PURPOSES: The objective of this study is to evaluate the tack-coating material’s properties using the bitumen bond strength(BBS) test and damping test as function of changed curing times. In this study, bonding strength tests were performed according to the curing time of tack coating materials. METHODS : In order to investigate bonding characteristic of tack coating materials, the Pneumatic Adhesion tensile Testing Instrument(PATTI) device is used to measure the bond strength between the tack coating materials and aggregate substrate based on the AASHTO TP-91. Also, damping test as in situ test was used to determine an appropriate traffic openting time for construction vehicle. Four different tack-coating materials were used in this study. The BBS tests were performed a one hour curing and testing temperatures of 5℃, 15℃, and 25℃. Damping test was conducted at 30min, 60min, 90min, and 120 min of curing times with temperatures of 20℃ and 30℃. RESULTS and CONCLUSIONS : The BBS test results show various bond strength as function of tack coat materials. At the same testing condition, A tack coat material shows almost two times higher than D tack coat materials although both materials are satisfied the criteria of material’s physical properties. Also, Dampting test results shows similar trend with BBS test result. The damping test result was significantly changed as function of tack coat materials. Based on this study, the tack coating material’s curing time is very important. Therefore, both curing time and the bond strength’s characteristic has to be considered in standard specification.

PURPOSES: An conventional method for electric power generation is converting thermal energy into mechanical energy then to electrical energy. Due to environmental issues such as global warming related with CO2 emission etc., were the limiting factor for the energy resources which resulting in extensive research and novel technologies are required to generate electric power. Thermal energy harvesting using thermoelectric generator is one of energy harvesting technologies due to diverse advantages for new green technology. This paper presents a possibility of application of the thermoelectric generator、s application in the direct exchange of waste solar energy into electrical power in road space. METHODS : To measure generated electric power of the thermoelectric generator, data logger was adopted as function of experimental factors such as using cooling sink, connection methods etc. Also, the thermoelectric generator、s behavior at low ambient temperature was investigated as measurement of output voltage vs. elapsed times. RESULTS: A few temperature difference between top an bottom of the thermoelectric generator is generated electric voltage. Components of an electrical circuit can be connected in various ways. The two simplest of these are called series and parallel and occur so open. Series shows slightly better performance in this study. An installation of cooling sink in the thermoelectric generator system was enhanced the output of power voltage. CONCLUSIONS : In this paper, a basic concepts of thermoelectric power generation is presented and applications of the thermoelectric generator to waste solar energy in road is estimated for green energy harvesting technology. The possibility of usage of thermoelectric technology for road facilities was found under the ambient thermal gradient between two surfaces of the thermoelectric module. An experiment results provide a testimony of the feasibility of the proposed environmental energy harvesting technology on the road facilities.

현재 청정에너지 확보에 대한 기술은 전 세계적으로 큰 관심을 가지고 있다. 이에 대한 접근법 중 가장 주목을 받고 있는 것은 에너지 하베스팅 기술이다. 에너지 하베스팅은 기존 구조물에서 낭비되어 지는 풍 력, 태양광·열과 같은 에너지를 전기에너지 및 열에너지로 변환하여 사용할 수 있도록 하는 기술이다. 그 중 온도 차이에 의해 전기를 생산 할 수 있는 발전소자를 이용하여 콘크리트 포장도로에 적용하고자 한다. 콘크리트 포장도로의 표면은 하루 중 가장 태양열에 오랜 시간 노출되는 구조물 중 하나이며, 그로 인하여 콘크리트 구조물의 상부와 하부의 온도차이가 발생하게 된다. 본 실험에서는 발전소자의 콘크리트 적용의 효율증대를 위해 알루미늄 판을 부착시킨 상태와 부착시키지 않은 상태의 동일 시간대의 전압생성 량을 비교하여 동일한 실험조건(온도, 측정시간, 공시체크기)을 유지한 상태에서 실험해 보았다.

