• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.1
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• pp.45-56
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• 2021

In order to understand the tide and current around the sea route of Jinhae and Masan passages, tide measurement and 2D numerical model experiments of tidal current and residual flow were carried out. Tide is composed of 84% of semi-diurnal tide, 11% of diurnal tide and 4% of shallow water tide, respectively. Phase lags of the major components for the tide around the study area have little differences. The flows are reversing on the whole, but have rotational form around Jamdo Island, south of Masan passage in spring tide and Ungdo Island, north of Masan passage in middle and neap tide. Current flows the speed of 50 cm/s in the sea areas near small islands, 5 cm/s in Jinhae harbor, Hangam bay and near Jinhae industrial complex and 20-30 cm/s in Jinhae passage, Budo channel and Masan passage. Tide-induced topographical eddies are formed near small islands, but few eddies exist and the flow rate of less than 5 cm/s tidal residual current formed in Jinhae and Masan passages. The flows in Jinhae and Masan passage give a good condition for a passage into Jinhae and Masan harbor.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.230-231
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• 2023

This study proposes a deep reinforcement learning-based algorithm to automatically generate a ship's passage plan. First, Busan Port and Gwangyang Port were selected as target areas, and a container ship with a draft of 16m was designated as the target vessel. The experimental results showed that the ship's passage plan generated using deep reinforcement learning was more efficient than the Q-learning-based algorithm used in previous research. This algorithm presents a method to generate a ship's passage plan automatically and can contribute to improving maritime safety and efficiency.

• Journal of Korea Planning Association
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• v.53 no.7
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• pp.5-22
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• 2018

While the competitiveness of small and medium sized cities has become important for balanced development at the national scale, they have experienced continuous decline in population and employment, particularly those in non-capital regions. In addition, some of small and medium sized cities have been classified into shrinking cities that have declined due to their long-term structural reasons. To address these issues, a regional approach, by which a hub city and its surrounding small and medium sized cities can collaborate has been suggested. Given this background, the purpose of this study is to identify and delineate hub cities and their impact areas by using travel data as a functional network index. This study uses a centrality index to identify the hub cities of small and medium sized cities and Markov-chain model and cluster analysis to delineate regional boundaries. The mean first passage time (MFPT) generated from the Markov-chain model can be interpreted as functional distance of each region. The study suggests a methodological approach delineating the boundaries of regions incorporating functional relationships of hub cities and their impact areas, and provides 59 hub cities and their impact areas. The results also provide policy implications for regional spatial planning that addresses appropriate planning boundaries of regions for enhancing the economic competitiveness of small and medium sized cities and ensuring services for shrinking cities.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.439-446
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• 2017

The Maritime Safety Act established restrictions for the passage of oil tankers, prohibiting vessesl carrying more than 1,500 kiloliters of oil or 1,500 tons of a hazardous liquid substance. Prohibited vessels that do not satisfy the restrictions are allowed to enter and depart from a nearby port from the outer sea area to minimize the time and distance the oil tanker must navigate in the prohibited area. Therefore, such regulation should not be construed as referring to inshore traffic. In this study, the traffic volume of coastal tankers that do not use the approaching channels for specific sea areas near Yeosu and Gwangyang Port was analyzed, and the cargo loads of these ships were investigated. The results of this study should be used to allow tankers to minimize the time and distance of navigation in prohibited areas. According to the survey, 16 vessels, 51.6 % of the 31 vessels using inshore traffic included in the study, were loaded with more than 1,500 tons of cargo. This is not appropriate according to the legislation for oil tanker passage. Therefore, in this study, sea routes have been proposed that connect with the approaching channels of specific sea areas, from the outer sea areas of restricted passages. Regulations have also been proposed for the entry and departure of oil tankers around Yeosu and Gwangyang Port.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.417-429
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• 2003

Abnormal oceanic conditions associated with the passage of typhoons are examined using hydrographic and satellite data 1990-2002. During the passage period of typhoons in the Korean waters, an abrupt decrease of sea surface temperature (SST) in range of 5 to $8^{\circ}C$ was observed. The areas of SST decrease were an order of 100-200 km, and the low SST lasted about 15-25 days after passage of typhoon. After passage of typhoon, the water temperatures in the surface mixed layer of 30 m show negative anomalies for quite a long period. In addition, stratification parameters were substantially decreased and chlorophyll a density was rapidly increased.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.640-641
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• 2003

Abnormal oceanic conditions associated with the passage of typhoons are examined using hydrographic and satellite data 1990-2002. During the passage period of typhoons in the Korean waters, an abrupt decrease of sea surface temperature(SST) in range of 5 to 8 $^{\circ}$ was observed. The areas of SST decrease were an order of 100-200km, and the low SST lasted about 15-25 days after passage of typhoon. After passage of typhoon, the water temperatures in the surface mixed layer of 30m show negative anomalies for quite a long period. In addition, stratification parameters were substantially decreased and chlorophyll a density was rapidly increased.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 1992.11a
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• pp.53-61
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• 1992

