PURPOSES : Even when autonomous vehicles are commercialized, a situation in which autonomous vehicles and regular drivers are mixed will persist for a considerable period of time until the percentage of autonomous vehicles on the road reaches 100%. To prepare for various situations that may occur in mixed traffic, this study aimed to understand the changes in traffic flow according to the percentage of autonomous vehicles in unsignalized intersections. METHODS : We collected road information and constructed a network using the VISSIM traffic simulation program. We then configured various scenarios according to the percentage of autonomous vehicles and traffic volume to understand the changes in the traffic flow in the mixed traffic by scenario. RESULTS : The results of the analysis showed that in all scenarios, the traffic flow on major roads changed negatively with the mix of autonomous vehicles; however, the increase or decrease was small. By contrast, the traffic flow on minor roads changed positively with a mix of autonomous vehicles. CONCLUSIONS : This study is significant because it proactively examines and designs traffic flow changes in congested traffic that may occur when autonomous vehicles are introduced.

도시화로 인한 인구이동과 기반시설의 낙후, 환경오염 등은 농촌지역의 쇠퇴로 이어졌으며, 이는 농촌지역 주민들의 생활서비스 저하로 나타났다. 그러나 개발사업 위주의 인프라 확충과 지원금 제공 중심의 정책대안은 농촌지역의 쇠퇴현상을 구조적이고 복합적으로 인식하지 못했다는 측면에서 한계를 나타냈다. 따라서 본 연구의 목적은 농촌지역에서 발생하는 쇠퇴현상과 생활서비스 저하에 대한 구조적인 분석을 통해 인구 증가 정책이 아닌 산업 구조 개편, 농촌 경관 등의 경쟁력 확보 및 생활서비스 제공 등의 정책으로 농촌 생활서비스를 향상시킬 수 있는 전략을 제시하는 것이다. 본 연구의 결과로 첫째, 농촌지역 쇠퇴 현상에 대해 빈익빈 부익부(success to successful)와 처방의 실패(fixes that fail) 원형을 대입했다. 도시로 유입되는 인구의 증가와 성장의 강화는 농촌지역 인구의 감소와 쇠퇴의 악화로 이어지게 되었으며, 농촌쇠퇴에 대한 해결책을 제시하고자 일자리와 지원금을 확충하는 정책은 장기적인 관점에서 난개발로 이어져 농촌쇠퇴가 지속되는 결과로 나타났다. 둘째, 앞선 구조를 바탕으로 농촌지역 생활서비스가 저하되는 시스템에 대해 재정, 인프라, 접근성의 측면에서 구조를 분석했다. 이러한 분석을 바탕으로 인구 유출을 방지하고 지역 주민들의 요구에 따른 생활서비스 공급방안, 접근성의 개선 등 농촌 주민들에게 생활서비스를 지속적으로 제공할 수 있는 전략을 제시하고자 했다. 본 연구의 결과는 농촌지역 쇠퇴현상에 대한 구조적인 분석을 바탕으로 농촌재생 정책에 대한 방향성을 제공한다는 점에서 의의가 있다.

PURPOSES : A highway operates in a continuous flow and has restricted access. When an accident occurs on a highway, the impact on the traffic flow is large. In particular, an accident that occurs in a tunnel has a more significant impact than an accident that occurs in a general section. Accordingly, the management agency classifies the tunnel as a dangerous section and manages a tunnel of more than 1000 m using the Tunnel Transportation Management System. The purpose of this study was to select dangerous tunnels that require intensive management for the efficient management of highway tunnels. METHODS : In this study, for the selection of dangerous tunnels for expressways, all highway tunnels were classified into five clusters by characteristics. The traffic accident severity — equivalent property damage only (EPDO) — for each tunnel cluster was derived through a traffic accident analysis. Based on the severity analysis results, the safety performance function (SPF) for each cluster was established, and the accident risk tunnel was selected based on the potential safety improvement (PSI) value of each tunnel calculated using the empirical Bayes (EB) method for each tunnel cluster. RESULTS : As a result of the analysis, accident risk tunnels were selected based on the PSI values of the tunnels for each highway tunnel group. Finally, 55 hazardous tunnels were identified as hazardous tunnels: 13 tunnels in Cluster 1, 3 tunnels in Cluster 2, 15 tunnels in Cluster 3, 18 tunnels in Cluster 4, and 6 tunnels in Cluster 5. CONCLUSIONS : After classifying all 1232 tunnels on the highway into five clusters according to tunnel characteristics, EPDO analysis was performed for each tunnel cluster. To this end, the SPF for each cluster was constructed, and accident risk tunnels were selected based on the PSI value of each tunnel calculated using the EB method for each tunnel cluster. The tunnel cluster was classified as a typical tunnel type. As a result, most of the first and second values were calculated from cluster E (long tunnel cluster).