This study investigated the antioxidant effect of Taraxacumofficinale on the qualitycharacteristics of Yugwa during storage. Total polyphenol content was higher than total flavonoid content. DPPH radical scavenging activity and antioxidative index of Taraxacum officinale ethanol extracts were significantly (p<0.05) lower compared with those of Vit.C, whereas they were similar with those of BHA. The L, a, and b levels of Yugwa significantly (p<0.05) decreased with increasing amount of Taraxacum officinale powder; 6% Taraxacum officinale powder showed the lowest L and b levels. Hardness was unaffected by Taraxacum officinale content during the storage period. Brittleness of Yugwa was significantly (p<0.05) lower in control, 1.5%, and 6% Taraxacum officinale powder, whereas 3% Taraxacum officinale powder showed no significant differences during storage. Peroxide value significantly decreased in 3% and 6% Taraxacum officinale powders compared to those of control and 1.5% Taraxacum officinale powder after 4 weeks of storage. Taste, flavor, and crispness showed significant (p<0.05) differences according to Taraxacum officinale concentration. In conclusion, addition of 3~6% Taraxacum officinale powder provides beneficial effects in terms of storage life of Yugwa without any detrimental effects on quality characteristics.

PURPOSES: This research investigates traffic noise characteristics as change the transverse rumble strips shape from rectangular to cylinder at toll plaza of highway. METHODS : The traffic noise was investigated at two different places at toll plaza of highway. One is modified grooving, another is employed cylinder shape of TRS instead of rectangular shape of TRS. A measurement of traffic noise was conducted at same location and time period. The traffic volume information was gotten from office of highway office and vehicle speed was measured by speed measuring device. The traffic noise measurement was conducted from 13:00 to 23:00 and by pass-by method. Also, the traffic noise was measured behind noise barrier. Various distance from noise barrier(7.5m, 30m, 50m) and different heights(1.2m, 3m, and 5m) were parameter for measurement of traffic noise in this study. RESULTS : The class 1 vehicle was contributed from traffic volume which was increased 1,500. However, the distribution of traffic speed didn’t change compare to previous investigated period. From this study, It was found that the external traffic noise was changed as function of geometric shape of TRS. The external noise from modified grooving was less than 1.2dB(A) of the current TRS. A difference of traffic noise was 20dB(A) before and after barrier. It came from a noise barrier effect as reduction of traffic noise. According to investigate a traffic noise distribution near barrier, there is similar noise characteristic as function of height at 7.5m distance from noise barrier. Also, There is no different traffic noise between 30m and 50m from source of the noise of sound barrier. CONCLUSIONS: Based on this traffic noise investigation result, there is a clear characteristic difference as changed TRS shape. The traffic noise was reduced by changed TRS shape. Specially, traffic noise was decreased although the traffic volume was increase for same investigation time and period. It is implied that cylinder type of TRS significantly reduces the traffic noise. The specification of various TRS will be studied in the future.

곤충병원성곰팡이를 이용한 해충방제는 환경 친화적인 방제수단으로 농생태계 에 지속적으로 해충밀도 억제효과를 발휘할 수 있으며, 외국에서는 범국가적 차원 에서 많은 연구가 수행 중에 있다. 국내 친환경 유기농자재 목록공시에 등재되어 있는 244 종의 작물충해관리용 자재 중 미생물로 등록되어 있는 자재는 51종으로 약 21%, 식물성 추출물이 원료 로 등록되어 있는 자재는 141종으로 약 57 % 이상을 차지하고 있다. 본 연구에서는 미생물과 식물추출물이 가지는 각각의 효과를 상호 보완하여 곤 충병원성곰팡이와 식물추출물 합제의 제형화 연구와 더불어 혼합농도 구배에 따 른 살충 효과를 검정한 결과, 산업화 적용 시 경제성을 검토하였을 경우 곤충병원성 곰팡이 1x107 cfu/ml , 고삼추출물 1,000 ppm의 혼합농도에서 각각의 단독 처리구 보다 높은 살충률을 보였으며 경시변화에 따른 약효 저하현상 없이 지속됨을 알 수 있었다. 곤충병원성곰팡이와 식물추출물 합제의 제형화는 장기간 미생물 밀도 안정성 이 낮은 것으로 판단되어, 이를 보완하기 위해 식물추출물에 곤충병원성 곰팡이가 생산하는 2차 대사산물을 합제하는 제형화 연구를 진행 중에 있다.

