimum condition: the distribution of Lagrangian multipliers and the solid/fluid interfacial condition. The robustness of this method was verified through the mesh convergence and a pseudo-time step test. We found that the fluid stress in a fictitious solid domain can be neglected and that the Lagrangian multipliers are better to be applied on the entire solid domain. These results will be used to extend our study to systems of elastic particle in the Stokes flow, and of particles in the viscoelastic fluid.