• Journal of the Korean GEO-environmental Society
• /
• v.7 no.4
• /
• pp.53-62
• /
• 2006

Recently, the lateral displacement of the passive piles which are installed under the revetment on the soft ground is very important during the land reclamation work along the coastal line. The revetment on the soft clay develops the lateral displacement of ground when the revetment loading exceeds a certain limit. The lateral displacement of ground causes an excessive deformation of underground structure itself and develops lateral earth pressure against the pile foundation. The subject of study is to investigate the lateral displacement of pile foundation during the construction of container terminal at the ${\bigcirc}{\bigcirc}{\bigcirc}{\bigcirc}$ port in Incheon. The displacement of pile and the vertical settlement were measured in the field and finite element method(FEM) analysis for each construction sequence was performed using AFFIMEX(Ver 3.4). From the comparison of the results from field measurement and the finite element analysis, the settlement of the reventment has already occurred at the time of field measurements. Since then, the noticeable lateral displacement of piles and settlement were occurred during the filling of dredged soil inside the revetment dredging and reclaiming work. After completing filling, the lateral displacement and field settlement were reduced remarkably. Generally, the results from the finite element analysis show larger than those from the measurement.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.32 no.3
• /
• pp.170-179
• /
• 2020

Tidal asymmetry would occur owing to shallow water tides at the Western Coast of macro tidal area. Especially, as ebb dominance of Mokpo coastal zone is known as the most prominent in Korea, it had been studied by domestic researchers. The cause of ebb dominance in Mokpo area is considered due to extensive inter-tidal zone in Muan Bay, and this has been studied based on amplification ratio, relative phase and skewness of tide/tidal flow curves in order to analyze qualitative tidal asymmetry. Furthermore, it was possible to figure out tidal characteristics with the difference of tidal amplitude and phase with Mokpo Harbor by observing the tide for 15 days in Muan Bay, which showed 40 minutes shorter ebbing time than at Mokpo Harbor. In addition, tidal flow prediction data in Mokpo North Harbor and Mokpo-Gu were analyzed. Meanwhile, the basis regarding qualitative interpretation of bed sediment and suspended sediment was provided by examining the qualitative changes in tidal asymmetry for spring-neap tidal cycle through the PCA/SWA indices. In addition, by examining long-term changes of ebb dominance in Mokpo Port, tidal characteristics of the past, present and future in this area, which is related to tidal asymmetry, is also provided.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.27 no.1
• /
• pp.63-77
• /
• 2015

Tsunami take away life, wash houses away and bring devastation to social infrastructures such as breakwaters, bridges and ports. The coastal structure targeted object in this study can be damaged mainly by the wave pressure together with foundation ground failure due to scouring and liquefaction. The increase of excess pore water pressure composed of oscillatory and residual components may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, the bore was generated using the water level difference, its propagation and interaction with a vertical revetment analyzed by applying 2D-NIT(Two-Dimensional Numerical Irregular wave Tank) model, and the dynamic wave pressure acting on the seabed and the surface boundary of the vertical revetment estimated by this model. Simulation results were used as input data in a finite element computer program(FLIP) for elasto-plastic seabed response. The time and spatial variations in excess pore water pressure ratio, effective stress path, seabed deformation, structure displacement and liquefaction potential in the seabed were estimated. From the results of the analysis, the stability of the vertical revetment was evaluated.

• Journal of the Korean Institute of Navigation
• /
• v.17 no.4
• /
• pp.1-21
• /
• 1993