본 연구의 목적은 약주의 향, 맛, 목넘김의 특성을 과학적으로 반영하여 이를 객관적으로 표현할 수 있는 향미 평가항목을 도출하고자 하였다. 총 20명의 훈련된 전통주 전문가를 대상으로 3단계의 델파이 기법을 적용하고, 켄달의 W검증을 통해 의견의 타당도와 신뢰도를 분석한 결과, 크게 향, 냄새, 입안감촉 3개의 대영역으로 분류되었다. 각 영역의 하위개념으로 과일, 식물, 곡물, 꽃, 유제품, 한약재, 견과류, 향신료, 발효, 단향의 10개의 상위항목이, 냄새 영역에는 이취가, 입안감촉 영역에는 맛과 입안감촉 2개의 항목이 분류되었다. 각 상위항목을 표현하는 세부항목은 모두 89종이 도출되었다. 첫 번째 향 영역 중 과일은 13종(참외, 메론, 바나나, 파인애플, 딸기, 청사과, 붉은사과, 살구, 자두, 복숭아, 배, 매실, 감귤)의 세부항목이 도출되었고, 식물은 3종(풀, 무, 버섯), 곡물은 8종(옥수수향, 생쌀, 갓 지은 밥, 밀, 조청, 엿기름, 구수한 향(누룽지), 기타 부원료), 꽃은 5종(장미, 국화, 연꽃, 매화, 아카시아), 유제품은 4종(우유, 치즈, 버터, 요거트), 한약재는 12종(인삼류, 뿌리류(도라지, 더덕), 구기자, 오미자, 대나무잎, 연잎, 솔잎, 송순, 생강, 대추, 감초, 쑥), 견과류는 5종(밤, 아몬드, 고구마, 잣, 땅콩), 향신료는 5종(계피, 정향, 바닐라, 후추, 박하(민트)), 발효는 4종(간장, 메주, 숙성향(노주향), 누룩향), 단향은 3종(꿀, 카라멜, 달콤한 향)으로 총 62종이 도출되었다. 두 번째 냄새 영역의 이취 세부항목에는 초산(식초), 아 세트알데히드, 곰팡이, 부티르산, 산취(쉰냄새), 디메틸설파이드, 종이, 먼지, 흙, 고무, 누룩취, 유황, 열화취, 유취(산패)로 총 14종이 도출되었다. 세 번째 입안감촉 영역은 맛과 입안감촉으로 구분되었는데, 맛의 세부항목으로는 단맛, 짠맛, 신맛, 쓴맛, 감칠맛의 5종이, 입안감촉의 세부항목으로는 떫은맛(수렴성), 자극적인, 부드러운, 톡쏘는 맛(탄산), 무게감, 균형감, 여운(지속성), 목넘김의 8종의 세부항목이 도출되었다. 이렇듯 약주의 향미를 과학적으로 분석한 평가항목을 활용하여 약주를 생산하는 산업체, 건강 혹은 새로움을 맛보 기 위해 전통주를 찾는 소비자, 그리고 한국의 전통문화를 알고자하는 외국인에게 우리술의 맛과 향을 과학적으로 알기 쉽게 표현하여 전통주가 세계로 발돋움 할 수 있는 초석이 되었으면 한다.

목적 : 항산화 기능을 가지는 하이드로겔 콘택트렌즈(Hy)를 제조하기 위해 갈릭산(Gallic acid: GA)을 Hy에 상 분리 없이 도입시키는 방법에 관해 연구하고, 갈릭산이 첨가된 렌즈의 물리적 특성 및 항산화 효과를 살펴보고 자 한다. 방법 : 하이드로겔 콘택트렌즈는 실험실에서 열중합방법으로 제조하였다. 갈릭산과의 결합을 위해 사용된 Chitosan(Cs) 은 100~300 kDa(CL), 600~800 kDa(CH) 분자량을 가진 두 종류를 사용하였으며, Hy에 IPN(Interpenetrating polymer network) 방법으로 첨가하였다. 광 투과율은 300~800 nm 파장 범위에서 측정하였으며, 함수율은 중량 법으로 측정하였다. 키토산과 갈릭산 간의 amide bonding은 FT-IR을 이용하여 확인하였으며, 첨가된 갈릭산의 양 은 298 nm에서 측정한 UV 흡광도 값으로 정량하였다. 렌즈의 항산화 효과는 DPPH radical 소거능 분석 방법을 사용하였다. 결과 : 광 투과율은 Hy에서 95%, Hy-CL-GA와 Hy-CH-GA에서 91%를 보였다. 함수율은 Hy에서 50.5±1.2%, Hy-CL-GA에서 52.4±0.7%, Hy-CH-GA에서 55.6±0.6%로 나타났다. 렌즈에 결합된 갈릭산의 양은 Hy-CLGA와 Hy-CH-GA에서 0.30, 0.37 mmol/cm2로 각각 나타났으며, 항산화 효과는 Hy-CL-GA에서 48.23%, Hy- CH-GA에서는 58.32%로 나타나 갈릭산을 첨가한 두 렌즈에서 매우 높은 항산화 기능을 확인할 수 있었다. 결론 : 키토산과 갈릭산을 활용하여 광 투과율과 함수율이 높고 항산화 효과를 가진 기능성 하이드로겔 콘택트 렌즈를 제조하였다. 렌즈에 결합된 갈릭산의 양이 증가함에 따라 함수율과 항산화 효과가 증가하였다. 콘택트렌즈 에 다당류와 폴리페놀류의 화합물을 첨가하는 방법을 제시함으로써 단백질 억제, 습윤성 향상, 항산화 기능 등을 함유한 다 기능성 렌즈 제조에 기여할 것으로 본다.

