• Journal of Navigation and Port Research
• /
• v.42 no.6
• /
• pp.469-477
• /
• 2018

Most of the current administrative names and locations for the names of places in the Nanjung diary have since been confirmed. However, a disagreement ensued among translators or researchers over Anpyeon-do (Baleum-do) islet recorded in Admiral Yi Sun-Shin's diary. Anpyeon-do was first recorded in the diary on October 11, 1597. It is credited to be the location where Yi Sun-shin and Chosun Naval Fleet stayed when sailing along the Southwestern coast of the Korean Peninsula after the battle of Myeongnyang. However, Anpyeon-do's exact geographical location has never been accurately confirmed. To accurately locate the islet, this study compared the direction and position of geographical locations observed in the Anpeon-do site match to actual geographical positions and directions. In addition, the direction and position of the geographical locations observed in the newly explored islands and mountains were evaluated with regard to how they correspond to the actual Anpeon-do. As a result, we concluded that the real location of Anpyeon-do recorded in the Nanjung diary is the Maebong mountain in Anjwa-do.

• Economic and Environmental Geology
• /
• v.47 no.5
• /
• pp.533-540
• /
• 2014

The Wangdol-cho area, in the Hupo Bank, plays a very important role in main fishing grounds, leisure tourism and marine environmental researches of the East Sea. We analyzed the detailed bathymetry and classified the seabed characteristics of the Wangdol-cho area, based on seafloor backscattering images and sediment grain size. The Hupo Bank is developed in parallel with the eastern coastal line of Korean peninsula, and the shallowest area (Wangdol-cho) of the Hupo Bank is located along the eastern part of Hupo Port. The Wangdol-cho comprises three summits; north summit, middle summit, and south summit. The middle summit area among the three summits has the most shallow water depth with minimum about 6 m. The north summit shows about 8 m minimum depth and the south summit about 9 m. The bathymetry data around three summits represent undulating seabeds with many scattered underwater reefs and shallow water depth. The area between the underwater reefs, the flat seafloor in the northeastern part of the survey site, and the western steep slope area have relatively coarse sediments such as sandy gravel and gravelly sand. The bathymetry in the western side of the Wangdol-cho shows steep slope seabed, extending to the Hupo Basin. Fine sediments including mud and silty sand occur in the Hupo Basin area of the survey site. The submarine detailed topography and the analysis of the seafloor characteristics of the survey area are expected to contribute to management for marine environmental researches and sustainable use of ecosystems in the Wangdol-cho.

• Economic and Environmental Geology
• /
• v.41 no.6
• /
• pp.747-761
• /
• 2008

In order to experiment the acoustic remote classification of seabed sediment, we achieved ground-truth data(i.e. video and grab samples, etc.) and developed post-processing for automatic classification procedure on the basis of 300 kHz MultiBeam Echo Sounder(MBES) backscattering data, which was acquired using KONGBERG Simrad EM3000 at Sock-Cho Port, East Sea of South Korea. Sonar signal and its classification performance were identified with geo-referenced video imagery with the aid of GIS (Geographic Information System). The depth range of research site was from 5 m to 22.7 m, and the backscattering amplitude showed from -36dB to -15dB. The mean grain sizes of sediment from equi-distanced sampling site(50 m interval) varied from 2.86$(\phi)$ to 0.88(\phi). To acquire the main feature for the seabed classification from backscattering amplitude of MBES, we evaluated the correlation factors between the backscattering amplitude and properties of sediment samples. The performance of seabed remote classification proposed was evaluated with comparing the correlation of human expert segmentation to automatic algorithm results. The cross-model perception error ratio on automatic classification algorithm shows 8.95% at rocky bottoms, and 2.06% at the area representing low mean grain size.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.11 no.3
• /
• pp.219-228
• /
• 2011

In this paper, the design procedure of substructure of the steel-type breakwater was described and the actual foundation design was performed for the test bed. The site investigation was executed at the Osan-port area, in Uljin, Gyeongbuk, where the steeltype detached breakwater is constructed. The foundation mainly depends on the lateral load and uplift force due to the wave force. Since the superstructure is stuck out about 9.0m from the ocean bed, the foundation must resist on the lateral force and bending moment. After considering various factors, the foundation type of this structure was determined by the steel pipe pile(${\varphi}711{\times}t12mm$). On the stability of pile foundation, the safety factors of the pile on the compressive, lateral and uplift forces were grater than the minimum factor of safety. The displacements of pile under the working load were evaluated as the values below the permissible ones. Based on the subgrade reaction method, we evaluated the relationship of subgrade reaction and displacement for the lateral and the vertical directions in the layers. The structural analyses along with the foundation were perfomed and the effect of pile foundations were compared quantitatively.

