• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.561-568
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• 2021

In this study, in order to observe the change in the amount of Tire and Road Wear Particles and the ratio of tire components in it according to the tire wear resistance performance, carried out the evaluation by varying the vulcanization reaction design of the tire tread rubber. In addition, in order to improve the reliability of the evaluation of Tire and Road Wear Particles, the evaluation was performed indoor laboratory test equipment that simulates the condition on real driving to exclude various environmental influences including minerals, driver's habits, road surface, weather, tire structure and pattern designs. After the evaluation in closed space, it is estimated that the amount of collected Tire and Road Wear Particles is 84% compared to 100% of the tire and road wear loss weight, of which 96.4~97.7% was around the road and 2.3~3.6% was in the air. As a result of analy sis of the collected Tire and Road Wear particles, the tire component existed 63~75% in the Tire and Road Wear Particles depending on the wear resistance performance of the tire.

• Korean Journal of Materials Research
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• v.5 no.3
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• pp.316-323
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• 1995

페놀수지 결합재에 PAN섬유(PF), PAN계 탄소섬유(CF) 그리고 아라미드 섬유(AF)를 보강재로 사용하여 단일섬유 보강복합재를 제조하였으며 이들 섬유를 각각 두 종류씩 혼성하여 혼성섬유 보강복합재를 제조하였다. 각 보강복합재를 섬유의 보강분율에 따른 마찰 및 마모특성을 시험하였다. CF 보강복합재(CFRP)가 마찰계수와 마모량이 가장 낮게 나타났으며, PF 보강복합재(PFRP)는 가장 높은 마찰계수와 마모량을 나타내었다. PF에 CF나 AF를 보강한 혼성복합재의 경우 마찰계수가 0.311~0.328로 혼성비에 따라서는 큰 차이를 보이지 않은 반면, PF의 보강분율이 증가할수록 마모량은 증가하였다. CF와 AF를 보강한 혼성복합재의 마찰계수는 0.264~0.309로 가장 낮게 나타났고, AF의 보강분율이 증가함에 따라 마찰계수는 증가하는 양상을 나타내었으며, 가장 적은 마모량과 함께 안정된 마모형태를 보였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.3
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• pp.488-492
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• 2009

This paper have been analyzed specific wear characteristics of various base oils used in the automobile engine by experimental study. Specific wear amount has been calculated by the measured normal force and friction force under various speed operating conditions, such as, viscosities and temperatures. It have been verified that the specific wear characteristics relation of the base oil used in a engine oil is related to the various operating conditions.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.346-349
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• 2015

Generally, in order to verify the degree of tire wear or abnormal wear, a driver or an auto mechanic checks the degree of tire wear and the existence of tire abnormality, directly with the naked eye or by way of using a gauge equipment. In case of such verification, individual subjective judgments may be involved or a driver may suffer heavy burdens to expend the time and cost for using the wheel alignment equipment. Therefore, this thesis will use a number of laser sensors to check the existence of abnormal wear and the degree of wear on each tire and develop a system checking the sides of tires to receive the tire information, so that subjective judgments may be overcome and objective and accurate judgments may be rendered.

• Proceedings of the Korean Society of Computer Information Conference
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• 2016.01a
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• pp.5-7
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• 2016

본 논문에서는 블록 생성 번호를 활용한 동적 마모도 평준화 기법을 제안한다. 지금까지 제안된 동적 마모도 평준화 기법들은 콜드 블록을 판별하기 위해 경과 시간을 사용하고 있다. 하지만 저장장치의 데이터 접근은 일정한 시간 간격으로 이루어지는 것이 아니기 때문에 이와 같은 경과 시간을 사용하는 방식은 데이터에 대한 블록 접근 정보가 왜곡될 수 있는 단점이 있다. 이러한 단점을 해결하기 위해, 본 논문에서 제안하는 기법은 블록을 할당할 때 블록 순차 번호를 테이블에 저장하고 이를 이용하여 블록의 접근 빈도를 판별한다. 실험에서 제한하는 기법은 기존의 CB, CAT 기법과 비교하여 최대 11% 수명이 향상됨을 확인하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.139-144
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• 2019

