PURPOSES : This study aimed to examine the effect of fog on the optical properties of taillights and the relationship between luminous intensity and the visibility distance of taillights on the road. METHODS : Changes in luminous intensity were measured using a light meter. Participants subjectively evaluated visibility distance. The artificial fog was reproduced using weather-generating facilities at the Center of Road Weather Proving Ground (CRPG). RESULTS : As expected, the average luminous intensity under intermediate fog conditions was reduced to 72% compared to normal weather conditions and 44% under heavy fog conditions in the case of the tail lamp-only lit condition. In the case of the tail lamp and brake lamp lit condition, the average luminous intensity was reduced to 76% under heavy fog conditions and 55% under intermediate fog conditions compared to normal dry conditions. In addition, the average visibility distance was reduced by 41% when fog conditions changed from intermediate to heavy in the case of the tail lamp-only lit condition and 39% in the case of the tail lamp and brake lamp lit conditions. Changes in visibility distance corresponding to the gradual change in luminous change were evaluated by participants, and the linearly regressed equations for the relationship between the intensity levels and the visibility distance were derived and examined for their meaning in terms of road traffic safety concerning stopping sight distance. CONCLUSIONS : Luminous intensities were suggested, given the design speeds, to satisfy the minimum stopping distances. In addition, the required speed reduction allowances were suggested given the design speeds if the luminous intensity remains unchanged.

Background: Thera-Band, Narrow squats, Kinesiology taping helps in the reduction of loading on the knee joints. Despite the fact that the varus knee negatively affects the alignment of the lower extremities, most of the studies have analyzed each independently. Objectives: To investigate the effects of a complex exercise program consisting of elastic band exercises and squat exercises on the distance between the inner knees and balance in young adults with genu varum. Design: A cluster randomized controlled trial. Methods: The complex exercise group performed resistance exercises using an elastic band. The taping group used kinesiology tape on the vastus lateralis and biceps femoris. To select those to be included in the study, we measured the distance between the knees using digital Vernier calipers and to measure the balance ability, we used a balance training system. The data were analyzed with the independent t-test and paired t-test. Results: The study indicated a significant difference in the distance between the knees between the two groups, but no significant differences in the dynamic balance between the groups. Also, the static balance comparison between the groups according to the intervention method included the trace length, C90 area, C90 angle and velocity. There were no significant differences in the static balance between the groups. In addition, the complex exercise program was more effective than taping. Conclusion: The results of this study demonstrate that the complex exercise program and taping decrease the between both the knee and increase the balance.

해외직구를 비롯한 인터넷 구매 환경에서 소비자들은 실제적인 제품을 보지 못하고 제품의 사진과 제품 정보에 의존하여 의사결정을 내리게 된다. 제품의 사진은 제품의 형태만을 보여줄 뿐이므로 소비자들은 정확한 크기에 대한 정보는 제품 속성을 나타내는 텍스트에 의존하게 된다. 이러한 크기나 양을 표시할 때, 같은 양이나 크기를 나타내는 데에도 여러 가지 단위와 그에 따른 다른 숫자가 사용될 수 있다. 예를 들어 해외 직구 상황에서 30ml 의 향수가 1 fl. oz.로 표시되어 있는 사이트를 발견할 수도 있다. 이러한 상황에서 소비자들은 같은 크기의 제품 이라 하더라도 표시한다고 하더라도 사용된 단위에 따라 크기를 다르게 인식할 수 있다. 즉 큰 숫자로 표현된 사물을 크게 지각하는 다수성 효과가 나타나는 경우도 있고 그 반대로 큰 단위가 사용되면 크게 지각하는 단위효과가 나타날 수도 있다. 이 논문은 이러한 다수성 효과와 단위효과에 영향을 미치는 요소로 심리적 거리 중의 하나인 사회적 거리와 단 위의 친숙성을 제시하고 이들의 조절효과를 살펴 보았다. 이를 위하여 두 가지 실험이 사용되었다. 우선 실험 1 에서는 사회적 거리가 가까울 경우는 다수성 효과가 나타나는 경향이 있고 사회적 거리가 멀 경우에는 단위 효과 가 나타나는 경향이 있다는 것을 알 수 있었다. 그리고 실험 2에서는 단위친숙성이 낮은 경우에는 다수성 효과가 강해지고 단위친숙성이 높은 경우에는 그 다수성 효과가 약해짐을 알 수 있었으며 또 실험 1에서 나타난 사회적 거리의 조절효과는 단위 친숙성이 낮을 경우에는 나타나지 않음을 알 수 있었다.