• Korean Journal of Heritage: History & Science
• /
• v.49 no.2
• /
• pp.158-171
• /
• 2016

The observation and analysis results of 9 glass bead samples collected from Oc Eo site in Vietnam, an outport of the ancient port city Funan in East Asia, are as follows. The type of glass beads is round, the colors are reddish brown, greenish blue, green, black and purplish blue, and the chemical composition is soda glass group. This means that they are similar in type, color and chemical compositions to glass beads from the ancient Korean peninsula. There are limitations in data because the glass beads are not from excavation investigation but from earth surface investigation. But it is significant that similar making technique and chemical composition are being observed in both the glass beads from Oc Eo and those of Korea. According to "Nihon Shoki" Kinmeiki, Baekje king sent Funan's goods and 2 slaves to Japan in 543. It is clear that there were direct or indirect exchanges between Baekje and Funan. The possibility has grown that glass beads could be included among goods.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.6C
• /
• pp.339-347
• /
• 2008

The penetration of the probe produces the excess pore pressure due to the disturbance. The objective of this study is to evaluate the disturbance zone by using the dissipation of the excess pore water pressure, which was generated due to the penetration of the penetrometer with different size. The CPT, DMT and FVP (Field Velocity Probe) are adopted for in-situ tests. The tests are carried out in the construction site of north container pier of Busan new port, Korea where is accelerating the consolidation settlement using plastic board drains (PBD) and surcharges by crushed gravels. The coefficient of consolidation $(C_h)$ and soil properties are deduced by the laboratory test. The in-site tests are performed after the predrilling the surcharge zone at the point of 90% degree of consolidation. To minimize the penetration effect, the horizontal distance between penetration tests is 3m, the change of the pore pressure is monitored at the fixed depth of 24m. The coefficient of consolidation $(C_h)$ and the $t_{50}s$ are calculated based on the laboratory test and the in-situ data, respectively. The equvalent radi based on the $t_{50}$ shows that the FVP and the DMT produce the smallest and the greatest equivalent radi, respectively.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.14 no.3
• /
• pp.209-221
• /
• 2002

In the present paper, a method which enhances the circulation of harbor waters by using wave energy was investigated. The overflow levee was selected as a coastal structure helping the harbor circulation, and was applied to Jeju-outer-port site so as to estimate its effectiveness quantitatively in probabilistic point of view. It was assumed that sea water influx rate through the overflow levee into the harbor depended upon wave height and tidal level and a functional relationship among them was calculated using the results of hydraulic experiment. The probability distribution of water influx could be obtained from hindcasted wave data and measured tidal elevations at Jeju harbor. The Gamma distribution was appeared to best fit the estimated influx distribution, and the optimal location of the levee was discussed. Finally, water quality purification effect was investigated by computing the contaminant material dispersion according to whether the levee was or not.