For recent decades, Non-volatile Memory (NVM) technologies have been drawing a high attention both in industry and academia due to its high density and short latency comparable to that of DRAM. However, NVM devices has write endurance problem and thus the current data structures that have been built around DRAM-specific features including unlimited program cycles is inadequate for NVM, reducing the device lifetime significantly. In this paper, we revisit a red-black tree extensively adopted for data indexing across a wide range of applications, and make it to better fit for NVM. Specifically, we observe that the conventional red-black tree wears out the specific location of memory because of its rebalancing operation to ensure fast access time over a whole dataset. However, this rebalancing operation frequently updates the long-lived nodes, which leads to the skewed wear out across the NVM cells. To resolve this problem, we present a new swapping wear-leveling red-black tree that periodically moves data in the worn-out node into the young node. The performance study with real-world traces demonstrates the proposed red-black tree reduces the standard deviation of the write count across nodes by up to 12.5%.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.5
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• pp.469-474
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• 2014

The high temperature gas-cooled reactor (HTR-10) is designed to produce electricity and hydrogen. Graphite is used as reflector, support structures, and a moderator in reactor core; it has good resistance to neutron and is a suitable material at high temperatures. Friction is generated in the graphite structures for the core reflector, support structures, and moderator because of vibration from the HTR-10 fuel cycle flow. In this study, the wear characteristics of the isotropic graphite IG-110 used in HTR-10 were evaluated. The reciprocating wear test was carried out for graphite against graphite. The effects of changes in the contact load and sliding speeds at room temperature and $400^{\circ}C$ on the coefficient of friction and specific wear rate were evaluated. The wear behavior of graphite IG-110 was evaluated based on the wear surfaces.

• Tunnel and Underground Space
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• v.34 no.2
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• pp.143-153
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• 2024

Tunnel Boring Machine (TBM) method is a tunnel excavation method that produces lower levels of noise and vibration during excavation compared to drilling and blasting methods, and it offers higher stability. It is increasingly being applied to tunnel projects worldwide. The disc cutter is an excavation tool mounted on the cutterhead of a TBM, which constantly interacts with the ground at the tunnel face, inevitably leading to wear. In this study quantitatively predicted disc cutter wear using geological conditions, TBM operational parameters, and machine learning algorithms. Among the input variables for predicting disc cutter wear, the Uniaxial Compressive Strength (UCS) is considerably limited compared to machine and wear data, so the UCS estimation for the entire section was first conducted using TBM machine data, and then the prediction of the Coefficient of Wearing rate(CW) was performed with the completed data. Comparing the performance of CW prediction models, the XGBoost model showed the highest performance, and SHapley Additive exPlanation (SHAP) analysis was conducted to interpret the complex prediction model.

• International Journal of Highway Engineering
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• v.9 no.4
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• pp.117-127
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• 2007

The exposed aggregate PCC(EAP) pavements have been successfully used in Europe and Japan as low-noise pavements. Coarse aggregate are exposed on the pavement surface texture of EAP by removing mortar of surface. The pavement surface texture should maintain not only low-noise characteristic but also adequate skid resistance level during the performance period. Skid resistance decreased with wearing and polishing of tire and pavement surface due to the repetition of tire-pavement contact. Since the tires mainly contact the exposed coarse aggregate, the shape and rock type of coarse aggregate significantly influence wearing and polishing of EAP pavements. The test for resistance to abrasion coarse aggregate by use of the Los Angeles machine(KS F 2508) and the method of test for resistance to abrasion coarse aggregate by use of the Accelerated Polishing Machine(ASTM D 3319-90) are generally used to evaluate polishing characteristics of aggregate. In this study, polishing of coarse aggregate of different five rock types were evaluated by KS F 2508(LA abrasion test) and ASTM D 3319-90(PSV method). The results of LA abrasion test and PSV method were contrary to each other. Since LA abrasion test is estimated the quantity of abrasion by the impact of aggregate, it may not be adequate to evaluate the polishing of aggregate by the repetition of tire. In the case of PSV method, the resistance of polishing is estimated the skid resistance variation of polished aggregate after repetition of tire. The PSV method is adequate for the evaluation on polishing of coarse aggregate. From the test results of PSV method, it was founded that rock type, specific gravity, coarse aggregate angularity, flat or elongated particles in coarse aggregate are significant to the resistance characteristic of coarse aggregate.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.12
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• pp.1204-1208
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• 2010

In this paper, we propose a flash memory wear-leveling scheme that makes use of meta-data storage region as a regulation pool. By concentrating program and erase operations on the blocks with lower erase counts in the regulation pool, the proposed scheme achieve an even wear-leveling in a simple and efficient way. Experiments with an implementation of the proposed scheme in RS-FTL showed that the erase count deviation is reduced by around 40% through the erase count regulation.