The purpose of this paper is to search for reasonable and fair principles applicable to the delimitation of the Exclusive Economic Zone(which is called the EEZ, hereinafter) around the Korean Peninsula th-rought the comprehensive study of maritime boundary, which is one of the most important issues in the law of the Sea. So far, the sea has been exploited for activities such as fishery, transport and military stratedy, and en-vironmental policy and so on. From this time on, however, it becomes important to us as the major trea-sure-house of various resources which will be developed and used for diversified purposes. For these rea-sons, nowadays, more and more countries of the world are competing to secure waters as much as possible within their jurisdiction. And the regime of the EEZ was created as a result of this international trend. At last, it has been institutionalized as the 200-mile EEZ of a legal notion in the Convention on the Law of the Sea, which was adopted at the Third United Nations Conference on the Law of the Sea, in Jamaica on December 10, 1982. In adapting to this EEZ institution, Korea is faced with several complicated problems as it is bounded on three sides by the sea and all of its neighboring countries such as the PRC, the DPRK, Japan, Russia etc are less than 400 miles away between opposite countries. Therefore, when trying to delimit the boun-dary for the EEZ, it appears necessary to analyze applicable principles and rules of international law for delimitation mainly through the Convention on the Law of the Sea, and studies the trends of actual State practices and recent international precedents. It is hoped that such knowledge will enable Korea to secure sufficient resources and other sovereign rights without conflicting with the neighboring countries concer-ned. For the achievement of the above mentioned object. I analyzed the necessities of the establishment of the EEZ in Korea, the difficulties and practices of Korea's neighbors, and the changes and forthcoming trends in Korea's relations with its neighbors concerned on the basis of the general explanation of the EEZ regime. In conclusion, it is my opinion that for the establishment of the EEZ delimitation which neighbors around the Korean Peninsula should be applied reasonable and equitable principles considering the rele-vant circumstances which characterize the area definitely as well as the UN Convention on the Law of the Sea, 1982.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.11B
• /
• pp.938-945
• /
• 2004

This paper describes the problems of the existing two multi-layer routing policies(policy 1 and policy 2) and suggests new multi-layer routing policy(policy 3) which is established the packet LSP by inquiry on packet LSP lambda routing tables for GMPLS based optical If Network. All policies of multi-layer routing schemes first try to allocate a newly requested electrical path to an existing optical path that directly connects the source and destination nodes. U such a path is not available, all policies employ different procedures. Policy 1 tries to find available existing optical paths with two or more hops that connect the source and destination nodes and policy 2 tries to establish a new one-hop optical path between source and destination nodes. Policy 3 tries to establish a new one-hop optical path by inquiry on information of the packet LSP lambda routing tables between source and destination nodes. The performances of the three multi-routing policies are evaluated by computer simulation. Simulation results show that policy 3 is the excellent of routing time and traffic acceptance capabilities compare to existing two polices if p is large, where p is the number of packet-switching-capable ports p.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.12
• /
• pp.9-16
• /
• 2016

Wireless sensor networks (WSN) are composed of sensor nodes and a base station. The sensor nodes deploy a non-accessible area, receive critical information, and transmit it to the base station. The information received is applied to real-time monitoring, distribution, medical service, etc.. Recently, the WSN was extended to mobile wireless sensor networks (MWSN). The MWSN has been applied to wild animal tracking, marine ecology, etc.. The important issues are mobility and energy consumption in MWSN. Because of the limited energy of the sensor nodes, the energy consumption for data transmission affects the lifetime of the network. Therefore, efficient data transmission from the sensor nodes to the base station is necessary for sensing data. This paper, proposes an energy consumption model using two-tier clustering in mobile sensor networks (TTCM). This method divides the entire network into two layers. The mobility problem was considered, whole energy consumption was decreased and clustering methods of recent researches were analyzed for the proposed energy consumption model. Through analysis and simulation, the proposed TTCM was found to be better than the previous clustering method in mobile sensor networks at point of the network energy efficiency.

• Radiation Oncology Journal
• /
• v.32 no.3
• /
• pp.147-155
• /
• 2014

Purpose: This study was conducted to observe the outcomes of postoperative radiotherapy (PORT) with or without concurrent chemotherapy in resected non-small cell lung cancer (NSCLC) in single institution. Materials and Methods: From 2002 to 2013, 78 patients diagnosed with NSCLC after curative resection were treated with radiotherapy alone (RT, n = 48) or concurrent chemoradiation (CCRT, n = 30). The indications of adjuvant radiation therapy were N2 node positive (n = 31), close or involved resection margin (n = 28), or gross residual disease due to incomplete resection (n = 19). The median radiation dose was 57.6 Gy (range, 29.9 to 66 Gy). Results: Median survival time was 33.7 months (range, 4.4 to 140.3 months). The 5-year overall survival (OS) rate was 49.5% (RT 46% vs. CCRT 55.2%; p = 0.731). The 3-year disease-free survival rate was 45.5% (RT 39.4% vs. CCRT 55.3%; p = 0.130). The 3-year local control rate was 68.1% (RT 64.4% vs. CCRT 77.7%; p = 0.165). The 3-year DMFS rate was 56.1% (RT 52.6% vs. CCRT 61.7%; p = 0.314). In multivariate analysis, age ${\geq}66$ years and pathologic stage III were significant poor prognostic factors for OS. Treatment failure occurred in 40 patients. Four patients had radiologically confirmed grade 3 radiation pneumonitis. Conclusion: In NSCLC, adjuvant RT or CCRT after curative surgery is a safe and feasible modality of treatment. OS gain was seen in patients less than 66 years. Postoperative CCRT showed a propensity of achieving better local control and improved disease-free survival compared to RT alone according to our data.