해외에서는 1960년이후부터 유럽에서 성능보증제도가 운영되기 시작하였다. 도로 및 교량공사에 관하 여 최대 5년의 성능보증제도를 도입하는 방안이 적용되었으며, 1990년대 이후 미국 교통국에서도 성능보증제도를 도입하여 운영하기 시작을 하였으며, 미국내에서는 미시간주에서는 성능보증제도 운영이 가장 활발하게 진행되고 있다. 도로포장 성능보증계약제도(Performance Warranty Contract)는 공사 대상에 대하여 준공이후 일정기간동안 성능기준 이상으로 유지를 시공사에서 진행을 하고 성능보증제도 기간 이 후에 발주청에 유지관리 책임을 이관하는 계약제도이다. 성능보증계약제도는 도로포장을 하는 시공사가 재료, 배합설계, 품질관리 계획, 공법 등을 자율적으로 선택 할 수 있는 자율권을 보장해 준다. 하지만, 도로포장이 시공사에서 관리하는 기간중에 조기파손 또는 긴급보수가 필요한 경우에는 시공사에서 유지 관리비용을 부담하여 보수를 해야 한다. 이처럼, 시공사가 공사관리 및 품질관리를 미흡하게 할 경우, 본인 부담으로 보수해야 한다는 리스크가 계약 상대자인 시공사에게 부담이 된다. 유럽과 미국에서 운영되고 있는 성능보증제도 운영의 장점으로는 시공사에서 자체적으로 시공시 품질 관리 및 장비개선을 통하여 시공 품질 개선을 위하여 공용수명 증가와 함께 유지관리비 절감 효과가 널리 보고되고 있다. 이러한 성능보증계약제도가 국내에 도입이 된다면, 시공사 자체의 기술개발을 유도함으로써, 업체들의 기술력 향상을 통하여, 해외 건설시장에서의 국제 경쟁력을 확보 할 수 있을 것으로 판단된다. 또한, 시공사의 기술 및 품질관리 철저를 통하여 유지관리비용의 절감과 발주처에서 부담하였던 유지 관리 등에 대한 비용 절감을 통하여 국가 예산 효율성을 극대화 할 수 있을 것으로 판단된다. 성능보증계약제도 도입으로 인하여 다양한 효과가 기대됨으로써, 본 연구에서는 국내일반국도 포장공사에 성능보증 계약제도 도입을 위한 시범사업을 준비하고 있다. 성능보증계약제도를 수행하기 위해서는 우선적으로 현 행 2년의 하자보수기간을 5~7년으로 연장에 필요한 하자보수보증증권이 필요하다. 또한, 기존 2년의 하 자보수기간뒤에 발생될 도로파손 위험을 알아보기 위하여 공용년수별 조기파손현황을 조사하였다. 아래 그림과 같이 공용년수 4년차에서부터 파손연장이 증가함을 나타내고 있다. 이 경향을 바탕으로 리스트 분석을 현재 연구중에 있으며, 향후 분석결과를 제시하고자 한다.

국내 일반국도는 대부분의 포장이 아스팔트 포장으로 이루어져있으며, 2011년 말을 기준으로 총연장 13,739km로 전체 도로연장 중 약 105,931km로 약 13%를 차지하고, 포장구간의 연장은 13,459km로써 약 97.6%의 포장률을 나타내고 있다. 이와 더불어 전 세계적으로 지구온난화로 인한 연평균기온 및 해수면 상승, 기습폭우 및 태풍 등과 같은 환경영향은 도로포장체의 성능을 저하시키는 요인으로 작용함으로써 포장수명을 단축시키는 문제로 이어지고 있다. 본 연구에서는 일반국도 아스팔트 포장 구간의 포장재령별 신설 0년, 재령 6년, 재령 10년에 대한 소음측정구간을 선정 한 후, 길어깨 소음측정법(Pass-By methods)을 사용하여 도로교 통소음에 대한 포장재령별 소음특성을 평가하였다. 본 연구를 통해서 그림 2와 같이, 신설 0년의 경우 평균 75.9dB(A), 재령 6년은 77.8dB(A), 재령 10년은 76.7dB(A) 값을 보였으며, 이 차이가 평균 1.9dB(A)를 나타냈다. 따라서 일반국도 아스팔트 포장의 재령이 6년인 시점에서 가장 높은 소음특성을 보였으며, 일반국도 아스팔트 포장의 공용수명이 8년~9년인 점을 감안할 때, 포 장의 공용수명에 인접할수록 소음이 보다 높게 나타난 것으로 판단된다. 하지만, 포장노면의 파손상태 및 주변 환 경 등이 상이함으로써, 이에 대한 향후 추가적인 연구가 필요할 것으로 사료된다.

