Multi-walled carbon nanotube (MWCNT)–copper (Cu) composites are successfully fabricated by a combination of a binder-free wet mixing and spark plasma sintering (SPS) process. The SPS is performed under various conditions to investigate optimized processing conditions for minimizing the structural defects of CNTs and densifying the MWCNT–Cu composites. The electrical conductivities of MWCNT–Cu composites are slightly increased for compositions containing up to 1 vol.% CNT and remain above the value for sintered Cu up to 2 vol.% CNT. Uniformly dispersed CNTs in the Cu matrix with clean interfaces between the treated MWCNT and Cu leading to effective electrical transfer from the treated MWCNT to the Cu is believed to be the origin of the improved electrical conductivity of the treated MWCNT–Cu composites. The results indicate the possibility of exploiting CNTs as a contributing reinforcement phase for improving the electrical conductivity and mechanical properties in the Cu matrix composites.

PURPOSES: This study develops various models that can estimate the pattern of road surface temperature changes using machine learning methods. METHODS : Both a thermal mapping system and weather forecast information were employed in order to collect data for developing the models. In previous studies, the authors defined road surface temperature data as a response, while vehicular ambient temperature, air temperature, and humidity were considered as predictors. In this research, two additional factors-road type and weather forecasts-were considered for the estimation of the road surface temperature change pattern. Finally, a total of six models for estimating the pattern of road surface temperature changes were developed using the MATLAB program, which provides the classification learner as a machine learning tool. RESULTS: Model 5 was considered the most superior owing to its high accuracy. It was seen that the accuracy of the model could increase when weather forecasts (e.g., Sky Status) were applied. A comparison between Models 4 and 5 showed that the influence of humidity on road surface temperature changes is negligible. CONCLUSIONS: Even though Models 4, 5, and 6 demonstrated the same performance in terms of average absolute error (AAE), Model 5 can be considered the optimal one from the point of view of accuracy.

PURPOSES:This study suggests a specific methodology for the prediction of road surface temperature using vehicular ambient temperature sensors. In addition, four kind of models is developed based on machine learning algorithms.METHODS:Thermal Mapping System is employed to collect road surface and vehicular ambient temperature data on the defined survey route in 2015 and 2016 year, respectively. For modelling, all types of collected temperature data should be classified into response and predictor before applying a machine learning tool such as MATLAB. In this study, collected road surface temperature are considered as response while vehicular ambient temperatures defied as predictor. Through data learning using machine learning tool, models were developed and finally compared predicted and actual temperature based on average absolute error.RESULTS:According to comparison results, model enables to estimate actual road surface temperature variation pattern along the roads very well. Model III is slightly better than the rest of models in terms of estimation performance.CONCLUSIONS :When correlation between response and predictor is high, when plenty of historical data exists, and when a lot of predictors are available, estimation performance of would be much better.

OBJECTIVES : Fixed roadside objects are a threat to drivers when their vehicles deviate from the road. Therefore, such roadside objects need to be suitably dealt with to decrease accidents. This study determines the factors affecting the severity of accidents because of fixed roadside objects. METHODS : This study analyzed the crash severity impact of fixed roadside objects by using ordered probit regression as the analysis methodology. In this research, data from 896 traffic accidents reported in the last three years were used. These accidents consisted of sole-car accidents, fixed roadside object accidents, and lane-departure accidents on the national highway of Korea. The accident severity was classified as light injury, severe injury, and death. The factors relating to the road and the driver were collected as independent variables. RESULTS: The result of the analysis showed that the variables of the crash severity impact are the collision location (left side), gender of the driver (female), alcohol use, collision facility (roadside trees, traffic signals, telephone poles), and type of road (rural segments). Additionally, the collision location (left side), gender of the driver (female), alcohol use, collision facility (street trees, traffic signals, telephone poles), and type of road (rural segments), in order of influence, were found to be the factors affecting the crash severity in accidents due to fixed roadside objects. CONCLUSIONS: An alternative solution is urgently required to reduce the crash severity in accidents due to fixed roadside objects. Such a solution can consider the appropriate places to install breakaway devices and energy-absorbing systems.