• Journal of Gastric Cancer
• /
• v.14 no.2
• /
• pp.105-110
• /
• 2014

Purpose: The advantages of totally laparoscopic surgery in early gastric cancer (EGC) are unproven, and some concerns remain regarding the oncologic safety and technical difficulty. This study aimed to evaluate the technical feasibility and clinical benefits of totally laparoscopic distal gastrectomy (TLDG) for the treatment of gastric cancer compared with laparoscopy-assisted distal gastrectomy (LADG). Materials and Methods: A retrospective review of 211 patients who underwent either TLDG (n=134; 63.5%) or LADG (n=77; 36.5%) for EGC between April 2005 and October 2013 was performed. Clinicopathologic features and surgical outcomes were analyzed and compared between the groups. Results: The operative time in the TLDG group was significantly shorter than that in the LADG group (193 [range, 160~230] vs. 215 minutes [range, 170~255]) (P=0.021). The amount of blood loss during TLDG was estimated at 200 ml (range, 100~350 ml), which was significantly less than that during LADG, which was estimated at 400 ml (range, 400~700 ml) (P<0.001). The hospital stay in the TLDG group was shorter than that in the LADG group (7 vs. 8 days, P<0.001). One patient from each group underwent laparotomic conversion. Two patients in the TLDG group required reoperation: one for hemostasis after intraabdominal bleeding and 1 for repair of wound dehiscence at the umbilical port site. Conclusions: TLDG for distal EGC is a technically feasible and safe procedure when performed by a surgeon with sufficient experience in laparoscopic gastrectomy and might provide the benefits of reduced operating time and intraoperative blood lossand shorter convalescence compared with LADG.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.30 no.1
• /
• pp.61-74
• /
• 2002

The purpose of this study is to propose vegetation management devices through analyzing the actual vegetation, flora, plant community structure and soil chemical concentrations in Weolmi urban nature park, Incheon. The actual vegetation of Weolmi Park in various areas is composed of urbanization area(2 types, 25.9%), landscape planting area(4 types, 16.1%), grass and marsh area(5 types, 7.6%) and mountain forest areal(14 types, 50.4%). The flora is composed of 295 taxa with 80 families, 253 species, 35 varieties and 7 formas, and among them there are 16 naturalized plant families, 39 species, 3 varieties. In reflection of size, the number of the species seems high but most of the them are under influence of human disturbance. Nine survey plots of plant community structure are classified into two groups. One is the semi-natural plant community(Prunus sargentii-Acer palmatum, Quercus accutissma-Prunus sargentii, Quercus serrata-Quercus accutissma-Prunus sargentii, Prunus sargentii, and Zelkova serrata-Prunus sargentii) that migrated finn the planting forest to the natural forest and the other is planting forest(Pinus koraienssis-Pinus thunbergii-Abies holophylla-Chamaectparis obtusa, Prunus sargentii, Pinus thunbergii-Alnus firma, Zelkova serrata). The average pH is 4.65 which means the soil acidity is quite high. The concentration of K, Ca, Mg and base saturation is very low. It seems that the environmental pollutants from Incheon Port and industrial plants near by survey site and long-distance transport of air pollutants from China made the soil condition worse. On the basis of the results above, six vegetation management devices are suggested: 1) removing the hazard plants(Pueraia thunbergiana and Humulus japonica), 2) natural landscape management of the middle and long term, 3) increasing species diversity, 4) Robinia pseudoacacia management, 5) keeping the naturalized plants from being distributed any further inside the mountain forest, 6) improving soil acidification.

• Journal of Ocean Engineering and Technology
• /
• v.21 no.2 s.75
• /
• pp.22-34
• /
• 2007

We present basic data for developing new research topics and closely examine the existing data on the development and organization of the Nakdong River Estuary Delta by analyzing various studies of the area, including ocean engineering, coastal engineering, ocean environmental engineering, geomorphological, and geological studies. We first defined the general concepts related to the estuary and delta and reviewed the historical development of the Nakdong River Estuary Delta over the past 100 years. We then examined the origin and core elements of the estuary deposits that constitute the delta. In addition, we scrutinized the main factors affecting the development of the delta and analyzed existing research on delta development mechanisms by core researchers. The construction of an estuary barrage is one of the main factors effecting estuarine circulation and has altered the physical oceanic environment, area of deposition, atmospheric environment, and vegetation community of the delta. These factors affect the estuary circulation in turn, altering the delta. Along the Nakdong River, an unsteady-state sandy barrier appears at approximately three times the distance of the wavelength of incident offshore waves, and this terrain forms approximately 10-15 years after reclamation in the interdistributary upper stream and transforms the shoreline. It is necessary to develop a technique to predict terrain change that reproduces the erosion and accumulation of estuarine deposits. To determine the parameters and variables necessary to reproduce this system, continuous on-site monitoring is necessary. The existing research did not fully examine the terrain changes in Nakdong River Estuary or the periodic developmental characteristics. To understand the future process of estuary delta development, it is necessary to establish an integrated management system.