• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.1879-1887
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• 2013

To investigate the level of genotoxicity over Bangkok atmosphere, $PM_{10}$ samples were collected at the Klongchan Housing Authority (KHA), Nonsree High School (NHS), Watsing High School (WHS), Electricity Generating Authority of Thailand (EGAT), Chokchai 4 Police Station (CPS), Dindaeng Housing Authority (DHA) and Badindecha High School (BHS). For all monitoring stations, each sample covered a period of 24 hours taken at a normal weekday every month from January-December 2006 forming a database of 84 individual air samples (i.e. $12{\times}7=84$). Atmospheric concentrations of low molecular weight PAHs (i.e. phenanthrene, anthracene, pyrene and fluoranthene) were measured in $PM_{10}$ at seven observatory sites operated by the pollution control department of Thailand (PCD). The mutagenicity of extracts of the samples was compared in Salmonella according to standard Ames test method. The dependence of the effects on sampling time and on sampling location was investigated with the aid of a calculation of mutagenic index (MI). This MI was used to estimate the increase in mutagenicity above background levels (i.e. negative control) at the seven monitoring sites in urban area of Bangkok due to anthropogenic emissions within that area. Applications of the AMES method showed that the average MI of $PM_{10}$ collected at all sampling sites were $1.37{\pm}0.10$ (TA98; +S9), $1.24{\pm}0.08$ (TA98; -S9), $1.45{\pm}0.10$ (TA100; +S9) and $1.30{\pm}0.09$ (TA100; -S9) with relatively less variations. Analytical results reconfirm that the particulate PAH concentrations measured at PCD air quality monitoring stations are moderately low in comparison with previous results observed in other countries. In addition, the concept of incremental lifetime particulate matter exposure (ILPE) was employed to investigate the potential risks of exposure to particulate PAHs in Bangkok atmosphere.

• Korean Security Journal
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• no.39
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• pp.387-411
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• 2014

School violence is now considered not only as a problem for a victim and a offender themselves, but also as a social problem that requires responsibilities of school, home, society, and even nation. Crimes and risk factors are various inside and outside of school. In terms of solving those problems, this study examines the actual condition of school violence among students. In addition, it is considered what efforts are conducted by police to establish a safe school environment and the problems that derive from it. Futhermore, this study aims to discuss the ways of using the private security with regard to dealing with school violence. In this society, the expectation of security service from the police is increased as time passed. However, police has limited resources, thus it is beyond their practice. Policing has changed from being monopolized by government to cooperating with various security agents. Community is not considered as the subject for enforcing the law anymore, but as the cooperator for effective policing. With regard to the limitation of police force, using the private security is an effective alternative. Therefore, it is required that private security should be assigned legal authority and shared information with schools in order to patrol the blind spot. Finally, school violence prevention efforts should be conducted by applying physical and electronic security.

• Journal of Power System Engineering
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• v.16 no.3
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• pp.64-68
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• 2012

Because the magnetic bearing supports levitating body without contact, wear, noise and vibration are very small comparing with mechanical bearings, it is very useful to high revolution machinery. In general, the magnetic attractive force function that is proportional to square of control current(x), and inversely proportional to square of an air gap(i) has been widely used. This paper proposed the new magnetic attractive force function that is proportional to cube of the control current, and inversely proportional to square of the air gap. The function was optimized to minimize the cost function that is the percentage of deviation about the change of a proportional constant(k), using the experimental data, ie, control currents and air gaps.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.480-483
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• 2004

This paper, we present the evaluation of outage probability on the SNR under the overlapped carrier allocation scheme in the reverse link with imperfect power control of a cellular CDMA system, which is base on using Gaussian approximation. In numerical results, the band limited pulse generated by square-root of raised consin pulse shaping filters (SRRC) of the transmitted signal is investigated and compared in conventional FD/CDMA and OC-CDMA of the outage probability. It will be also show that the outage probability can be improved by overlapping of carriers. We use error statistics to model the intra-cell interference and evaluate the impact of different mobiles velocity and number of resolvable paths on the system performance.

