• Journal of the Korean Geotechnical Society
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• v.23 no.10
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• pp.73-84
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• 2007

For standard piezocones with shoulder filter elements immediately behind the cone tip, general dissipation curves show monotonically decreasing pore pressure from the initial value. However, dilatory dissipation behavior, showing a temporary increase in pore pressure followed by a decrease in the hydrostatic pressure, has been observed in lightly overconsolidated cohesive soils $(1. This unusual dissipation behavior was reported mostly in heavily overconsolidated ground and previous researches were limited to such cases. In this study, the mechanism of dilatory dissipation in lightly overconsolidated cohesive soils was investigated. The relativities of the ground properties evaluated from the CPTu data to the dilatory dissipation were analyzed. And, finite difference analyses on dissipation after cone penetration were performed. It was found that dilatory dissipation occurs in lightly overconsolidated soils since the higher excess pore pressure at the cone face propagates upward to the shoulder filter. Also, it was shown that the ratio of initial excess pore pressure at the cone face to that of the shoulder filter $({\Delta}u_{1i}/{\Delta}u_{2i})$, which is related to overconsolidation ratio (OCR) and hydrostatic pressure $(u_0)$, affects the dilatory dissipation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.79-85
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• 2023

Skid resistance pavement is an accessory to the road and is a facility for the safe driving of cars by increasing the skid resistance of road pavement. In particular, in bad weather conditions such as snow, rain, and black ice, the skid resistance performance of skid resistance pavement greatly affects the safety of road traffic and drivers. However, BPT(British Pendulum Tester) has a test area of only 0.009 m², making it difficult to represent the overall packaging surface. A reliable method of evaluating slip resistance performance is needed for maintaining non-slip packaging. In this study, the conventional BPT test and the skid resistance performance evaluation method of the PFT(Pavement Friction Tester) and µGT(Micro Grip Tester) tests were compared through guidelines and standard investigations and applied to the field skid resistance performance evaluation. In addition, skid resistance pavement with different skid resistance performance was installed at the test-bed and actual road demonstration sites to compare BPN(British Pendulum Number), SN(Skid Number), GN(Grip Number), and to derive correlations for each performance evaluation method. As a result of the experiment, SN and GN showed similar skid resistance performance, and the GN value was derived similar to BPN × 0.01.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.100-107
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• 2024

Currently, in Korea, due to the rapid aging and deterioration of facilities, the minimum Maintenance Level and Performance Level' of facilities are required by the 'Facility Safety Act' or 'Infrastructure Management Act'. Since infrastructure assets have a long lifespan and the pattern of deterioration over time is complex, it is very difficult to maintain infrastructure as 'minimum maintenance state' or 'minimum performance state' by the current way of management. 'Asset Management' shall be performed not only by a technical perspective, but also by an accounting perspective such as cost and asset value. However, due to lack of awareness of 'asset management' among stakeholder, only technical perspective management is being carried out in practice. In order to effectively manage infrastructure assets, complex consideration of various asset value factors such as budget and service as well as safety and durability are required. In this paper, we presented a theory to evaluate and quantify the road network value for efficient asset management of the road network. We also presented a method of simulation to apply the theory presented in this paper. Through simulation and the results derived from this study, it is possible to specify the budget for the future national asset management, and to optimize the strategy for the management of old road facilities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.377-386
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• 2012

Crack sealing has been widely used in the pavement maintenance due to its advantage of repairing the cracks at the preliminary stages. However, it has been analyzed that the crack sealing work process is dangerous and labor intensive. Moreover, quality and productivity of crack sealing work are highly depended on labor experience and skills. Therefore, various crack sealing machines have been researched but revealed many limitations in practical application. This research analyses conventional crack sealing work process and previously developed crack sealing machines in order to develop an automated pavement crack sealing machine which can be practically and widely applied in the construction fields. This paper develops the previously proposed conceptual design by drawing detailed designs and fabricating the hardware(manipulator and end-effector) of the automated pavement crack sealing machine. The crack sealing machine suggested in this paper overcomes limitations of existing crack sealing machines and designed to meet the domestic road conditions and regulations. It is expected that automating the conventional crack sealing method contributes to the improvement of quality, economy and reduce accidents.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.11a
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• pp.91-93
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• 2005

겨울철 주거지역에서 발생되는 PM10은 도로변에서 발생되는 자동차와 같은 배출원에 의한 영향으로 실외의 경우 도로와의 인접한 곳에서 높은 농도를 나타냈으며, 실내의 경우 환기불량으로 외부에 의한 영향이 적은 것을 알 수 있었다. 반면, CO의 경우 저층 I/O 농도비의 차이가 없는 반면 고층은 실내가 실외보다 유의하게 높은 농도를 나타냈으며, 실내 층고간의 차이가 없는 것으로 보아 외부에서 발생되는 배출원에 의한 영향 뿐 아니라 내부에서 발생되는 배출원(조리, 흡연, 난방 등)에 의한 영향을 받는 것으로 사료된다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.05a
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• pp.113-116
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• 2009

