• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.6
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• pp.533-546
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• 2007

This paper studied the design VE (Value Engineering) process among the various methods to satisfy the requirement of user and cost saving in the overall redesign process for the Turn-key base construction project. This study has been estabilished the rational and practical analysis process with the stepwise by using the design VE process. The efficiency and safety were verified with the adoptian of computer simulation to cope with the problem of initial analysis and verification for design VE process in the large construction project. In the previous design VE process, there is a limitation for the analysis of design VE in the planing stage and the execution time period of the large construction project. The previous application of VE technique was only for the construction of harbor facilities, so there was no contribution of cost saving in the function and construction. However, this paper proposed the selection methodology of VE items and hence the redesign VE process can be efficiently improved. It can be also improved the process of functional analysis rationally and practically. About 4.6 billion won has been saved with applying to the harbor construction project with using the VE method proposed in this paper. The study gives the direction of VE to be accomplished efficiently in the similar project.

• Journal of the Korean GEO-environmental Society
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• v.7 no.4
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• pp.53-62
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• 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 Rural Planning
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• v.30 no.2
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• pp.13-24
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• 2024

This study conducts an analysis of social media big data pertaining to island tourism resources, aiming to discern the diverse forms and categories of island tourism favored by consumers, ascertain predominant resources, and facilitate objective decision-making grounded in scientific methodologies. To achieve this objective, an examination of blog posts published on Naver from 2022 to 2023 was undertaken, utilizing keywords such as 'Island tourism', 'Island travel', and 'Island backpacking' as focal points for analysis. Text mining techniques were applied to sift through the data. Among the resources identified, the port emerged as a significant asset, serving as a pivotal conduit linking the island and mainland and holding substantial importance as a focal point and resource for tourist access to the island. Furthermore, an analysis of the disparity between existing island tourism resources and those acknowledged by tourists who actively engage with and appreciate island destinations led to the identification of 186 newly emerging resources. These nascent resources predominantly clustered within five regions: Incheon Metropolitan City, Tongyeong/Geoje City, Jeju Island, Ulleung-gun, and Shinan-gun. A scrutiny of these resources, categorized according to the tourism resource classification system, revealed a notable presence of new resources, chiefly in the domains of 'rural landscape', 'tourist resort/training facility', 'transportation facility', and 'natural resource'. Notably, many of these emerging resources were previously overlooked in official management targets or resource inventories pertaining to existing island tourism resources. Noteworthy examples include ports, beaches, and mountains, which, despite constituting a substantial proportion of the newly identified tourist resources, were not accorded prominence in spatial information datasets. This study holds significance in its ability to unearth novel tourism resources recognized by island tourism consumers through a gap analysis approach that juxtaposes the existing status of island tourism resource data with techniques utilizing social media big data. Furthermore, the methodology delineated in this research offers a valuable framework for domestic local governments to gauge local tourism demand and embark on initiatives for tourism development or regional revitalization.

• Journal of the Korean Geotechnical Society
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• v.39 no.4
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• pp.45-54
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• 2023

The settlement prediction during the design phase is primarily conducted using theoretical methods. However, measurement-based settlement prediction methods that predict future settlements based on measured settlement data over time are primarily used during construction due to accuracy issues. Among these methods, the hyperbolic method is commonly used. However, the existing hyperbolic method has accuracy issues and statistical limitations. Therefore, a weighted nonlinear regression hyperbolic method has been proposed. In this study, two weighting methods were applied to the weighted nonlinear regression hyperbolic method to compare and analyze the accuracy of settlement prediction. Measured settlement plate data from two sites located in Busan New Port were used. The settlement of the remaining sections was predicted by setting the regression analysis section to 30%, 50%, and 70% of the total data. Thus, regardless of the weight assignment method, the settlement prediction based on the hyperbolic method demonstrated a remarkable increase in accuracy as the regression analysis section increased. The weighted nonlinear regression hyperbolic method predicted settlement more accurately than the existing linear regression hyperbolic method. In particular, despite a smaller regression analysis section, the weighted nonlinear regression hyperbolic method showed higher settlement prediction performance than the existing linear regression hyperbolic method. Thus, it was confirmed that the weighted nonlinear regression hyperbolic method could predict settlement much faster and more accurately.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.845-856
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• 2017

In the long railway tunnel, in order to secure safety in case of fire, it is required a emergency station. However, there is no standard or research results on smoke exhaust method and exhaust flow rate in emergency station, so it is necessary to study the smoke exhaust system for emergency station. In this study, we are created a numerical analysis model for emergency station where the evacuation cross passage connected to the service tunnel or the relative tunnel was installed at regular intervals (40 m intervals). And the fire analysis are carried out by varying the fire intensity (15, 30MW), the smoke exhaust method (only air supply, forced air supply and exhaust, forced air exhaust only), and the air flow rate (7, 14, $40m^3/s$). From the results of fire analysis, temperature and CO concentration are analyzed and ASET based on the limit temperature are compared at various condition. As a result, in the case with fire intensity of 15 MW, it is shown that a sufficiently safe evacuation environment can be ensured by applying forced air supply and exhaust method or forced air exhaust only method when the air flow rate is $7m^3/s$ above. In case of fire intensity of 30 MW, it is impossible to maintain the safety evacuation environment for more than 900 seconds when the exhaust air volume is below $14m^3/s$. And when the air flow rate is $40m^3/s$, the exhaust port is disposed at the side portion of the upper duct, which is most advantageous for securing the temperature-based safety.