PURPOSES: We studied the signal operation method with a focus on swift evacuation of people from disaster-affected urban areas. METHODS: We selected Yeouido, which is at a high risk of being affected by natural disasters, as the urban area in our study. The analysis time for the Yeouido network was divided into four stages of six hours each, based on the traffic characteristics. The disaster scenarios were divided into small-scale and large-scale, and the analysis time and the disaster scale were set as the variables. RESULTS: From the analysis, it was found that the evacuation efficiencies were similar in the cases of entry control and increasing the green light duration for the main direction. However, the most effective approach is to apply entry control in case of disasters occurring at dawn and in the evening, with relatively low traffic volume. The most effective method is to increase the green light duration for the main direction of the main line in the time zone. CONCLUSIONS: As the scale of the disaster and the traffic volume increase, there is a limit on the extent to which the evacuation time could be reduced through signal operation. Therefore, signal control is most effective when the traffic volume is low and the disaster scale is small.

PURPOSES : The recent increase in the application of reclaimed asphalt pavement (RAP) calls for more research focusing the evaluation of pavement performance. For this matter, this study aims at evaluating pavement performance using the application rate of RAP. METHODS: To obtain mixtures with RAP aggregate application rates of 10%, 25% and 30%, the gyratory compaction method was applied regarding the mix design process for determining the optimum asphalt content (OAC). Additionally, the in-direct tension (IDT) test, deformation strength test (DST), tensile strength ratio (TSR) test and dynamic modulus (DM) test were conducted to verify the effect of RAP application rate on pavement performance. Based on the above-mentioned results, performance evaluation was done to these RAP application of design or utilization to construction site. The performance evaluation analysis was performed using the Korean Pavement Research Program (KPRP) of second level for the pavement design. RESULTS: From the DST results, the rutting resistance was improved as the application rates of RAP were increased. Additionally, all the IDT and toughness results satisfied the quality standards of the asphalt concrete pavement. However, the results did not conform with the tensile strength ratio standards with the application rates of RAP of 25% and 30%. This means that the standards, which should be considered when the addictive regeneration material is applied to the mixture when the RAP application rate is over 25%, were reflected. CONCLUSIONS : The predicted performance decreased from the second level performance analysis with the increase in the RAP application rates. All the cases satisfied the design standards (fatigue cracking, rutting depth and international roughness index (IRI)). However, the results of them closed to these standards (up to 94% (Fatigue)).

PURPOSES : The use of reclaimed aggregate has been recently increasing with the increase in the amount of waste asphalt concrete. The application of these materials can reduce the properties of the asphalt pavement when compared with the case when recycled aggregate is not used. The objective of this study is to evaluate the performance of the asphalt mixtures with various mix ratios of reclaimed aggregate. METHODS : To measure the performance, the following tests using the mixtures prepared in accordance with the Korea Standards were conducted: Hamburg wheel-tracking test, third-scale model mobile loading simulator test, and dynamic modulus test. RESULTS : The test results of the Hamburg wheel-tracking test indicate that the water resistance was similar in each mixture and the plastic deformation resistance was good in the high-ratio reclaimed aggregate mixture. In the case of the third-scale model mobile loading simulator test, the plastic deformation demonstrated a high resistance in the high-ratio reclaimed aggregate mixture. The results were similar to those of the Hamburg wheel-tracking test; however, the cracking resistance was poor with a high recycled aggregate incorporation ratio. The dynamic modulus test results demonstrated excellent resistance to plastic deformation at a relatively high ratio of reclaimed aggregate admixture. The crack resistance was weakened when a high ratio of reclaimed aggregate mixture was used. CONCLUSIONS: As the reclaimed aggregate content increased, the plastic deformation resistance increased and the crack resistance decreased.