• Title/Summary/Keyword: Race Condition

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Effects of race conditions on racing injury in Thoroughbred horses (경주환경이 경주사고에 미치는 영향)

  • Yang, Young-jin;Cho, Gil-jae;Yang, Jae-Huek;Nam, Tchi-chou
    • Korean Journal of Veterinary Research
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    • v.41 no.2
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    • pp.261-267
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    • 2001
  • This research was conducted to investigate the effects of race conditions on racing injury in Thoroughbred(TB) horses. A total 335 horses were investigated the relationship between race conditions and racing injuries. The main environmental factors of racing injuries were spring season, rainy weather and sloppy racetrack. In the race types, high incidence of racing injury was found in special weigh, stakes, middle class and long length race. This results suggest that the racing injury can be effected to both individual body condition and various racetrack conditions.

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Detecting TOCTOU Race Condition on UNIX Kernel Based File System through Binary Analysis (바이너리 분석을 통한 UNIX 커널 기반 File System의 TOCTOU Race Condition 탐지)

  • Lee, SeokWon;Jin, Wen-Hui;Oh, Heekuck
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.31 no.4
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    • pp.701-713
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    • 2021
  • Race Condition is a vulnerability in which two or more processes input or manipulate a common resource at the same time, resulting in unintended results. This vulnerability can lead to problems such as denial of service, elevation of privilege. When a vulnerability occurs in software, the relevant information is documented, but often the cause of the vulnerability or the source code is not disclosed. In this case, analysis at the binary level is necessary to detect the vulnerability. This paper aims to detect the Time-Of-Check Time-Of-Use (TOCTOU) Race Condition vulnerability of UNIX kernel-based File System at the binary level. So far, various detection techniques of static/dynamic analysis techniques have been studied for the vulnerability. Existing vulnerability detection tools using static analysis detect through source code analysis, and there are currently few studies conducted at the binary level. In this paper, we propose a method for detecting TOCTOU Race Condition in File System based on Control Flow Graph and Call Graph through Binary Analysis Platform (BAP), a binary static analysis tool.

A Study on Grinding for Inner Race (내륜 연삭에 관한 연구)

  • Kim, Woo-Kang;Kim, Geon-Hee
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.6
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    • pp.46-49
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    • 2011
  • The grinding is a popular process for studying constant velocity joint and process in automobile industry. In this study, The study gives the data of wheel type and grinding of inner race is developed. As a result I obtained the data of grinding conditions makes good surface roughness get a grinding conditions. The grinding characteristics and conditions of inner race were investigated with respect to grinding feed, cutting depth, grinding time. The results were suddenly increased and the detailed surfaces were extremely obtained. Grinding condition was big more affected by grinding time, grinding speed and grinding depth.

Incidence of exercise-associated hyponatremia during a high-altitude 161-km ultramarathon

  • Khodaee, Morteza;Saeedi, Anahita;Harris-Spinks, Christine;Hew-Butler, Tamara
    • Korean Journal of Exercise Nutrition
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    • v.25 no.3
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    • pp.16-22
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    • 2021
  • [Purpose] Exercise-associated hyponatremia (EAH) is a well-known condition among endurance athletes at low altitudes. The incidence of EAH during ultramarathons at high altitudes warrants further investigation. This prospective observational study was conducted on the participants of the Leadville Trail 100 run, a 161-km race held at a high altitude (2,800 m-3,840 m). [Methods] Venous blood samples were collected before and immediately after the race. The participants completed an electronic survey after the race. Our main outcome measure was the post-race serum sodium ([Na+]) level. [Results] Of the 672 athletes who started the race, 351 (52%) successfully completed the event within the 30-hour cut-off. Post-race blood samples were collected from 84 runners (66 finishers). Both pre- and post-race blood samples were collected from 37 participants. Twenty percent of the post-race participants had EAH. Only one post-race participant had a [Na+] level of <130 mmol/L. All participants with EAH were asymptomatic. One participant had an abnormal pre-race [Na+] level (134 mmol/L). Female participants had a significantly higher rate of EAH than male participants (40% vs. 16%; p=0.039). Age, body mass index, weight changes, race completion status, nonsteroidal anti-inflammatory drug use, and urine specific gravity were not associated with the development of EAH. Lower postrace [Na+] levels were associated with higher serum creatine kinase values (R2=0.1, p<0.005). [Conclusion] High altitude (3,840 m peak) does not appear to enhance the incidence of EAH after an ultramarathon footrace. This suggests that ambient temperature (low temperatures reduce risk), sex (female predilection), endurance running, and overhydration are more prominent risk factors for EAH than high altitude.

Detection and Classification of Bearing Flaking Defects by Using Kullback Discrimination Information (KDI)

  • Kim, Tae-Gu;Takabumi Fukuda;Hisaji Shimizu
    • International Journal of Safety
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    • v.1 no.1
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    • pp.28-35
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    • 2002
  • Kullback Discrimination Information (KDI) is one of the pattern recognition methods. KDI defined as a measure of the mutual dissimilarity computed between two time series was studied for detection and classification of bearing flaking on outer-race and inner-races. To model the damages, the bearings in normal condition, outer-race flaking condition and inner-races flaking condition were provided. The vibration sensor was attached by the bearing housing. This produced the total 25 pieces of data each condition, and we chose the standard data and measure of distance between standard and tested data. It is difficult to detect the flaking because similar pulses come out when balls pass the defection point. The detection and classification method for inner and outer races are defected by KDI and nearest neighbor classification rule is proposed and its high performance is also shown.