불투수포장면적의 증가는 도심지 내 열환경 악화, 물순환체계 단절 등의 문제점과 더불어 인간의 여러 가지 신체적･정신적 질병에 원인이 되기도 한다. 이에 도시공원 내 거리에 따른 공기이온 실태와 거리별 기상요소 및 공기이온과의 상관성을 분석하여, 향후 도심지 내 대규모 도시공원 조성 혹은 리모델링에 있어서 기후적 측면의 건강성을 고려한 도시공원 조성의 기초자료로 제시하고자 하였다. 연구대상지는 서울시 송파구 올림픽공원을 대상으로 거리에 따라 4개 유형으로 구분한 뒤, 구간을 A, B로 분류하였다. 측정지점은 80지점을 선정한 후 토지피복 및 식생현황을 조사한 후 기상요소, 공기이온을 측정하 였다. 첫째, 구간별 녹지율은 A구간 Center(90%) > Inner(70%) > Outer-inner(10%) = Outer(10%), B구간 Center(100%) > Inner(60%) > Outer-inner(30%) > Outer(0%) 순이었다. 둘째, 기상요소의 경우 기온의 경우 Outer(24.18℃) > Outer-inner(22.90℃) > Inner(22.43℃) > Center(21.719℃)으로 분석되었으며, 상대습도의 경우 Center(46.49%) > Inner(43.36%) > Outer-inner(42.41%) > Outer(38.53%)으로 분석되었다. 셋째, 공기이온 중 양이온의 경우 Outer(435.71ea/㎤) > Outer-inner(415.16ea/㎤) > Inner(389.46ea/㎤) > Center(352.64ea/㎤)의 순이었으며, 음이온의 경우 Center(569.72ea/㎤) > Inner(499.83ea/㎤) > Outer-inner(410.58ea/㎤) > Outer(292.02ea/㎤) 순으로 Center로 갈수록 증가하는 것으로 분석되었으며, 도로와 가까워질수록 감소하는 것으로 분석되었다. 이온지수의 경우 Center(1.67) > Inner(1.31) > Outer-inner(1.08) > Outer(0.71)으로 분석되었다. 넷째, 상관성 분석결과 정(+)의 상관인 것은 음이온, 이온지수로 도로로부터 공원 Center로 갈수록 증가하는 것으로 분석되었으며, 부(-)의 상관인 것은 기온, 일사량, 양이온으로 도로와 가까워질수록 증가하는 것으로 분석되었다.

PURPOSES : In this study, the relationship between the types of road pavement markings and the visibility distance under adverse weather conditions was evaluated. METHODS : Rainy and foggy conditions at the weather proving ground were replicated in this study. The researchers recorded the visibility distance corresponding to each experiment scenario comprising the weather conditions and pavement marking types. RESULTS : Visibility distances under adverse weather conditions decreased more than those of normal weather conditions. Under rainy conditions, the average visibility distance across all pavement markings decreased by 33%. However, the average visibility distance across all pavement markings foggy conditions decreased by 46.8%. Based on the test results of the visibility distance, the speed reduction rates corresponding to the adverse and normal weather conditions, i.e., 24% and 36% speed reduction under rainy and foggy conditions, respectively, were established. CONCLUSIONS : This study validated the reduction in the visibility distance affected by weather conditions by applying actual road scale weather proving ground. In addition, speed reduction was recommended for safe driving under adverse weather conditions.