PURPOSES: This study evaluates the reliability of the patterns of changes in the road surface temperature during winter using a statistical technique. In addition, a flexible road segmentation method is developed based on the collected road surface temperature data. METHODS: To collect and analyze the data, a thermal mapping system that could be attached to a survey vehicle along with various other sensors was employed. We first selected the test route based on the date and the weather and topographical conditions, since these factors affect the patterns of changes in the road surface temperature. Each route was surveyed a total of 10 times on a round-trip basis at the same times (5 AM to 6 AM). A correlation analysis was performed to identify whether the weather conditions reported for the survey dates were consistent with the actual conditions. In addition, we developed a method for dividing the road into sections based on the consecutive changes in the road surface temperature for use in future applications. Specifically, in this method, the road surface temperature data collected using the thermal mapping system was compared continuously with the average values for the various road sections, and the road was divided into sections based on the temperature. RESULTS : The results showed that the comparison of the reported and actual weather conditions and the standard deviation in the observed road surface temperatures could produce a good indicator of the reliability of the patterns of the changes in the road surface temperature. CONCLUSIONS: This research shows how road surface temperature data can be evaluated using a statistical technique. It also confirms that roads should be segmented based on the changes in the temperature and not using a uniform segmentation method.

Composite materials consisting of pure aluminum matrix reinforced with different amounts of graphite particles are successfully fabricated by mechanical ball milling and spark plasma sintering (SPS) processes. The shrinkage rates of the composite powders vary with the amount of graphite particles and the lowest shrinkage value is observed for the composite with the highest amount of graphite particles. The current slopes of time increase with increase in the amount of graphite particles whereas the current slopes of temperature show the opposite trend. The highest thermal conductivity is achieved for the composite with the least amount of graphite particles. Therefore, the thermal properties of the composite materials can be controlled by controlling the amount of the graphite particles during the SPS process.

기상 조건을 고려하여 교통사고 발생 원인과의 관계를 분석한 연구에서는 갑작스러운 온도 또는 기상 상 태의 변화는 교통사고에 영향을 준다는 결론을 제시하고 있다. 특히, 동절기에 기온이 떨어지는 경우, 도로 결빙에 의한 교통사고가 발생할 가능성이 높으며, 도로 표면에서 발생하는 결빙 현상은 운전자가 육안으로 쉽게 관측 할 수 없는 한계를 가진다. 따라서, 노면에 발생하는 결빙은 교통사고의 원인으로 작용 할 수 있 기 때문에, 결빙이 발생한 구간에서 운전자의 주의를 높여 줄 수 있는 대안 등이 요구된다. 결빙 현상은 야 간과 같이 온도가 낮아지는 시간에 발생하므로, 결빙을 예측하기 위해서는 노면 온도에 대한 정보가 필요하 다. 그러나, 노면온도 변화에 직･간접적으로 영향을 주는 대기 기상정보는 거시적(5km*5km 단위) 범위에 서 정보가 제공되므로, 운전자가 주행하는 도로망에 대한 정확한 정보를 제공하는데 어려움이 따른다. 따라 서, 본 연구에서는 운전자가 주행하는 도로망에 대기 온도를 제공 및 예측하기 위해 대기온도, 대기습도, 풍 향 등을 고려한 기상정보와 노면 온도 자료를 활용하여 노면 온도를 예측하는 모형을 개발하고자 한다. 노면 온도 예측 모형을 개발하기 위하여 Thermal Mapping 장비가 장착된 차량을 이용하였으며, Thermal Mapping 장비를 통해 노면온도, 대기온도, 대기습도를 측정한다. 또한, 시스템적으로 GPS가 연계되어 있어서, 정확한 위치 정보의 취득이 가능하며, 노면온도에 영향을 미치는 기상정보는 기상청에 서 수집하여 제공하는 온도, 습도, 풍속 등을 이용하였다. 또한, 지형의 요소를 교량부, 산지부, 평지부, 해안, 내륙을 구분하여 지형적인 요소도 반영 될 수 있도록 하였다. 예측 모형은 비선형 분석 모형을 사용 하여 노면 예측 정확도에 적합한 알고리즘을 사용할 계획이며, 본 연구의 결과는 기상과 관련된 교통안전 관련 연구에 활용될 것으로 기대한다.