• Journal of Digital Convergence
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• v.7 no.3
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• pp.1-11
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• 2009

In this paper I examined economies and implications of "Net Neutrality" and Internet Freedom. It is argued that mandating Net Neutrality would be likely to reduce economic welfare. Instead, the government should focus on creating competition in the broadband market by liberalizing more spectrum and reducing entry barriers created by certain local regulations. In cases where a broadband provider can exercise market power the government should use its antitrust enforcement authority to police anti-competition behavior. To assure Net Neutrality, it is needed to make sure of fair competition and to facilitate flexible prices. Especially it is needed to invest consistently to the sector of Network.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.546-548
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• 2003

The expanded waste glass material is one of the recycling materials. We investigated whether the expanded waste glass material is useful as planting basis and effective as heat insulation. We examined the difference of the materials by using vegetation index and temperature. The combination of the improved soils and the improved glasses marked higher vegetation index than other mixture materials. Moreover, this combination material is excellent than other ones to heat insulation. Therefore, it suggests that the expanded waste glass material has high potential to be used as a material for planting basis.

• Journal of Power System Engineering
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• v.17 no.4
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• pp.139-146
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• 2013

Because the magnetic bearing supports levitating body without contact, wear, noise and vibration, it is very useful to high revolution machinery. In this paper we selected ATmega 128, a less expensive and widely used micro controller, for control the magnetic bearing system. And we selected the sampling time and the control gain of PID controller through trial-and-error. The control program of the one board controller utilized lookup table to reduce calculation time, and bit shifting for the integer calculation in instead of floating point calculation. As the results, the controller carried out relatively high speed PID control on sampling time 0.25 ms. At last the rotation test for the magnetic bearing system was carried out by 3 phase induction motor and air turbine.

• Journal of Navigation and Port Research
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• v.48 no.2
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• pp.88-96
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• 2024

This study examined challenges posed by two ferry routes, namely, Likoni and Mtongwe crossings, in the Mombasa Channel and their impact on navigational safety. Utilizing the Environmental Stress (ES) model, this study analyzed current ship traffic and assessed stress levels imposed by ferry crossing traffic on navigators. ES values revealed significant stress at these ferry crossings attributed to varying transit speeds. Standardizing transit speeds at two ferry passages can reduce high stress levels, presenting a viable solution. Furthermore, the IWRAP Mk2 simulation underscores crossing collisions as a significant concern, particularly at Likoni and Mtongwe crossings, due to increased ferry traffic. This research offers valuable insights for stakeholders, such as the Kenya Ports Authority (KPA), to develop targeted safety measures and enhance the flow of ship traffic in the channel.

• Journal of the Society of Disaster Information
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• v.10 no.4
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• pp.559-565
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• 2014

This study provides the basic data for using the connections of Interpol to combat supranational crimes, reflecting domestic and foreign situations, and I'll summarize the countermeasures as follows through the results of this study. First of all, it is necessary to build up the international cooperative system which shares information and technology between nations, through the network formation of Asianpol. Second, a policy of Interpol which maximizes the foreign agents and resident officers in Korea needs to be established. Third, governmental policies and legal measures such as criminal extradition must be available to help the criminal investigations of Interpol quickly and positively. Fourth, there has to be the expansion of budget for securing professional investigators and supporting Interpol to fight supranational crimes by the authority of the government.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.198-206
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• 2014

According to the statistics of the National Police Agency, red light running (RLR) crashes represent a significant safety issue throughout Korea. This study deals with the RLR crashes occurred at signalized intersections in Cheongju. The objectives of this study are to comparatively analyze the characteristics of between RLR crashes and the Non-RLR crashes, and to find out factors using a Binary Logistic Regression(BLR) model. In pursuing the above, the study gives particular attentions to testing the differences between the above two groups with the data of 2,246 RLR/ 3,884 Non-RLR crashes (2007-2011). The main results are as follows. First, many RLR crashes were occurred in the nighttime and in going straight. Second, the difference between RLR and Non-RLR crashes were clearly defined by crash type, maneuver of vehicle before crash, age of driver (30s, 50s), alcohol use and accident pattern. Finally, a statistically significant model (Hosmer and Lemeshow test : 7.052, p-value : 0.531) was developed through the BLR model.