• International Journal of Highway Engineering
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• v.18 no.4
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• pp.69-75
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• 2016

PURPOSES : In this study, we evaluated changes in the retroreflectivity and luminance of phosphorescent road line markings with changes in glass beads and line marking thickness. METHODS : The color of line markings affects their retroreflectivity. Using a chromaticity test, we conducted the analysis of whether phosphorescent road line markings adhered to the "KS M 6080" standard. Then, we measured the dry retroreflectivity and wet retroreflectivity for various glass bead refractive indices. We conducted wet retroreflectivity test using the EN 1436 standard as the basis. We also conducted luminance tests for different glass bead refractive indices and line marking thicknesses. RESULTS : 1. Phosphorescent road line markings specimens satisfied the "KS M 6080" standard. 2. In dry retroreflectivity test, phosphorescent road line markings sprayed with glass beads satisfied the national police agency standard ($240mcd/(m^2{\cdot}Lux)$). Wet retroreflectivity test results showed that except for one type of No.1 glass beads, phosphorescent road line markings specimens sprayed with glass beads of one type of No.3 and two types of No.1 satisfied the national police agency standard ($100mcd/(m^2{\cdot}Lux)$). 3. Phosphorescent road line markings had higher retroreflectivity than non-phosphorescent road line markings in the dry condition. 4. Phosphorescent road line markings sprayed with glass beads demonstrated improved luminance. Luminance increased with higher glass bead refractive index and with increased line marking thickness. However, when the thickness crossed a certain threshold, phosphorescence ceased to increase; this is a characteristic of the phosphorescence phenomenon. CONCLUSIONS : Visibility across short distances can be ensured when phosphorescent road line markings are sprayed with glass beads, because of the retroreflection phenomenon. It is also possible to ensure far visibility using phosphorescent road line markings.

• 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 the Korean Society of Fisheries and Ocean Technology
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• v.53 no.2
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• pp.177-186
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• 2017

This study is intended to provide navigator with specific information necessary to assist in the avoidance of collision and in operation of ships to evaluate the maneuverability of research vessel Jera. Authors carried out full-scale sea trials for turning test, zig-zag test, and spiral test at actual sea-going condition, which were performed on starboard and port sides with 10-20 rudder angle at service speed of 10 knots. The turning circle was much different at both of the turning of port and starboard which was longer at the starboard than at the port. In the zig-zag test results, the port and starboard was $10^{\circ}$ the first and second overshoot angles were $6.0^{\circ}$, $5.8^{\circ}$ and $6.3^{\circ}$, $7.1^{\circ}$ respectively and the first overshoot angles were $16.4^{\circ}$, $17.6^{\circ}$ when using $20^{\circ}$. Her maneuverability index T and N can be easily determined by using an analogue computer with the data obtained from the zig-zag tests where K is a constant representing the turning ability and T is a constant representing her quick response. In the zig-zag tests under $10^{\circ}$ or $20^{\circ}$ at rudder angle, the value K is 0.149. 0.123 sec- and T is 11.853 and 6.193 sec and angular velocity is $0.937^{\circ}/sec$ and $1.636^{\circ}/sec$. In the spiral test, the loop width was unstable at $+0.51^{\circ}$ and $-1.19^{\circ}$ around the midship of rudder, but the tangent line at $0^{\circ}$ was close to vertical. From the sea trial results, we found that she did comply with the present criterion in the standards of maneuverability of IMO.

• Sleep Medicine and Psychophysiology
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• v.17 no.1
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• pp.28-33
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• 2010

Objectives: Working at other times than the regular day shift has been reported to be a stressor associated with health consequences and mental disorders as well as disturbance of sleep. In current study, we aimed at investigating the relationship between work schedule, sleep quality and depression among police officers. Methods: Eleven hundreds and forty five police officers (male: 1040, female: 105) completed questionnaires of basic socio-demographic data, Pittsburgh Sleep Quality Index (PSQI), Korean Scale of Occupational Stress (KOSS), Impact of Event Scale - Revised (IES-R) and Center for Epidemiologic Study-Depression (CES-D). Results: After controlling for age, sex and educational level, score of CES-D was correlated positively with the score of KOSS, PSQI and IES-R on partial correlation analysis (r=-0.077; p=0.009, r=0.262; p<0.000 and r=0.421, p<0.000, respectively). Logistic regression analysis revealed that female sex, age, the score of KOSS and IES-R and schedule of rotating shift work predicted higher score than 16 score of CES-D significantly in total subjects (p=0.023, p=0.015, p=0.000, p=0.000 and p=0.022, respectively). Conclusion: Current result suggested that not only female sex, age, higher occupational stress and impact of event scale but also rotating shift work schedule might be related to depression among police officers.

• Journal of Korean Society of Rural Planning
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• v.22 no.2
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• pp.121-129
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• 2016

A disaster can be defined in many ways based on perspectives, in addition, its types are able to classify differently by various standards. Considering the different perspectives, the disaster can be occurred by natural phenomenon that is like typhoon, earthquake, flood, and drought, and by the accident that is like collapse of facilities, traffic accidents, and environmental pollution, etc. Into the modern society, moreover, the disaster includes the damages by diffusion of epidemic and infectious disease in domestic animals. The disaster was defined by natural and man-made hazards in the past. As societies grew with changes of paradigm, social factors have been included in the concept of the disaster according to new types unexpected by new disease and scientific technology. Change the concept of social disasters, Ministry of Public Safety and Security (MPSS) has provided the regional safety index, which measures the safety level of a local government. However, this regional safety index has some limitation to use because this index provides the information for city unit which is a unit of administrative districts of urban. Since these administrative districts units are on a different level with urban and rural areas, the regional safety index provided by MPSS is not be able to direct apply to the rural areas. The purpose of this study is to determine the regional safety index targeting rural areas. To estimate the safety index, we was used for 3 indicators of the MPSS, a fire, a crime, and an infectious disease which are evaluable the regional safety index using an accessibility analysis. For determining the regional safety index using accessibility from community centers to public facilities, the safety index of fire, crime, and infectious disease used access time to fire station, police office, and medical facility, respectively. An integrated Cheongju, targeting areas in this study, is mixed region with urban and rural areas. The results of regional safety index about urban and rural areas, the safety index in rural area is relatively higher than in the urban. Neverthless the investment would be needed to improve the safety in the rural areas.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.353-359
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• 2018