Validation of Contact Modeling Technique for Dynamic Analysis of Roller Bearing System (롤러 베어링의 동역학 해석을 위한 접촉 모델링 기법의 검증)

  • Jung, Eun-Kyo;Choi, Jin-Hwan;Rhim, Sung-Soo;Ryu, Han-Sik
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.4
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    • pp.115-123
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    • 2007
  • In this paper, an analytical model is developed to describe the dynamic characteristics of a roller bearing. In order to obtain accurate dynamic response of roller bearing, each roller is modeled as a rigid body, which has radial and axial movement and rotational constraints. Beam element between outer race segments is used to consider flexibility of outer race. Beam deflection is calculated from beam forces and used for contact between roller and outer race. The efficient contact search kinematics and algorithms in the context of the compliance contact model are implemented to detect the interactions between roller and race for the sake of speedy and robust solutions. The numerical results are validated with another analysis results which are calculated using waviness condition. Increasing rollers, dynamic responses are compared with each other. In order to confirm dynamic behavior and nonlinear characteristic of roller bearing, Poincare map is used.

Condition Monitoring of Low Speed Slewing Bearings Based on Ensemble Empirical Mode Decomposition Method

  • Caesarendra, W.;Park, J.H.;Choi, B.H.;Kosasih, P.B.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.10a
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    • pp.388-393
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    • 2012
  • Vibration condition monitoring at low rotational speeds is still a challenge. Acoustic emission (AE) is the most used technique when dealing with low speed bearings. At low rotational speeds, the energy induced from surface contact between raceway and rolling elements is very weak and sometimes buried by interference frequencies. This kind of issue is difficult to solve using vibration monitoring. Therefore some researchers utilize artificial damage on inner race or outer race to simplify the case. This paper presents vibration signal analysis of low speed slewing bearings running at a low rotational speed of 15 rpm. The natural damage data from industrial practice is used. The fault frequencies of bearings are difficult to identify using a power spectrum. Therefore the relatively improved method of empirical mode decomposition (EMD), ensemble EMD (EEMD) is employed. The result is can detect the fault frequencies when the FFT fail to do it.

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A Labeling Scheme for Efficient On-the-fly Detection of Race Conditions in Parallel Programs (병렬프로그램의 경합조건을 수행 중에 효율적으로 탐지하기 위한 레이블링 기법)

  • Park, So-Hee;Woo, Jong-Jung;Bae, Jong-Min;Jun, Yong-Kee
    • The KIPS Transactions:PartA
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    • v.9A no.4
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    • pp.525-534
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    • 2002
  • Race conditions, races in short, need to be detected for debugging parallel programs, because the races result in unintended non-deterministic executions. To detect the races in an execution of program, previous techniques use a centralized data structure which may incur serious bottleneck in generating concurrency information, or show inefficient time complexity which depends on the degree of nested parallelism in comparing any two of them. We propose a new labeling scheme in this paper, which is scalable in generating the concurrency information without bottleneck by using private data structure, and improves time complexity into constant in checking concurrency. The scalability and time efficiency therfore makes on-the-fly race detection efficient not only for programs with either shared-memory or message-passing, but also for programs with mixed model of the two.

A Study on the Vibration Analysis of Multi-components Damaged Ball Bearing under Radial Load (반경하중을 받는 결함 볼베어링의 진동해석에 관한 연구)

  • 김영주;전효중
    • Journal of Advanced Marine Engineering and Technology
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    • v.12 no.2
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    • pp.35-45
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    • 1988
  • In this paper an experimental review of condition monitoring method using time domain vibration signals and statically measured wave forms of a multi-components damaged ball bearing is presented first time. Many investigators studied already about vibration characteristics of a single point damaged ball bearing but they did not make efforts to verify vibration phenomena of a multi-components damaged one. Even in case of a tripple components damaged (i.e, outer race, inner race and rolling element) one, the high frequency resonance technique (HERT) and the displacement time domain technique can be also used for its fault detection. According to experimental results undertaken a static displacement measuring method, the defect locations of components can be proposed confidently with simple calculation of the rotating angles of each component.

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Features of Housing and Living Pattern in the North Eastern Regions of China - Centered on the Daor living in the Heilongjiang - (중국(中國) 동북부(東北部) 제민족(諸民族)의 주거(住居) 및 주생활(住生活) 특성 -흑룡강성(黑龍江星)과 내몽고자치구(內蒙古自治區)에 거주하는 다워얼(達斡爾)족을 중심으로-)

  • Shin, Soo-Young;Yoon, Chung-Sook
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2003.11a
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    • pp.259-264
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    • 2003
  • This study aims to understand the architectural characteristics and living pattern of the Daor and to make a comparative study with the Han race. This research inquired into the background of the Daor and surveyed the present condition of traditional houses. As a result of this study, the features of Daor's traditional house is synthesized as follows. 1) The arrangement of village is in a row facing south. The site plan and exterior shape is like as the Manchurian race. 2) Making west window and creating a bright atmosphere is the unique architectural style. 3) Viewed from spatial layout and function, Daor's has more remarkable difference from Han's. That is to say, the room equipped with Kang is daily space and kitchen is just space for cooking in contrast with the Han.

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