• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.321-330
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• 2022

Busan New Port manages the largest volume of traffic among Korean ports, and accounts for 68.5% of the total volume of the Busan port. Due to this increase in volume, ultra large container ships call at Busan New Port. When the additional south container terminal as well as ongoing construction project of the west container terminal are completed, various encounters may occur at the Busan New Port entrance, which may cause collision risk.s Thus, the purpose of this study was to provide a plan to improve the safety of vessel traffic, in the in/out bound fairway of Busan New Port. For this purpose, the status of arrivals and departures of vessels in Busan New Port, was examined through maritime traffic flow analysis. Additionally, risk factors and safety measures were identified, by AHP analysis with ship operators of the study area. Also, based on the derived safety measures, scenarios were set using the Environmental Stress model (ES model), and the traffic risk level of each safety measure was identified through simulation. As a result, it is expected that setting the no entry area for one-way traffic would have a significant effect on mitigating risks at the Busan New Port entrance. This study can serve as a basis for preparing safety measures, to improve the navigation of vessels using Busan New Port. If safety measures are prepared in the future, it is necessary to verify the safety by using the traffic volume and flow changes according to the newly-opened berths.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.210-217
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• 2014

In this paper, the volume of ODA of Korea to developing countries has been analysed quantitatively based on statistical information, compared with Korea's ODA in the scope of the maritime industry. Thereafter, norms and policies of ODA in OECD DAC and trends of ODA in international societies have been examined through literature and qualitative researches so that possible ways to forward in Korea's ODA have been proposed. Hence, in this paper it h as been recognized that the volume of ODA related with the Korean maritime industry has been standing still as the before despite tremendous increase of total volume of Korea's ODA. for last 10 years. Consequently, the paper would like to propose possible measures that might been taken by the Korean government to raise the volume of ODA related with the maritime industry.

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.531-539
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• 2003

Changes in the rat testis interstitium from birth to adulthood were studied using Sprague Dawley rats of 1, 7, 14, 21, 28, 40, 60, and 90 days of age to investigate Leydig cell differentiation. In addition, serum testosterone concentrations and luteinizing hormone stimulated (LH; 100 ng/ml) testosterone secretory capacity per testis in vitro were determined via radioimmunoassay. Fetal Leydig cells were present in rat testes from birth to 21 days, and they were only steroidogenic cells in the testis at days 1 and 7. The average volume of a fetal Leydig cell and the absolute volume of fetal Leydig cell per testis were similar at all ages of experimental groups except at day 21 when lower values were observed for both parameters. The number of fetal Leydig cells per testis remained constant from birth through 21 days. Adult Leydig cells were recognized at day 14 and their absolute volume and number per testis increased linearly from 14 to 90 days. The average volume of an adult Leydig cell increased significantly with age and reached maximum size by 60 days of age where the volume was nearly three times bigger than that of at day 14. Total testosterone production per testis in vitro and serum testosterone concentrations were not significantly different at day 1 compared with 7, 14, and 21 days of age. Significant increases were observed at days 40 and 60. Values at days 60 and 90 were not significantly different.

• Korean Journal of Veterinary Service
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• v.39 no.3
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• pp.141-149
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• 2016

Changes in the Leydig cell from pre-puberty to adulthood were studied in Korean native cattle. Eight groups of male cattle aged 14, 17, 20, 25, 30, 35, 40 and 104 weeks (n=7 cattle per group) after birth were used. The purpose of this study was to obtain quantitative information on the Leydig cell of the Korean native cattle during postnatal development. Testes of cattle were fixed by perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using $1{\mu}m$ section stained with methylene blue-azure II, qualitative and quantitative (stereological) morphological studies were performed. The average diameter of seminiferous tubules gradually increased with age from 14 ($75.56{\mu}m$) to 104 weeks ($298.9{\mu}m$). The volume density of the seminiferous tubules increased with age from 54.2% at week 14 to 76.9% at week 104. The volume density of the interstitium represents 45.52% at week 14. This proportion progressively diminishes during development to reach a value of 23.14% at week 104. The volume density of Leydig cells decreased almost linearly from 14 (20.71%) to 104 weeks (5.28%). The absolute volume of Leydig cells per testis increased significantly from 14 to 104 weeks. The number of Leydig per testis have almost linearly increased from 14 to 104 weeks. The average volume of a Leydig cell reached maximum size by 104 weeks ($2553{\mu}m^3$). These data suggested development of Leydig cell can be classified as the fetal and immature adult Leydig cells (14~35 weeks), and the adult Leydig cells (40~104 weeks).