• Clean Technology
• /
• v.23 no.1
• /
• pp.54-63
• /
• 2017

Volatile organic compounds (VOCs) are widely used in both industrial and domestic activities. VOCs are one of the most unpleasant, frequently complaint-rousing factors of pollution around the world. It is now necessary to research and develop an alternative technology that could overcome the problems of the existing odor-control and VOC-eliminating techniques. In this study, essential oil and photocatalytic process was applied in the removal of benzene and toluene, typical VOCs in petrochemistry plant. therefore, this study conducted experiments on the selection of appropriate essential oil, photodegradation, hydroxyl radical generation capacity. The removal efficiency and reaction rate were performed to selecte the type and concentration of essential oil. As a result, removal efficiency of Hinoki Cypress oil was approximately 70% and reaction rate of Hinoki Cypress was high. The results of photolysis experiment, photocatalytic oxidation process showed that the decomposition efficiency of VOCs increased considerably with increasing UV lamp power. In addition, the conversion of VOCs was increased up to $0.1gL^{-1}$ photocatalysts. The hydroxyl radicals measure was performed to determine the ability to generate hydroxyl radicals. The analytical result showed that high $TiO_2$ concentration and lamp power was produced many hydroxyl radical. Experiments of the removal efficiency and reaction rate were performed using essential oil and photooxidation. As a result, the removal efficiency showed that the removal efficiency was increased high temperature and reaction time. The activation energy was calculated from the reaction rate equation at various temperature condition. Activation energy was approximately $18kJmol^{-1}$.

• Journal of the Korean Geotechnical Society
• /
• v.18 no.2
• /
• pp.147-160
• /
• 2002

According to the Korean Design Code for port and harbor facilities, bearing capacity of rubble mound under eccentric and inclined load is calculated by the simplified Bishop method, and strength parameters are recommended to be c=0.2kg/$cm^2$ and \phi=35^P\circ}$ fur standard rubble if the compressive strength of parent rock is greater than 300kg/$cm^2$, according to research results by Junichi Mizukami(1991). But this facts have never been verified in Korea because there was no large-scale triaxial test apparatus until 2000 in Korea. For the first time in Korea, the large-scale triaxial test(sample diameter 30cm ; height 60cm) on the rubble originated from porous basalt rock in North-Cheju was accomplished. Then strength parameters for basalt rubble produced in North-Cheju are recommended to be c:0.3kg/$cm^2\; and \phi=36^{\circ}$ if the compressive strength of parent rock is greater than 400kg/$cm^2$. And the shear behavior characteristics of rubble, represented as particle breakage and dilatancy, are investigated.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.6
• /
• pp.637-645
• /
• 2018

This study analyzes the problem of lack of anchorage caused by some anchorage closed and suggests ways to improve Masan anchorage. For this, we established the evaluation criteria, and analysed the anchorage operating rate during 5 years after estimating the capacity of barge, and suggested improvement plan after appropriateness assessment of anchorage capacity, finally verified the anchorage improvement plan. As a result of study, it is analyzed that the Masan A-2, A-4, A-6 anchorage needs to expand the anchorage due to excess the anchorage assessment criteria of 60 %. So, in order to improve the Masan anchorage, we suggested the improvement plan that extended 1.8 times by the group designated anchorage, according to integrating the A-2, A-4, A-6 anchorage and anchorage dwell time and ship type. And, the result of verification improvement plan, it is analyzed that meet the assessment criteria since decreasing the anchorage operating rate by 1/2 compared to the existing one, does not act as a risk factor in terms of maritime traffic.