보다 바람직한 운전 경험을 제공하기 위하여, 운전자의 감성에 영향을 미치는 요인에 대한 관심이 높아져 가고 있다. 본 연구에서는 운전자의 운전 시의 기분 혹은 감정상태에 영향을 미치는 외부요인으로 도로 소통 상황, 계절, 날씨, 운전 시각, 운전 지역을 추출하였으며 운전자 개인의 감정상태를 결정짓는 주관적이고 심리적인 요인은 배제하였다. 운전 경력 3 년 이상의 운전자를 대상으로 감성 상태는 긍정/부정, 흥분/안정의 2 가지 축으로 나뉘어 측정하였다. 운전자의 무드는 중립을 기준으로 양 극단보다는 중립에 가까운 상태에 주로 분포하였는데 긍정/부정에는 각각 고루 분포한 반면, 흥분/안정에서는 안정 쪽에 더 많이 분포한 것을 알 수 있었다. 또한 다섯 가지 외부 요인들이 모두 운전자의 무드에 영향을 미쳤으며 도로 소통 상황이 긍정/부정과 흥분/안정 모두에서 유의미한 차이를 보였다. 감성의 긍정/부정 축에서는 계절, 날씨, 소통 상황, 그리고 운전 지역이 유의미하였으며, 감성의 흥분/안정 축에서는 운전시간과 소통 상황이 유의미하였다. 본 연구의 결과를 확장시켜 운전자의 감성에 영향을 미치는 외부 요인들을 데이터베이스화하여 운전자를 위한 다양한 제품 및 서비스 개발에 활용될 수 있을 것으로 기대한다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.141-144
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• 2008

도로의 난간에 설치되는 조명기구에 의한 불능글레어의 영향을 가로등 조명방식과 비교, 평가하고 글레어 규제를 위한 적정 휘도 범위를 알아내기 위한 시험을 수행하였다. 실내에 시험실을 구축하고, 글레어 유무 시 휘도대비식별역의 변화를 평가하였다. 글레어 광원에 의한 망막조도가 증가하고, 좁은 시야 각 내에 글레어 광원이 존재하면 휘도대비식별역이 증가하였다. 그리고 낮은 위치에 설치되더라도 시야에서 벗어나 있다면 가로등 조명방식에 비해 불능글레어의 영향이 적은 것으로 나타났다.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2003.03a
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• pp.442-448
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• 2003

최근 장대교량의 건설이 증가하고 지진에 대한 관심이 고조되면서 교략의 내진설계와 면진설계가 교량설계의 주요항목으로 자리잡게 되었다. 특히 최근 ILM교량과 같은 다경간 장대교의 경우 지진시 교량의 상부구조와 하부구조를 격리시켜 주기를 변화시키는 LRB를 이용한 면진설계가 주로 이루어지고 있다. 그러나 아직까지 국내에는 Mt5의 거동과 기본성능에 대한 실험데이터가 절대적으로 부족하며, 따라서 그 특성을 엄밀히 검증하지 못한 채 고속도로 및 국도상의 교량에 LRB를 다수 사용하고 있는 현실이다. 본 연구에서는 실교량에 사용될 LRB에 대하여 기본성능 중의 하나인 피로마모시험을 수행함으로써 온도하중과 같은 반복하중에 대한 LRB의 피로거동을 모사하고 피로시험 전.후의 기본성능의 변화를 파악하였다. 이러한 LRB의 기본성능에 대한 실험온 LRB의 성능에 대한 검증과 함께 LRB의 거동에 대한 불확실성을 줄일 수 있는 기본 자료로 축적할 수 있으며, 현재 한국도로공사 도로교통기술원에서 마련중인 지진격리장치(LRB) 성능시험기준(안)의 정립에 기초 자료로참고하고자 한다.

• Journal of Institute of Convergence Technology
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• v.4 no.2
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• pp.67-70
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• 2014

Recently EU has been recognized that there is a difference of emission quantity between emission certification test mode and real-road driving test. Accordingly the European Commission is currently preparing to require real-road testing as part of the passenger car type-approval process in the EU. vehicle manufacturers from 2017 are expected to test new vehicles not only under laboratory conditions but also on the real-road, using PEMS equipment. Therefore the purpose of this study is to analyze the emission and Fuel Economy of CVS-75 mode test using chassis dynamometer and RDE test using PEMS equipment by PHEV passenger car.

• Journal of Auto-vehicle Safety Association
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• v.4 no.1
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• pp.5-11
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• 2012

This paper discusses the evaluation of the safety impact of the Adaptive Cruise Control (ACC) system in Korea. To evaluate the safety impact, this paper suggests an analysis method by using the test scenario and field operational test data. The test scenario is composed to represent the main component factor of the ACC system and ACC related accident situation such as rear-end collision, lane-change, and road-curvature, etc. Also, from the field operation test data, the system's potential to increase the safety can be measured ideally. Besides, field operational testdata was used to revise the expected safety impact value as Korean road conditions. By using the proposed evaluation method, enhanced safety impact of the ACC system can be estimated scientifically.