• Journal of the Korean Institute of Gas
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• v.3 no.3 s.8
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• pp.23-28
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• 1999

Variation of explosion characteristics by the blocks in closed vessel was investigated to analyse the effect of the block volume(volume blockage) and the surface area of the blocks(ratio of block surface area to vessel volume). Volume and surface area of blocks in explosion vessel were changed by the combination of blocks. The volume of explosion vessels was 270 liter, and the LPG-air or NG-air mixtures were ignited by the electric spark. Explosion pressure was measured with the strain type pressure transducer. From the experimental results, explosion pressure was decreased by the increase of the volume blockage and the block surface area. And the decrease of explosion pressure was more affected by the volume blockage than the surface area.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.153-159
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• 2016

Gwangyang traffic safety designated area is composed of 3 fairways (Deep water fairway, inbound fairway, and outbound fairway). However, inbound vessels can't use this passage because of Samyeo rock and artificial fishing banks in inbound route. The problem with the rocks and artificial fishing banks has been raised by ship navigators and authorities of the port. This research is about the safety evaluation and management plan of the passage, and we conducted maritime traffic simulation using a model based on a ship operator risks. As a result, assuming that future marine traffic volume is the same as the present, and if the ship operators use 3 fairways and not two, it showed risk reduction of 46.4 % (vessels over 50,000 DWT using DW route) and 57.1 % (vessels over 10,000 DWT using DW route). Also, in a traffic volume condition which is the same as the present, to induce vessels over 50,000 DWT to use DW route is effective in mitigating of risks. Meanwhile, in a condition which increased the traffic volume by 150 %, it is more effective to induce vessels to use DW route. This research is the result of analysis using the model based on ship operator risks, and not cost-effectiveness analysis on the removal of Samyeo rock and artifical fishing banks. This research is expected to be used on setting up the sea route and management plan (particularly, restriction on passing DW route).

• Journal of the Korean Society of Safety
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• v.13 no.4
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• pp.256-263
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• 1998

In this paper, we propose a volume holographic fingerprint recognition system based on optical correlator for personal identification. Optical correlator has high speed and parallel processing characteristics of optics. Matched filters are recorded into a volume hologram that can store data with high density, transfer them with high speed, and select a randomly chosen data element. The multiple reference images of database are prerecorded in a photorefractive crystal in the form of Fourier transform images, simply by passing the image displayed in a spatial light modulator through a Fourier transform lens. The angular multiplexing method for multiple holograms of database can be achieved by rotating the crystal by use of a step motor. Experimental results show that the proposed system can be used for the security verification system.

• Journal of the Korea Safety Management & Science
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• v.25 no.2
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• pp.91-97
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• 2023

Ensuring the safe arrival of delivery cargo at its intended destination is of utmost importance. Truck drivers play a crucial role in guaranteeing the secure delivery of cargo without any mishaps. However, there are various factors that may lead to delayed arrival of trucks at their destination, such as late departures or prolonged loading operations. The timely departure of cargo transportation is contingent upon several variables, including the driver's experience, cargo volume, and loading time. If the transportation commencement is delayed, it may increase the risk of accidents due to an elevated operating speed. Consequently, we conducted a study to investigate the correlation between cargo loading time, cargo volume, driving experience, and the likelihood of accidents. Our findings indicate that both cargo volume and driver experience can impact the likelihood of vehicle accidents. Furthermore, all factors can have an interactive effect on the occurrence of accidents. However, extending the loading time may mitigate the impact on the likelihood of accidents.

• Journal of Korean Society on Water Environment
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• v.29 no.1
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• pp.45-54
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• 2013

This study analyzes the reduction effects of runoff and flood damage through different arrangements of stormwater storage facilities. Three scenarios based on the spatial allocation of storage capacity are used: concentrated, decentralized and combinative. The characteristics of runoff and flood damage by scenario are compared. The XP-SWMM model is used for runoff simulation by the probable rainfall of return period. The result shows that the concentrated arrangement of storage facilities is most effective to reduce the amount of peak flow and to delay the time of peak flow. Yet, while the concentrated arrangement is most effective to reduce the inundation damage, it is not effective to reduce runoff volume. The decentralized arrangement is most effective to reduce runoff volume. The combinative arrangement is effective not only the runoff reduction but also the reduction of flood damage. The result indicates that the flood mitigation strategies against heavy rainfall need to consider decentralized on-site arrangement for the reduction of runoff volume along with concentrated off-site arrangement of storage facilities.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.103-110
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• 2009

Since the mechanical properties of cement-based materials are time-dependent due to the prolonged cement hydration process, those of fiber reinforced concrete(FRC) may also be time-dependent. Toughness is one of important properties of FRC. Therefore, it should be investigated toughness development of FRCs with curing ages to fully understand the time-dependent characteristics of FRCs. To this end, the effect of curing ages on flexural toughness development of steel fiber reinforced concrete is studied. Three point bending test with notched beam specimen was adapted for this study. Hooked-end steel fiber(DRAMIX 40/30) was used as a fiber ingredient to investigate w/c ratio and fiber volume fraction effect on toughness development during curing. Three different water-cement ratios(0.44, 0.5 and 0.6) and fiber volume fractions(0%, 0.5% and 1%) were used as influence factors. Each mixture specimens were tested at five different ages, 0.5, 1, 3, 7 and 28 days. The study shows that flexure toughness development with age is quite different than other concrete material properties such as compressive strength. The study also shows that the toughness development trend correlates more closely to water/cement ratio than to fiber volume fraction.