PURPOSES : The purpose of this study is to analyze the impact of the level of the light-environment and the driver's visual ability on the change in the driver's perception of a forward curved section at night. The study also aims to identify factors that should be considered to ensure safety while entering curved sections of a road at night. METHODS : Data collected from a virtual driving experiment, conducted by the Korean Institute of Construction Technology (2017), were used. Logistic regression was applied to analyze the effects of changes in the light-environment factors (road surface luminance and glare) and the driver’s visual ability on a driver's perception of the road. Additionally, analysis of the moderated effect of visual ability on light-environment factors indicated that the difference in drivers’ visual abilities impact the influence of light-environment factors on their perception. A driver's ability to perceive, as a response variable, was categorized into 'failure' and 'success' by comparing the perceived distance and minimum reaction sight distance. Covariates were also defined. Road surface luminance levels were categorized into 'unlit road surface luminance' (luminance ≤ 0.1 nt) and 'lit road surface luminance' (luminance > 0.1 nt), based on 0.1 nt, which is the typical level observed on unlit roads. The glare level was categorized as 'with glare' and 'without glare' based on whether the glare was from a high-beam caused by an oncoming vehicle or not. The driver's visual ability level was categorized into 'low visual ability' (age ≥ 50) and 'high visual ability' (age ≤ 49), considering that after the age of 50, the drive’s visual ability sharply declines. RESULTS : The level of road surface luminance, glare, and driver's visual ability were analyzed to be significant factors that impact the driver's ability to perceive curved road sections at night. A driver's perception was found to reduce when the road surface luminance is very low, owing to the lack of road lighting ('unlit road luminance'), when glare is caused by oncoming vehicles ('with glare'), and if the driver's visual ability level is low owing to an older age ('low visual ability'). The driver's ability to perceive a curved section is most affected by the road surface luminance level. The effect is reduced in the order of glare occurrence and the driver's visual ability level. The visual ability was analyzed as a factor that impacts the intensity of the effect of change of the light-environment on the change of the driver's ability to perceive the road. The ability to perceive a curved section deteriorates significantly in 'low visual ability' drivers, aged 50 and above, compared to drivers with 'high visual ability,' under the age of 49, when the light-environment conditions are adverse with regard to the driver’s perception (road surface luminance: 'lit road surface luminance'→'unlit road surface luminance,' glare: 'without glare'→'with glare'). CONCLUSIONS : Supplementation, in terms of road lighting standards that can lead to improvements in the level of light-environment, should be considered first, rather than the implementation of restrictions on the right of movement, such as restricting the passage of low visual ability or aging drivers who are disadvantageous in terms of gaining good perception of the road at night. When establishing alternatives so that safety on roads at night is improved, it is necessary to consider improving drivers' perception by expanding road lighting installation. The road lighting criteria should be modified such that the glare caused by oncoming traffic, which is an influential factor in the linear change in perception, and the level of light-environment thereof are improved.

본 연구에서는 국제 전략적 제휴에서 파트너 간 문화적 거리가 점진적 혁신 성과와 급진적 혁신 성과에 미치는 효과에 대해 분석하고자 하였다. 이에 더하여, 동일 산업 간 제휴 및 이종 산업 간 제휴의 차이로 대표되는 파트너 간 산업 지식 기반의 차이가 독립변수의 효과를 조절하는지 규명해 보고자 하였다. 구체적으로, 문화 차이에서 비롯된 파트너 간 인지적 거리(recognition distance)가 혁신에 필요한 학습 능력에 영향을 미친다는 이론적 논의와 이러한 영향력이 산업 환경의 지식 기반 차이에 따라 달라진다는 관점 하에 가설을 설정하였다. 본 연구의 가설 검증을 위해서는 2009년부터 2012년까지 4년의 기간 동안 139개의 국내 코스닥 상장 기업이 체결한 364건의 국제 전략적 제휴를 표본으로 특허 창출 건수를 종속변수로 하는 음이항 회귀분석(negative binomial regression)을 실시하였다. 분석 결과, 제휴 파트너와의 문화적 거리가 멀수록 점진적 혁신에 긍정적 영향을 미치는 반면, 급진적 혁신에는 부정적 영향을 미치는 것을 확인할 수 있었다.

PURPOSES : This paper is to deliver an engineering design guide currently unavailable that highway engineers can refer to when they need to determine the safe distance between the starting point of the underground highway in a metropolitan area and the access points of the adjacent highway. METHODS : The distance between two different highway points should be sufficiently far to support the number of lane changes that drivers may take comfortably at the cruising speed in critical traffic conditions. RESULTS : The proper distance for the selected case study is calculated to be 160 and 200 m at the cruising speeds of 40 km/h and 50 km/h, respectively, without significant increase in potential conflicts estimated by the combination of the VISSIM and SSAM analysis. CONCLUSIONS : The proposed design method can be referred in urban metropolitan areas where no specific design guide is yet available, and it would prevent the unnecessary increase in construction costs and encourage private-public partnership highway businesses.