Basic reproductive biology of the daggertooth pike conger, Muraenesox cinereus were investigated based on the samples from August 2015 to December 2017 in Korean waters. A total of 2,328 samples was collected (1,593 females and 735 males) during the study period. The mean anal lengths (AL) were $33.5{\pm}9.2cm$ in females and $26.2{\pm}7.3cm$ in males respectively. The females were larger than males in AL (p < 0.05). Sex ratio was 2.2:1 in female to male (p < 0.05). The gonadosomatic index (GSI) varied monthly. GSI of female reached the maximum in July 2016 and June 2017 and the minimum in October 2016 and September 2017 respectively. The spawning period was from June to October. The size at sexual maturity ($L_{50}$) of females was estimated at 24.9 cm in AL (63.5 cm in TL).

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.12-18
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• 2017

Lots of fishery stocks are overexploited and the overcapacity exists in Korean fishing fleets. One of the reasons is technological development, which increases the efficiency of the vessels continuously. The analysis was conducted to identify the change of fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the offshore large powered purse seine fishery from 1960s to 2010s. Gross tonnage and horse power per fishing vessel was increased annually. Fishing gear material was changed to the knotless webbing to settle faster. Fishing equipments was modernized and supply rate was also increased. Therefore the relative fishing power index in the offshore large powered purse seine fishery increased from 0.4 in 1970 to 1.0 in 1980, to 1.5 in 2000 and to 1.6 in 2010, but the rate of increase slowed down gradually. The results are expected to contribute to reasonable fishery stock management.

• Analytical Science and Technology
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• v.31 no.5
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• pp.195-200
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• 2018

Researchers have used the visual criteria to compare the effectiveness of fingerprint enhancement techniques. However, since the visual criteria is subjective, bias can occur. Therefore, many researchers have tried to make the criteria objective using the contrast index (CI). However, there is a constraint that the CI was only validated on inked fingerprints or color-change fingerprints. In this study, we compared enhancement of fluorescence fingerprints on colored papers using the CI. The CI values differ according to the color of the background, reagent, and light source, even though the same standard fingerprints were used. Through the comparison of values, we could compare the enhancement of fluorescence fingerprints according to these factors. When visual evaluation criteria were used, the same peak score was obtained regardless of the reagent and light source. However, we could get a more detailed score comparison in this study using the CI. Therefore, it is confirmed that for comparison of enhancement of fluorescence fingerprints, the CI can be used as a basis for determining which light source and reagent are appropriate according to the background.

• Safety and Health at Work
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• v.8 no.2
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• pp.220-225
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• 2017

Background: Benzene is a known occupational and environmental pollutant. Its urinary metabolite trans, trans-muconic acid (tt-MA) has been introduced by some environmental and occupational health regulatory associations as a biological index for the assessment of benzene exposure; however, recently, doubts have been raised about the specificity of tt-MA for low-level benzene exposures. In the present study, we investigated the association between urinary levels of tt-MA and inhalational exposure to benzene in different exposure groups. Methods: Benzene exposure was assessed by personal air sampling. Collected benzene on charcoal tube was extracted by carbon disulfide and determined by a gas chromatograph (gas chromatography with a flame ionization detector). Urinary tt-MA was extracted by a strong anion-exchange column and determined with high-performance liquid chromatography-UV. Results: Urinary levels of tt-MA in intensive benzene exposure groups (chemical workers and police officers) were significantly higher than other groups (urban and rural residents), but its levels in the last two groups with significant different exposure levels (mean = 0.081 ppm and 0.019 ppm, respectively) showed no significant difference (mean = $388{\mu}g/g$ creatinine and $282{\mu}g/g$, respectively; p < 0.05). Before work shift, urine samples of workers and police officers showed a high amount of tt-MA and its levels in rural residents' samples were not zero. Conclusion: Our results suggest that tt-MA may not be a reliable biomarker for monitoring low-level (below 0.5 ppm) benzene exposures.

• Korean Security Journal
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• no.17
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• pp.301-316
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• 2008

The occurrence of complicating, multilateral social condition demands the strategy for facing many social state and consolidating public security against criminal loss. The lacking ability of local police for preventing crime can't satisfy the demand of security and can't get rid of fear of crime. At last, it brings a distrust of public confidence and became a factor of serious social crisis. We have problems - not only making an alternative plan for preventing crime, but also introducing CPTED(Crime Prevention Through Environmental Design) by environmental design, to expect crime prevention and to select systemic crime prevention system and the most suitable model. And we have a goal - to recognize the importance of guard activity for local crime, analyse public safety activity in community & focusing guard activity as a strategy for them, apply CPTED in police and private security company as a local crime prevention & setting effective model, and, make it as an index for preventing & dealing with intellectual, brutal crime. The rapid growth in the guarding-activity field lighten the burden of police for crime-prevention. But the misjudgement of some people blocks it to be settled institutionally. It needs to reconsider what is the effective crime-prevention method, at this point of time when the all parts of a nation changing into unlimited competitive, private self-control system.