• International Journal of Highway Engineering
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• v.19 no.5
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• pp.153-162
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• 2017

PURPOSES : This study was conducted to analyze the effects arising from extending the duration of nighttime road construction on improving road quality and durability. METHODS : Most previous studies estimating the social cost of various construction conditions did not consider road pavement cooling time as a factor in improving road pavement quality. This study investigated the feasibility of achieving higher road quality and durability by extending the duration of nighttime road construction time extension. For this investigation, the effects of such an extension on traffic conditions were analyzed based on micro-simulation studies and scenario-based cost-benefit analyses, using factors including traffic volume, delay, construction cost, and road pavement cooling time. RESULTS : The results of the traffic simulation studies and cost-benefit analyses indicate that the current road construction method that emphasizes completing nighttime road construction by 6 a.m. reduces pavement life while causing relatively little traffic delay. If the night construction time is instead extended to 2 p.m., road pavement lifetime is increased, reducing road re-construction cost. These savings are greater than the cost of congestion arising from extending the duration of nighttime construction. CONCLUSIONS : The current nighttime construction durations need to be extended in order to efficiently manage roads and reduce road management costs.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11S
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• pp.3684-3693
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• 2000

In this paper, performance of a nonblocking high speed packet switch with switching capacity m which adopts a dynamic priority control function (DPCF) of a threshold- based Bernoulli priority jump (TBPJ) scheme is considered. Each input queue has two separate buffers with different sizes for two classes of traffics, delay-sensitive and loss-sensitive traffics, and adopts a TBPJ scheme that is a general state-dependent Bernoulli scheduling scheme. Under the TBP] scheme, a head packet of the delay-sensitive traffic buffer goes into the loss -sensitive traffic buffer with Hernoulli probability p according to systems states that represent the buffer thresholds and the number of packets waiting for scheduling. Performance analysis shows that TBPJ scheme obtains large performance build-up for the delay-sensitive traffic without performance degradation for the loss-sensitive traffic. In addition to, TBP] scheme shows better performance than that of HOL scheme.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.117-130
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• 1999

In this paper, the performance of data communication function of military radio equipment P-999K is analyzed based on the standard CSMA/CA protocol which is DFWMAC standard protocol done by IEEE802.11 work group. Basic three standard protocols, i.e. Basic CSMA/CA, Stop & Wait ARQ and 4-Way Handshake CSMA/CA protocols are analyzed and compared with each other under the hidden terminal environment. The computer simulation is also done by using SIMSCRIPT II.5 which is popular software tool for an independent processing. The results show that p-persistent(with p=0.3) CSMA scheme is superior to non-persistent CSMA scheme with non-hidden terminal condition, but the performances of both schemes are almost same with hidden terminal situation. And the results of computer simulations are also showed that Basic CSMA/CA protocol is superior to the other protocols when the ratio of hidden terminals is below 10 % of total user population, however, with the above 20% hidden terminals environment and the higher offered traffic conditions the 4-Way Handshake CSMA/CA protocol shows the most superior performance.

• Korean Journal of Health Education and Promotion
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• v.11 no.2
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• pp.18-32
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• 1994

The purpose of this study was to analyze the effectiveness of injury prevention education on elementary school students. We are selected two elementary school in Tejeon, one was intervention school, the other was control school. Surveys were completed before the begining of the interventions in February in 1994 and again after their completion in July 1994. Intervention group was 284 students in pre-test and 218 students in post-test. And control group was 253 students in pre-test and 208 students in post-test. The results of this study was followed. 1. In the general characteristics of subjects studied, sex, mother education, father education, economic status, number of household, and traffic environment were not significant difference between intervention and control group(p>0.05). 2. The contents of injury prevention education that subjects wished to learn, were not significant difference between intervention and control group(p>0.05). Also the mothods of that were significant difference between intervention and control group in pre-test(p<0.05) but not in post-test(p>0.05). 3. Education in knowledge, attitude and practice of injury prevention was slightly effectiveness. Change in attitude of injury prevention was higher than in knowledge and attitude of that we guess that they require a lot of education in the pedestrian prevention. 4. Reative risk between intervention and control group in injury incidence was 1.53 in hospital-care students, and 1.43 in home-care children. Also relative risk of total injury incidence was 1.38, therefore we knew that injury incidence after education was reduced. 5. In the analysis of injury causes, pedestrain injury was remarkably reduced at hospital-care students in two group. At home-care students, two groups were high proportion in play injury. 6. In the analysis of injury places, intervention group was high proportion at near-the house in pre-test(35.4%) and at school in post-test(36.4%). And control group was high at inside-the house in pre-test(31.5%) and at near-the house in post-test(28.2%).

