• 동력기계공학회지
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• 제16권1호
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• pp.91-97
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• 2012

It is being accelerated to develop environment-friendly vehicles to solve problems on the energy and environment of earth. The electric driving motor commonly installed in these vehicles has the excellent control capability such as fast response and accurate generation to torque control command. Especially, in-wheel motor has the additional merit such as independently driving each wheel in vehicle. Recently, being developed various control algorithm to enhance the safety and stability of vehicle motion using actively the merits of in-wheel motor. In addition to that, being issued the possibility of enhancing the ride comfort and attitude of vehicle motion such as pitching and rolling. In this paper, investigate the theoretical relationship between the braking/driving force and the motion of sprung mass of vehicle and propose the control method to enhance the ride comfort and attitude of vehicle motion. The proposed control method is proved through the simulation with vehicle model provided by TruckSim software which is commercial one and specializes in vehicle dynamics.

• 수산경영론집
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• 제40권2호
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• pp.27-48
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• 2009

The objective of this paper is to estimate consumer's marginal willingness to pay(MWTP) for cold chain system attributes of mackerel using choice experiment questionnaires. The survey data were analyzed by conjoint analysis method with multinominal logit model. The five cold chain system attributes with $2{\sim}4$ attribute levels were considered : low temperature safekeeping of fishing boats, a kind of transport truck and packing box, using degree of low temperature facility in distribution, mackerel price per fish(1kg). At least 827 people were asked to participate in the survey. The major findings and implications of this study can be summarized as follows : The estimated multinominal logit model is statistically significant and the total consumers willingness to pay for the improved cold chain system attributes is 6,476 won (per kg). Compared with the base price(2,500 won/kg), the estimated MWTP is 2.5 times higher than the base price. Therefore, the consumer has a willingness to pay for the fresh and safe fish products, even though more money is paid. To satisfy the consumer's needs, cold chain system is necessary in point of long-term. In this reason, The government's policy support is needed for promoting cold chain system in fishery, and a master plan should be prepared.

• 지구물리와물리탐사
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• 제23권4호
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• pp.230-242
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• 2020

201 6년 9월에 발생한 경주지진원 구역에 대한 정밀 지질구조 규명을 위해 MT 탐사를 적용하였다. 경주지역의 MT 측정자료는 조사지역 인근의 지하철, 전력선, 공장, 주택, 농경지에서 발생된 전기적 잡음과 철도, 도로에서의 차량잡음 등으로 인해 측정자료 왜곡이 심하게 발생되었다. 이 연구에서는 고속철도 및 고속도로와 인접한 4개소의 MT 탐사자료에 기계학습 기법을 적용하여 차량잡음이 포함된 시계열을 분류하였다. 고속열차 잡음이 포함된 시계열에 대해서는 확률적 경사 하강법, 서포트 벡터 머신과 랜덤 포레스트 3가지의 분류모델을 적용하여 그 결과를 비교하였다. 대형트럭 잡음이 포함된 시계열 자료에 대해서는 Hx 성분, Hy 성분과 Hx & Hy 합성성분 크기에 대한 3가지의 샘플 자료를 준비하였으며 랜덤 포레스트 분류모델을 구성하여 그 성능을 평가하였다. 마지막으로 차량잡음 제거 효과 분석을 위하여 차량잡음 제거 전후의 시계열, 진폭 스펙트럼과 겉보기비저항 곡선을 비교하였으며, 이를 통해 차량잡음이 영향을 미치는 주파수 대역과 차량잡음 제거 시 발생될 수 있는 문제점에 대해 고찰하였다.

• 산업기술연구
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• 제22권A호
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• pp.169-176
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• 2002

The purpose of this paper is to investigate for strain measurement of concrete pavement slab at field. The early-age behaviors of concrete pavement were measured using the strain gages. From the static and dynamic wheel loading tests, the outputs from each gages were recorded. The measured data, also, was compared to those from finite element analysis. The static wheel loading tests were performed in twice, and the dynamic wheel loading tests were performed at the speed 10km-50km. The results could be summarized as follows: To embed the strain gage accurately and stably in concrete pavement, a chair and protective box must be used. The protective box must not be affected from the outside vibrating. From the results of early-age stram measurement, it was found that the strain varied at the maximum value of $180{\mu}{\varepsilon}$ From the results of static wheel loading tests, A1, A2 and B gages generally developed a consistent tendency When comparing the results from the measured at field and the calculated by FEM analysis, the data of A1 and B gages were similar to that from theory. The values from the field test were generally higher than that from the theory. From the results of dynamic wheel loading tests, it was known that the measured strain at field became smaller as the truck speed became faster, Indicating the maximum at the range of $12{\sim}13{\mu}{\varepsilon}$.