고속도로 영업소 진입로에는 운전자에게 주의환기를 주기 위해 횡방향 럼블스트립이 설치되어 있다. 이러한 럼블스트립은 대부분 직사각형 형상을 갖고 있다. 럼블스트립의 형상에 따라 소음의 특성이 다르게 나타나는 것으로 알려져 있다. 본 연구에서는 직사각형 형태의 럼블스트립을 원형의 럼블스트립으로 개선함에 따른 소음특성 변화에 대한 연구를 수행하였다. 서울외곽순환고속도로 영업소 광장에 개선된 원형 형상의 럼블스트립을 적용하고, 사후 모니터링을 실시하여 개선 전·후의 소음특성에 대해 분석하였다. 본 연구 결과, 럼블스트립의 개선 전·후 소음특성은 개선후의 교통량이 증가했음에도 소음은 감소하는 것을 알 수 있었다. 차량주행속도는 개선 전·후 모두 약 58km/h로 거의 유사하게 나타났다. 원형의 럼블 스트립이 직사각형 형상의 럼블스트립보다 시간대별로 약 1~3dB(A)의 소음저감 효과가 나타났다. 이런 현장적용의 결과를 볼 때, 횡방향 럼블스트립의 다양한 규격(럼블스트립의 간격, 깊이, 형상 등)에 대한 추가적인 연구를 진행하면 더 우수한 성능의 럼블스트립 규격을 개발할 수 있을 것으로 사료된다.

The development of mobile communication technology is transforming the market of mobile communication devices, which is used to be merely for simple communication, into the one which offers features of personal digital assistant (PDA), fax communica- tion and Internet access. Unlike a mobile phone which comes out as a complete package and whose functions cannot be changed, a smart phone can be upgraded by its user, adding or removing apps as he pleases. OS’s of smart phones are iOS-based Apple, Google Android, Window Mobile, and others. Due to its convenience and powerful features, many people use smart phones its high price. On the other hand, consumer complaints are rising on poor A/S for occasional malfunction. This study analyzes how A/S cases can be classified into groups according to quality factors. We evaluate factors such as consumer impression and consumer satisfaction. By dual quality evaluation using KANO method, we would like to show the different A/S strategy for smart phones, compared with mobile phones.

PURPOSES: This study is to investigate a generated traffic noise when vehicle pass over a transverse rumble strip at toll plaza of highway. METHODS: To investigate traffic noise at toll plaza of highway, Pass-by method which is the most common used for measuring traffic noise was adopted and the traffic noise at toll plaza was measured for 10 min per hour for 11hours(13:00~24:00). RESULTS: The measured traffic noise by pass-by method was changed as function of the transverse rumble strip configuration. Generally, the maximum difference among three noise measurement sections was 7 dB(A). It might be related with traffic speed. Also, the measured traffic noise was strongly generated from a passenger car which was 2 axle. It means that the most of traffic noise on the road is generated at tire/pavement interface of the passenger car. CONCLUSIONS: The traffic noise was strongly related with vehicle speed and transverse rumble strip configuration on the road. For driver safety, the transverse rumble strip is definitely necessary. However, the complaints from residents near highway was increased by traffic noise from transverse rumble strip. Therefore, To satisfy both safety and reduction of traffic noise, the development of configuration of transverse rumble strip is necessary in the further study.