• The Korean Journal of Emergency Medical Services
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• v.9 no.2
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• pp.5-20
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• 2005

Purpose: This study is to examine the relationship between safety awareness and safety accident occurrence with elementary school students. Materials and methods: It selected 10 elementary schools under the supervision of Jeonnam Board of Education and sampled 700 students randomly from 2-3 classes in the 5th and the 6th grade. One preliminary survey was conducted to revise and complement the contents and forms of questionnaire with 70 students of a school from Apr. 1 to 6, 2004 and this study was conducted from Apr. 10 to 30, 2004. Total 700 questionnaires were distributed and 681 were collected (97%) and 602 were used for final analysis except 79 lacking responses. Data collected were analyzed with SPSS statistical program. Results: The average score of safety awareness of subjects by area was high as 2.72 points out of a possible 3. Area showing the highest safety awareness was safety from fire. Girl students had higher safety awareness than boy students. The fifth graders had higher safety awareness than the sixth graders. In safety awareness by the number of siblings, single son or single daughter showed the highest safety awareness. 53.2% of the subjects experienced accident for one year, the frequency of accident was mostly once and most of accidents were occurred at school. Accidents for the last year were higher in boy students, the sixth graders. According to relationship between safety awareness and safety accident, group with lower safety awareness in school safety(P < .022), traffic safety(P < .016), fire safety(P < .019), home safety(P < .007) and accident treatment and first aid(P < .003) had higher safety accidents than that with higher safety awareness. Conclusion: Development of safety education program by grade, that of parents safety education program, field experience and practice with students, teachers and parents and various safety education programs should be substantially and repeatedly accomplished for prevention education of safety accidents. In addition, to prevent and cope with safety accidents, safety education should be reflected on normal education, safety education textbook be developed, special safety education teachers be employed for safety education.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.9
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• pp.2246-2267
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• 2013

BitTorrent is one of the most important applications in the current Internet. Despite of its interest, we still have little knowledge regarding the connectivity properties of real BitTorrent swarms. In this paper we leverage a dataset including the connectivity information of 250 real torrents and more than 150k peers to carefully study the connectivity properties of peers. The main topology parameters of the studied swarms suggest that they are significantly less resilient than random graphs. The analysis of the peer level connectivity properties reveals that peers continuously change more than half of their neighbours. Furthermore, we also find that a leecher typically keeps stable connections with a handful of neighbours with which it exchanges most of its traffic whereas seeders do not establish long-term connections with any peer so that they can homogeneously distribute chunks among leechers. Finally, we have discovered that a significant portion of the studied peers (45%) have an important locality-biased neighbourhood composition.

• Journal of Acupuncture Research
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• v.24 no.6
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• pp.37-44
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• 2007

Objectives : The purpose of this study is to find out the effects of Chuna treatment on neck pain caused by traffic accidents. Methods : The 10 patients were divided into 2 groups, with Group A treated with Acupuncture and Chuna, while group B was treated with Acupuncture only. We measured the Visual Analog Scale(VAS), Pain Disability Index(PDI) and Pressure Pain Thresholds before and after treatment in each group. The statistical analysis was performed by using a Mann-Whitney U test and Wilcoxon signed rank test. Results : 1. Group A showed significant improvements in VAS, PDI and Pressure Pain Thresholds(p<0.05). 2. Group B was significantly improved in VAS(p<0.05). However, there was no statistical significance in PDI and Pressure Pain Thresholds(p>0.05). 3. There was no statistical significance between Group A and Group B before and after treatment. Conclusions : These results imply that Chuna treatment with Acupuncture would beeffective and useful on the neck pain caused by traffic accidents.