Menton (Me) deviation is commonly used for diagnosing facial asymmetry. This study compared angle and distance measurement in determining the severity of Me deviation for facial asymmetry diagnosis. Three-Dimensional Computed Tomographic(3D CT) images of 32 patients (mean age 22.5yrs, SD 3.4yrs; 16 male, 16 female) with facial asymmetry were selected for this study. Angle and distance of Me deviation in each patient were obtained and the severity of Me deviation was determined according to the angle and the distance measurement. The severity of Me deviation by angle and distance measurement was compared and statistical analysis was performed. Eight (25%) showed disagreement in severity of Me deviation between the two measurements. The kappa coefficient on the two measurements was 0.67, showing substantial agreement. It is suggested that both angle and distance measurement be performed in determining severity of Me deivation.

PURPOSES : This study was purposed to investigate whether the current passing sight distance standard is appropriate. Therefore, to determine a safe passing sight distance, data collected from the observations of a two-lane road were implemented in reliability analysis to develop a realistic passing sight distance model. METHODS : First, passing sight distance data were collected for analysis from two-lane roads in Jeollabuk-do. Next, the speed profile was generated based on the collected data in order to analyze driver behavior. Finally, a model reflective of the driving behavior of motorists was developed and compared to the existing passing sight distance standard using reliability analysis. RESULTS : As compared to the existing model for safe passing sight distance, the actual speed of the overtaking vehicle indicated higher acceleration and a longer acceleration duration. The entire model, with exception of the d1 section, was modified to reflect the overtaking behavior of motorists d1. d2 was set to correspond to the time until the vehicles run side by side (t21); Time t22 was set to correspond to the time until subsequent recovery to the main lane, and d3 was set to range between 19 and 47 m following review of the actual passing sight distance data. In addition, d4 was computed to be two-thirds of the distance d2, and the oncoming car was found to drive at a constant speed that was similar to the speed associated with d2 . Analysis of the reliability of the existing Korean passing sight distance standard revealed that the current standard does not recommend a safe passing sight distance for drivers. CONCLUSIONS : As compared to the existing passing sight distance criterion, the actual speed and acceleration that driver apply to overtake a vehicle are higher, and the existing passing sight distance criterion is shorter than the actual passing sight distance. Additionally, the results of reliability analysis revealed that the proposed model developed to reflect driver overtaking behavior has more explanatory power than the existing one. Therefore, it is necessary to introduce new design standards that implement passing sight distance variables that are relevant to local drivers.

본 연구는 유연하고 민첩한 대응이 요구되는 경영 환경에서 리더가 구성원들과 함께 문제해결 과정을 공유하는 참여적 리더십(participative leadership)의 선행요인과 경계조건을 제시하고자 하였다. 참여적 리더십에 관한 기존연구와 계획된 행동 이론에 기반하여, 리더 개인과 관련된 선행요인으로 리더의 자기 지향 완벽주의(self-oriented perfectionism)에 초점을 두었다. 그리고 자기지향 완벽주의와 참여적 리더십 간 관계의 1차적인 경계조건(제1조절변수)으로 구성원의 성장 마인드셋(growth mindset)을 다루었고, 2차적인 경계조건(제2조절변수)으로 구성원의 권력거리성향(power distance orientation)의 역할을 확인 하고자 하였다. 연구 가설에 대한 실증적 검증을 위하여 상사를 둔 국내 직장인들을 대상으로 설문조사를 하였으며, 모든 변수에 대한 측정은 구성원 개인 차원에서 실시하였다. 이를 통해 참여적 리더십의 선행요인으로서 완벽주의의 적응적 측면인 자기지향 완벽주의의 유효성을 검증하고, 그러한 관계에 영향을 미치는 구성원과 조직문화에 관한 조건들을 규명하고자 하였다. 이러한 연구 결과를 바탕으로 적응적 완벽 주의에 관한 보다 활발한 연구의 필요성을 제기하고, 실무적 관점에서 인적자원관리 방안에 관한 시사점을 제공하고자 하였다. 연구 결과는 다음과 같다. 첫째, 리더의 자기지향 완벽주의는 참여적 리더십에 정 (+)의 영향을 미치는 것으로 확인되었다. 둘째, 리더의 자기지향 완벽주의와 참여적 리더십의 관계에서 구성원 성장 마인드셋의 조절효과는 유의하지 않았다. 셋째, 리더의 자기지향 완벽주의와 참여적 리더십의 관계에서 구성원 성장 마인드셋과 권력거리성향의 조절된 조절효과(3원 상호작용효과)는 유의한 것으로 확인되었다. 연구 결과에 관한 시사점과 연구의 한계점 및 향후 연구에 대한 제언을 논의하였다.