PURPOSES : This study is to develop a automate road mapping system using ARASEO(Automated Road Analysis and Safety Evaluation TOol) for road management. METHODS: The road survey van named ARASEO(Automated Road Analysis and Safety Evaluation TOol) was used to generate highway drawings for Korea National Road number 37 automatically. In order to generate the highway drawings for purpose of road management, it is required to acquired the information for highway alignment, road width and road facilities such as safety barrier and road sign. Therefore the survey van acquired and analyzed the road width, median and guardrail data using rear side laser sensor of ARASEO and recognized the traffic control sign and chevron sign using foreside camera images. Also the highway alignment which is the basic information for highway drawing can be analyzed by acquisition the every 1m positional and attitude data using GPU and IMU sensor and developed algorithm. Finally, in this research the CAD based drawing software was developed to draw highway drawing using the analysis result from ARASEO. RESULTS : This study showed the comparison result of the surveyed road width and drawing data. To make the drawing of the road, we made the Autocad ARX program witch run in CAD menu interface. CONCLUSIONS : Using this program we can create the road center line, every 500m horizontal and vertical ground plan drawing automatically.

본 연구는 244,443 도체로부터 얻은 도체특성(성별, 등지방두께 및 도체중), 사육환경(자돈의 성별 분리사육, 돈사의 온도관리 유무, 돈사의 형태, 환기방식, 급수원의 종류, 음수 개선시설의 유무, 돈사의 연간 소독횟수, 돈사의 바닥형태 및 평당 사육두수), 출하방법(선별출하, 출하일령, 등지방두께의 편차 및 도체중의 편차) 및 번식특성과 자돈관리(모돈의 산차, 이유일령, 정액의 분양처 및 자돈의 품종)등의 자료를 바탕으로 돼지의 도체가격에 미치는 영향을 분석하기 위해 실시하였다. 도체특성 변수에서 암퇘지 및 거세돈이 숫퇘지보다 높은 가격을 형성하였으며(p<0.05), 등지방두께 15-29mm 및 도체중 91-95kg가 높은 도체가격을 보였다(p<0.05). 도체가격에 대한 등지방 두께 및 도체중은 도체가격 형성에 각각 90.75%와 90.23%를 차지하였다. 하지만, 사육환경, 출하방법, 번식관리는 각각의 방법별로 가격에 유의적인 차이를 보였으나, 도체가격형성에는 낮은 영향을 미쳤다. 이상의 결과 여러 가지 변수 중 등지방 두께 및 도체중이 도체가격에 큰 영향을 미친 것으로 나타났다.

PURPOSES : This research is to analyze the influence in terms of misreading rate and legibility time for drivers when condensation occurs on the road signs. METHODS : In this research, the dew occurred road signs provided to drivers to measure legibility time and misreading rate to compare with normal road sign. In order to identify the difference of legibility time between normal road sign and dew occurred road sign, the T-test and ANOVA test were used. And the vision system was used to recognize the region of dew occurrence on the road sign, then the brightness of dew occurrence region on the road sign was changed to check the misreading rate of drivers according to the change rate of brightness. RESULTS : The legibility times were measured 2.65s for normal road sign and 4.08s for dew occurrence road sign and misreading rates were measured 2.8% for normal road sign, 21.7% for dew occurrence road sign.