• 한국환경과학회지
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• 제17권4호
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• pp.397-403
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• 2008

The purpose of this study is to investigate weighted compaction density according to a leading density in truck, a compaction density of solid waste and composition ratios of solid waste fur calculation of a capacity of the landfill sites. The experiments for calculations of in-place density at landfill site have been conducted in S landfill site at B City. The size of vessel for measuring the compaction density was $1m^3(1m{\times}1m{\times}1m)$. The experiment tests have been carried out methods (1 time for bulldozer and 4 times for compactor) that do contain all of specification at the landfill site. Average of the loading density at the landfill site was $0.264\;ton/m^3$ ($0.113{\sim}0.487\;ton/m^3$). When the loading density for each compositions was compared, the composition of the highest average loading density ($0.474\;ton/m^3$) was miscellaneous wastes. The composition of the lowest average loading density ($0.120 ton/m^3$) was general solid waste. The reported results indicated that the compaction density at the landfill site was $0.538\;ton/m^3$, which was calculated with weighted incoming ratios of compositions. The ranges of the density for each composition were from $0.021\;ton/m^3$ to $0.221\;ton/m^3$. When the compaction density for each composition was compared, the composition with the highest average compaction density ($0.221\;ton/m^3$) was miscellaneous wastes. The composition with the lowest average compaction density ($0.021\;ton/m^3$) was general solid wastes.

• 한국산학기술학회논문지
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• 제12권4호
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• pp.1523-1531
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• 2011

본 다축 차량은 험지와 야전에서 높은 이동성 때문에 비포장도로를 주행해야 하는 군용차량으로 사용된다. 특히 군용차량은 군 요구 사항에 의거 기본적으로 60% 경사로에서 안정적인 등판 성능을 지녀야 한다. 따라서 본 논문은 최적 타이어 힘 분배 방법을 통한 6WD/6WS차량의 등판능력 향상을 다루었다. 경사로 등판 시 사용할 최적 타이어 힘 분배 방법을 위하여 운전자로부터, 목표로 하는 종 방향 힘과 횡 방향 힘, 요 모멘트를 계산하였고, 마찰 원이론과 목적함수에 따른 최적화 된 토크가 각 륜에 분배되었다. 알고리즘 성능을 확인하기 위해서, 트럭심 소프트웨어를 이용하여 시뮬레이션 하였고, 비교를 위하여 2대의 차량을 제안하였다. 한 대의 차량은 최적타이어 힘 분배 방법이 적용되었고, 나머지 한 대는 궤도 차량과 같은 균등 힘 분배 방법이 적용되었다. 경사로에서 등판능력은 최적 타이어 힘 분배 방법에 의해서 향상 되어졌다.

• 한국포장학회지
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• 제8권2호
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• pp.1-5
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• 2002

수송포장계열치수를 중심으로 농산물표준출하규격으로 사용되고 있는 농산물 포장용 골판지상자에 대하여 파레트에 대한 적재효율 분석과 화물차적재함 규격에 따른 품목별 적재효율을 분석한 결과는 다음과 같다. 표준형 파레트(T-11)에 대한 각 품목별 적재효율은 $93.6{\sim}99.8%$로 나타났으며 $550mm{\times}366mm$와 $366mm{\times}275mm$의 규격이 99.8%로 가장 높았다. 적재함 규격에 따른 T-11 파레트의 적재효율은 2.5t에서 41.1 56.5%로 낮았으며 11톤(D-7, 적재함규격: $7700mm{\times}2350mm$)의 경우가 93.6%로 가장 높았다. 파레트를 사용하지 않고 운송할 경우 골판지상자 규격이 $550mm{\times}366mm$은 K-4(97%), $488mm{\times}305mm$는 D-8(99.5%), $471mm{\times}314mm$는 H-3(98.3%), $440mm{\times}330mm$은 K-6(99.2%), $412mm{\times}275mm$는 H-9(99.5%)와 H-6(99.4%), $366mm{\times}275mm$는 D-8(97.4%), $320mm{\times}220mm$는 K-6(99.2%), $314mm{\times}235mm$는 D-7(99.5%)와 D-6(99.4%)의 화물차가 가장 적재효율이 높았으며 대체로 8톤과 11톤의 화물차를 이용하는 것이 유리한 것으로 나타났다.