• The Korean Journal of Emergency Medical Services
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• v.1 no.1
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• pp.100-111
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• 1997

This is the first Korea study to evaluate the effects od the safety of ambulance driving and the occurrence of ambulance traffic accidents and to provide basic informaion for the description of various factors to reduce the ambulance traffic accidents. The major insturment of this study were Krean Self-Analysis Driver Opinionnaire. Questionnaire contains 8 items which measure driver's opinions or attitudes : driving courtesy, emotion, traffic law, speed, vehicle conditions, the use of drugs, high-risk behaviors, and human factors. To take the analysis of data, the total of 350 divers were investigated ambulance divers and others in Taejon City and others (6 City) from 1996. 1. July to 1996. 31. July. The data were analyzed by the descriptive statistics and the logistic regression - path analysis - with SPSS and SAS package program. The result are as follows : 1. There was desirable attitude group(16.2%) and undesirable attitude group(17.6%) on safety ambulance driving. 2. It have suggested that risk factors of ambulance traffic accidents much affected with emotion and speed control on safety ambulance driving < Y(Accdient) = -2.64 + 0.57 $X_1$ (Emotion Control) + 0.30 $X_2$(Seed control) + E > and motor traffic acident much affected with emotion control and high-risk behavior on safety driving < Y(Accident) = -1.11 + 0.33 $X_1$(Emotion Control) + 0.29 $X_2$(High-risk Behvior) + E > 4. The primary emphassis of ambulance drivers was make us realized that improthatnt factors on safety ambulance driving were 1)making way for emergent ambulance, 2)driver's career, 3)The ability of emergency medical technics, and the knowledge or under standing of ambulance way difficut(or easy) of accdess. 5. Almost 96.6% of respondents have agreed to necessity of emergency medical technics for ambulance drivers. 6. Almost 94.6% of respondents have consented to necessity of emergtency medical technicians for ambulance driving. 7. It have suggested that the proportion of traffic accident proportion by desitable attitude group(16.7%) was much less than that of undesirable attitude group(30.8%) on safety ambulance driving(P < 0.05)/Ps) Accidents are unplanned, unforesen incidents which can lead to harmful or unfortunate outcomes, Collisons are not accidents, since the basic cause of the majority of collisons invovles high-risk human behavior. Although there are many factors which contribute to accident causation, four basic factors seem to predominate in most traffic related situations. These four factors include: the human factor, the vehicle factor, the environmental factors and destination factor(Peto G. et al. 1995).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.9
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• pp.1166-1175
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• 2021

We investigate the current situation and development trend of domestic smart city and emergency vehicle priority signal control system analyzing the existing effectiveness of 1) emergency vehicle priority signal control system and 2) control emergency vehicle priority signal, based on domestic and foreign prior research for signal control system security. The effectiveness of time reduction was analyzed through actual application and test operation to emergency vehicles after establishing the system. In addition, for security management and stable service of real-time signal system control we propose improvement for the technical control items of the ISMS-P certification system to secure golden time to protect citizens' precious lives and property in case of emergency by classifying and mapping the existing ISMS-P certification system and the Korea Internet & Security Agency's cyber security guide according to the items of security threats.

• The Journal of the Acoustical Society of Korea
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• v.19 no.8
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• pp.3-11
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• 2000

This paper considers the performance of a dynamic priority control function (DPCF) of a threshold-based Bernoulli priority jump (TBPJ) scheme. Loss-sensitive and delay-sensitive traffics are applied to a system with a TBPJ scheme that is a general state-dependent Bernoulli scheduling scheme. Loss-sensitive and delay-sensitive traffics represent sound and data, respectively. Under the TBPJ scheme, the first packet of the loss-sensitive traffic buffer goes into the delay-sensitive traffic buffer with Bernoulli probability p according to system states which represent the buffer thresholds and the number of packets waiting for scheduling. Performance analysis shows that TBPJ scheme obtains large performance build-up for the delay-sensitive traffic without performance degradation for the loss-sensitive traffic. TBPJ scheme shows also better performance than that of HOL scheme.