PURPOSES : This study presents the noise level and frequency characteristics investigated in the national highways with the consideration of various measuring conditions and/or methods. METHODS : The noise levels on the asphalt concrete pavement(ACP) and the jointed plain concrete pavement(JPCP) of the national highway were measured and analysed with respect to three variables, i.e., pavement type, surface condition, and measurement distance. The PASS-By method is utilized for the noise measurement and then using CPB spectrum analysis method with 1/3 octave bandwidth, the noise levels and frequency characteristics were calculated for two-second periods before and after the peak noise. RESULTS : Depending on the pavement type, the noise level was changed as the average noise levels are 73.3dB(A) and 78.3dB(A) for ACP and JPCP, respectively. With respect to the effect of surface condition, the average noise levels for crack H(high), M(medium), and L (low) sections are 77.4dB(A), 77.4dB(A), and 78.1dB(A), respectively. Regarding the measurement distance, 1.2meter difference in measuring location reduces 1.6dB(A) of noise level; the average noise levels at 5.3m and 7.5m from the centerline of outer lane are 72.8dB(A) and 71.2dB(A), respectively. It should be noted that the noise levels are slightly different as a function of vehicle speed and type. However, the overall trends for each case was similar. It was found that the domain frequency bands for ACP and JPCP were 400Hz~2000Hz and 500Hz~2000Hz, respectively. CONCLUSIONS : Based on the analysis with the measured noise date from national highway, it was concluded that the noise level and frequency band vary depending on the various conditions. It was also found that some variables significantly affect the noise level while others do not. With further systematic investigation, the comprehensive noise characteristics on the national highway can be achieved. Using such database, it is possible to develop the fundamental noise reduction technology.

PURPOSES : The PMS(Pavement Management System) has been utilized in order to efficiently allocate the limited budget for the maintenance of national highway system. In the PMS of national highway, surface pavement condition is evaluated by using the VI (Visual Index). However, the VI is determined only by considering the cracking rate (%) and rut depth (mm), which is not reflecting the IRI (International Roughness Index) that is known as an important factor of pavement performance. In this study, the NHPCI (National Highway Pavement Condition Index) which includes the cracking rate (%), rut depth (mm), and IRI (m/km) is suggested for determining the rehabilitation methods group. METHODS : First, the rehabilitation methods performed between 2008 and 2010 on the national highway is classified and then, NHPCI is determined for each rehabilitation method. Next, the NHPCI for each rehabilitation method is grouped through the interval estimation of the population mean and T-test analysis. RESULTS : According to NHPCI range, the rehabilitation methods are divided into four categories: Not Required, Preventive Maintenance, Overlay Treatment (with or without cutting), and Full-scale Treatment (i.e., reconstruction). CONCLUSIONS : Based on this study, it is recommended that the appropriate NHPCI range should be determined through the combination of the rehabilitation categories and Decision Procedure of Pavement Distress Condition Visual Index.

PURPOSES: This study is to investigate the Hot In-Place recycling asphalt mixture in Korea using field produced materials. METHODS: Hot In-Place reclaimed asphalt mixture was investigated to evaluate the mixture properties based on various test results such as Marshall Test, Indirect Tensile Test, TSR, and Wheel Tracking Test. These test values were compared with domestic standard specification. RESULTS: The result of the laboratory experiment indicates that the Hot In-Place Reclaimed(HIR) asphalt mixture produced at the field constrution site was satisfied all of the test criteria such as Indirect tensile test, Marshall and TSR test, and wheel tracking test. During the test, the research team found that current HIR system is required an extention of mixing time to improve quality and to reduce variation of sample to sample. Although the current HIR mixture was passed the test criteria, there is a potential capability to enhance the mixture properties as extend mixting time. CONCLUSIONS: Based on these laboratory test results, It would be concluded that domestic HIR mixture's properties were satisfied all standard specification related with evaluation of recycling asphalt mixtures. Based on this case study result, there is a chance to save construction cost and increase the usage of reclaimed asphalt concrete in the future.

PURPOSES: This study evaluated a measuring technique for tire-pavement interaction noise that uses a noble close proximity (NCPX) method as well as for noise level measured inside of a car (e.g., Inside Noise Level) in term of rumble strips constructed at a tall gate. METHODS: According to the measurements of NCPX and inside noise level (INL), 1/3 octave band frequency analysis and overall noise level calculation were conducted in order to evaluate noise levels of NCPX and INL, depending on types of rumble strips. RESULTS: The tested sections of general concrete pavement surface and two different types of rumble strips were evaluated, using 1/3 octave band frequency analysis and overall noise level. From the analyzed results, it can be concluded that rumble strips generate a relatively huge noise levels when compared to the concrete pavement surface. CONCLUSIONS: Noting that above 3 dBA different noise levels can let drivers know that they are getting close to toll gate; therefore, they should apply their brakes. Thus, the noise levels of rumble strips are required to be reduced, based on considering the neighbors living near toll gates.