This study aims to find out about the traditional life and consciousness of the Yi dynasty used its residence as the place where rites of passage were heid. This study is tuying to classify the rites of passage according to the procedures by which those rituals are being held and to analyze them based upon the space where rituals take place. The results of research and analysis are as follows : 1. The most frequently used area in the house as a variety of ceremonies were held includes SARANGBANG and DAECHUNG belonging to SARANGCHE and ANBANG and DAECHUNG that belong to ANCHE. So naturally these areas are located in the main space of the house. 2. ANMADANG as well as SARANGMADANG was used as the main walkway in the house and as the main place for the ceremonies such as marriage and funenal. MADANG space in the house played a semi-indoor-space fole andperformed the functions which limited indoor space couldu's carry out when ceremonies took place. 3. It seems that SADANG had net been utilized in the daily routine but located within the residence due to the ritualism.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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• pp.405-413
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• 1994

This paper presents the experimental results of aerodynamic drags of model cars. The effects of cooling air on total drag were introduced by using momentum theorem. Vehicle-liked Ahmed body and 1/5 model car were used to evaluate the increments of drags due to the internal flow. The results were compared with momentum theorem and other's experiments and showed good agreements. In the case of Ahmed body, drags were increased by 22% due to the internal flow and decreased linealy by reducing internal air flow rates and inlet areas. The experiments on 1/5 model car with ill-defined air flow passage showed 10% increment of drag. The results of present study showed that cooling drag could be predicted by momentum theorem within small errors.

• Journal of Korea Water Resources Association
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• v.41 no.1
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• pp.75-85
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• 2008

The pale chub (Zacco platypus) is a dominant species that migrates locally and inhabits in rivers in Korea. The fish movement at confluences or hydraulic connections is very important especially for the life of small fish as pale chub. If main stream and off-channel habitats are connected with culverts, they would restrict the fish movement due to the high flow velocities and low depths. In foreign conturies, design flow conditions of fish friendly culvert, including flood flow capacity and fish-passage flow capacity, were assigned. Installation of culvert fishways is one way to improve the fish-passing capacity of culverts. On the contrary, in Korea, the design flow of culvert contains only the flood flow capacity. The effect of the fish passage with offset baffles was tested with the fixed velocity method in an experimental flume. As a result, An occasion velocity 1.2m/s, proportional success of pale chubs pass is maximum 20% improve than without baffle flume for energy dissipate. Offset baffle fishway(baffle height 5cm) provides that resting areas and/or a continuous channel of low velocity water in culverts. Especially, short baffle areas are domain where the pale chubs pass. And, FLOW-3D, a three dimentional numerical model, was used in order to evaluate detailed hydraulic characteristics and application possibility in a culvert fishway design.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.76-81
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• 2014

Purpose: Diversity and the lachrymal duct deformities and the passage inside the nasal cavity except for anterior image such as epiphora happens during the test were able to express more precisely during the dacryoscintigraphy. Also, we thought about the necessity of a method to classify the passage into the naso-lachrymal duct from epiphora. Therefore, we are to find the validity of the method to obtain both oblique views except for anterior views. Materials and Methods: The targets of this research are 78 patients with epiphora due to the blockage at the lachrymal duct from January 2013 to August 2013. Average age was $56.96{\pm}13.36$. By using a micropipette, we dropped 1-2 drops of $^{99m}TcO4^-$ of 3.7 MBq (0.1 mCi) with $10{\mu}L$ of each drop into the inferior conjunctival fold, then we performed dynamic check for 20 minutes with 20 frames of each minute. In case of we checked the passage from both eyes to nasal cavity immediately after the dynamic check, we obtained oblique view immediately. If we didn't see the passage in either side of the orbit, we obtained oblique views of the orbit after checking the frontal film in 40 minutes. The instrument we used was Pin-hole Collimator with Gamma Camera(Siemens Orbiter, Hoffman Estates, IL, USA). Results: Among the 78 patients with dacryoscintigraphy, 35 patients were confirmed with passage into the nasal cavity from the anterior view. Among those 35 patients, 15 patients were confirmed with passage into the nasal cavity on both eyes, and it was able to observe better passage patterns through oblique view with a result of 8 on both eyes, 2 on left eye, and 1 on right eye. 20 patients had passage in left eye or right eye, among those patients 10 patients showed clear passage compared to the anterior view. 13 patients had possible passage, and 30 patients had no proof of motion of the tracer. To sum up, 21 patients (60%) among 35 patients showed clear pattern of passage with additional oblique views compared to anterior view. People responded obtaining oblique views though 5 points scale about the utility of passage identification helps make diagnoses the passage, passage delayed, and blockage of naso-lachrymal duct by showing the well-seen portions from anterior view. Also, when classifying passage to naso-lachrymal duct and flow to the skin, oblique views has higher chance of classification in case of epiphora (anterior:$4.14{\pm}0.3$, oblique:$4.55{\pm}0.4$). Conclusion: It is considered that if you obtain oblique views of the bilateral orbits in addition to anterior view during the dacryoscintigraphy, the ability of diagnose for reading will become higher because you will be able to see the areas that you could not observe from the anterior view so that you can see if it emitted after the naso-lachrymal duct and the flow of epiphora on the skin.