This study was conducted to determine the effect of dietary whole-crop barley silage on average daily feed intake, average daily weight gain, velvet antler yield and economic efficacy in sika deer during growth. A total of 24 sika deer (initially 56.3 kg BW) of 24 months age were allotted in arrangement in a completely randomized design. The three treatments were: T1(hay diet), T2(whole-crop barley silage), and T3(50% hay+50% whole-crop barley silage). Concentrate feed were 1.5% feeding of body weight with all groups. Average daily weight gain of T3 was higher than those of others for the entire experimental period. Average daily feed intake of sika deer in decreasing order was as follows; T1>T3>T2. The velvet antler yield was highest in T3 group (315±112 g) compared with T1 (276±59 g) and T2 (283±108 g). However, there was no significant difference in average daily feed intake, average daily weight gain, velvet antler yield(p>0.05). In economic efficacy, T3 was about 15-29% higher than that of T1 and T2. In conclusion, the mixed feeding of 50% hay and 50% whole-crop barley silage was more effective in average daily feed intake, average daily weight gain, velvet antler yield and economic efficacy in sika deer

Recently, the demand for the miniaturization of package substrates has been increasing. Technical innovation has occurred to move package substrate manufacturing steps into CMP applications. Electroplated copper filled trenches on the substrate need to be planarized for multi-level wires of less than 10μm. This paper introduces a chemical mechanical planarization (CMP) process as a new package substrate manufacturing step. The purpose of this study is to investigate the effect of surfactant on the dishing and erosion of Cu patterns with the lines and spaces of around 10/10μm used for advanced package substrates. The use of a conventional Cu slurry without surfactant led to problems, including severe erosion of 0.58μm in Cu patterns smaller than 4/6μm and deep dishing of 4.2μm in Cu patterns larger than 14/16μm. However, experimental results showed that the friction force during Cu CMP changed to lower value, and that dishing and erosion became smaller simultaneously as the surfactant concentration became higher. Finally, it was possible to realize more globally planarized Cu patterns with erosion ranges of 0.22μm to 0.35μm and dishing ranges of 0.37μm to 0.69μm by using 3 wt% concentration of surfactant.

본 연구에서는 발레 기본으로서 발레 스탠스의 중요성이 발레교사와 학습자에게 암묵적으로 주지되었음에도 그 실행 수준의 양상이 매우 다양하게 나타나는 원인이 발레 스탠스의 개념, 목 적, 그리고 수행방법의 불확실성에 있다는데 주목하고, 발레 스탠스의 개념과 목적, 그리고 합리 적인 수행방법은 무엇인가를 밝히는데 연구목적을 두었다. 발레 스탠스의 개념은 ‘발레 양식적으 로 정렬한 전신 기본자세’로 정의하였다. 발레 스탠스의 목적은 ‘가장 작은 면적 위에서 몸무게를 이겨내고 전신을 정렬하는 방법으로 발레 양식적으로 움직일 준비 자세를 취하는 것’으로 정의하 였으며, 구체적으로는, ‘몸의 무게와 방향성을 고저, 전후, 좌우의 3차원에서 중립화하여 몸 전체 혹은 부위를 의도하는 어느 방향으로든 몸의 중심선과 무게중심의 변화를 최소화하며 움직일 수 있는 조건을 갖추는 것’이다. 하나 이상의 신체부위가 동시에 관여되고 특정 부위의 수행을 위한 선행 부위가 요구된다는 점에서 단계별로 서로 관련된 부위를 함께 기술하는 것이 학습자의 실제 수행을 촉진하는데 더 적절한 것으로 판단하고, 1단계(발목과 골반각 수정), 2단계(다리의 일직 선), 3단계(척추 양단의 일직선), 4단계(흉곽부의 조정), 5단계(턴아웃, 협응조정, 호흡)로 수행 순 서를 구성하여 초보 수행자의 이해와 실행력을 높이고자 하였다. 발레 스탠스는 전신의 근육이 협응 관여해 발레에서 요구하는 유연성과 근력 발달을 내포하며, 단일 균형에서 다양한 사지의 형태변화가 최소 중심변화로도 가능하다. 발레 스탠스의 이러한 특성이 발레 학습의 효율성과 직 접 관련된다는 점에서 발레 기본의 핵심 조건으로 여겨진 것이라 분석되었다. 차후, 발레 스탠스 에 대한 해부학적 관점에서의 연구, 단계별 적용의 효과에 대한 실증 연구, 관련 근육의 발레 스 탠스에 대한 기여도에 대한 분석이 후행될 필요가 있다.