PURPOSES: Knowing the scope of deterioration of the concrete slab around spalling is important in determining the size of the partial-depth repair. The change in the material properties of the concrete slab, according to the severity of spalling and distance from spalling, is analyzed herein by performing non-destructive and destructive tests at the field and in the laboratory. METHODS: The test slabs were determined by finding spallings with high or medium severity. The relative elastic modulus was measured near the spalling, far from spalling, and around the slab center using an impact echo equipment. The core specimens were obtained at the measurement positions. An absorption test was performed for the core specimens, while the impact echo and dynamic modulus tests were performed for the upper and lower parts of the core specimens under dry or saturated conditions. A compressive strength test was also performed for the upper and lower parts of the core specimens. RESULTS : The absorption coefficient, relative elastic modulus, relative dynamic modulus, and relative compressive strength worsened as the measurement position became closer to the spalling distress and top of the slab. The worse material properties were measured for the spalling with a higher severity. The moisture condition of the specimens scarcely affected the material properties. CONCLUSIONS : The impact echo test results obtained at the field showed a high correlation with the results of the absorption, impact echo, dynamic modulus, and compressive strength tests performed in the laboratory. Accordingly, a quicker and a more convenient nondestructive soundness evaluation of concrete pavements is expected to be realized using the field impact echo test method.

In this study earthquake records were collected for rock conditions that do not reflect seismic amplification by soil from global earthquake databases such as PEER, USGS, and ESMD. The collected earthquake records were classified and analyzed based on the magnitude and distance of earthquakes. Based on the analyzed earthquakes, the design response spectrum shape, effective ground acceleration, and amplification ratios for each period band are presented. In addition, based on the analyzed data, the story shear force for 5F, 10F, 15F, and 20F were derived through an analysis of the elastic time history for multi-DOF structures. The results from analyzing the rock earthquake record show that the seismic load tends to be amplified greatly in the short period region, which is similar to results observed from the Gyeongju and Pohang earthquakes. In addition, the results of the multi-DOF structure analysis show that existing seismic design criteria can be underestimated and designed in the high-order mode of short- and medium-long cycle structures.

In this paper, an analytical model is developed for electrical conductivity of nanocomposites, particularly polymer/carbon nanotubes nanocomposites. This model considers the effects of aspect ratio, concentration, waviness, conductivity and percolation threshold of nanoparticles, interphase thickness, wettability between polymer and filler, tunneling distance between nanoparticles and network fraction on the conductivity. The developed model is confirmed by experimental results and parametric studies. The calculations show good agreement with the experimental data of different samples. The concentration and aspect ratio of nanoparticles directly control the conductivity. Moreover, a smaller distance between nanoparticles increases the conductivity based on the tunneling mechanism. A thick interphase also causes an increased conductivity, because the interphase regions participate in the networks and enhance the effectiveness of nanoparticles.

Sales of the Korean clothing industry grew to 16.9 percent on-year in 2010, but the growth rate dropped to 3 percent from 2011 to 2016 and the overall market began to slump to 1.1.6 percent in 2017. The competitiveness of clothing companies is also a major sector in logistics capability, and the average logistics cost of domestic clothing companies is 8.3 percent of sales in 2011, higher than the average 8 percent of domestic industries, and 36.4 percent of the total storage cost in 2011, higher than the 28.8 percent share of the total storage cost of domestic companies. As domestic production conditions such as wage hikes and labor disputes worsened in the 1990s, production facilities were rapidly moved overseas, which led many clothing companies to have no production facilities or a minimal production base in Korea and focus on marketing and design capabilities. The total storage capacity and storage efficiency of the logistics center became very important as the products were changed to the form of mass warehousing and small-volume forwarding. Research shows that building column spacing, a model of this research, can affect the amount of hanger rack storage empirically, so for sustainable growth of clothing companies, it is necessary to improve competitiveness in the logistics market by reducing costs and improving efficiency to overcome difficulties in corporate management. Because logistics costs are 8.3 percent and operating profit to sales ratio is 2 percent, it is expected that operating profit will increase by 41.5 percent if logistics costs are reduced by 10 percent. If 10% of storage cost is saved based on storage cost, operating profit is expected to increase by 15% To strengthen the competitiveness of the clothing industry, a reduction in logistics costs is essential. Therefore, the purpose of this study is to provide hints that logistics experts can have empirically small amounts in reducing storage costs through column spacing adjustment of logistics centers that have not been dealt with statistically until now, and to contribute to the continued growth of clothing companies and the development of the domestic logistics industry.