• Journal of the Korean Geosynthetics Society
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• v.20 no.4
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• pp.85-93
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• 2021

The seventy percentage of Korean Peninsular is covered by the mountainous area, and the depth of west sea and south sea is relatively shallow. Therefore, a large scale land reclamation from the sea has been implemented for the construction of industrial complex, residental area, and port and airport facilities. The common problem of reclaimed land is consisted of soft ground, and hence it has low load bearing capacity as well as excessive settlement upon loading on the ground surface. The hollow concrete block has been used to reinforce the loose and soft foundation soil where the medium-high apartment or one-story industrial building is being planned to be built. Recently the earthquakes with the magnitude of 4.0~5.0 have been occurred in the west coastal and southeast coastal areas. Lee (2019) reported the advantages of hollow concrete block reinforced shallow foundation through the static laboratory bearing capacity tests. In this study, the dynamic behavior of hollow concrete block reinforced sandy ground with filling the crushed stone in the hollow space has been investigated by the means of shaking table test with the size of shaking table 1000 mm × 1000 mm. Three types of seismic wave, that is, Ofunato, Hachinohe, Artificial, and two different accelerations (0.154 g, 0.22 g) were applied in the shaking table tests. The horizontal displacement of structure which is situated right above the hollow concrete block reinforced ground was measured by using the LVDT. The relative density of soil ground are varied with 45%, 65%, and 85%, respectively, to investigate the effectiveness of reinforcement by hollow block and measured the magnitude of lateral movement, and compared with the limit value of 0.015h (Building Earthquake Code, 2019). Based on the results of shaking table test for hollow concrete block reinforced sandy ground, honeycell type hollow block gives a large interlocking force due to the filling of crushed stone in the hollow space as well as a great interface friction force by the confining pressure and punching resistance along the inside and outside of hollow concrete block. All these factors are contributed to reduce the great amount of horizontal displacement during the shaking table test. Finally, hollow concrete block reinforced sandy ground for shallow foundation is provided an outstanding reinforced method for medium-high building irrespective of seismic wave and moderate accelerations.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.1
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• pp.1-12
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• 2021

To investigate the effect of freshwater discharge on the seawater circulation in the semi-closed harbor, a 3-D hydrodynamic model was applied to the International Ferry Terminal (IFT). The model run is conducted for 45 days (from May 15 to June 30, 2020), and the reproducibility of the model for time-spatial variability of current velocity and salinity was verified by comparison with model results and observation data. There are two sources of freshwater towards inside of the IFT: Han River and water reservoir located in the eastern part of IFT. In residual current velocity results, the two-layer circulation (the seaward flow near surface and the landward flow near bottom)derived from the horizontal salinity gradient in only considering the discharge from a Han River is more developed than that considering both the Han River and water reservoir. This suggests that the impact of freshwater from the reservoir is greater in the IFT areas than that from a Han River. Additionally, the two-layer circulation is stronger in the IFT located in southern part than Incheon South Port located in northern part. This process is formed by the interaction between tidal current propagating into the port and freshwater discharge from a water reservoir, and flow with a low salinity (near 0 psu) is delivered into the IFT. This low salinity distribution reinforces the horizontal stratification in front of the IFT, and maintains a two-layer circulation. Therefore, local sources of freshwater input are considered to estimate for mass transport process associated with the seawater circulation within the harbor and It is necessary to perform a numerical model according to the real-time freshwater flow rate discharged.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.846-853
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• 2016

This study prioritizes Noxious Liquid Substances (NLS) transported by sea via a risk-based database containing 596 chemicals to prepare against NLS incidents. There were 158 chemicals transported in Korean waters during 2014 and 2015, which were prioritized, and then chemicals were grouped into four categories (with rankings of 0-3) based on measures for preparedness against incident. In order to establish an effective preparedness system against NLS spill incidents on a national scale, a compiling process for NLS chemicals ranked 2~3 should be carried out and managed together with an initiative for NLS chemicals ranked 0-1. Also, it is advisable to manage NLS chemicals ranked 0-1 after considering the characteristics of NLS specifically transported through a given port since the types and characteristics of NLS chemicals relevant differ depending on the port. In addition, three designated regions are suggested: 1) the southern sector of the East Sea (Ulsan and Busan); 2) the central sector of the South Sea (Gwangyang and Yeosu); and 3) the northern sector of the West Sea (Pyeongtaek, Daesan and Incheon). These regions should be considered special management sectors, with strengthened surveillance and the equipment, materials and chemicals used for pollution response management schemes prepared in advance at NLS spill incident response facilities. In the near future, the risk database should be supplemented with specific information on chronic toxicity and updated on a regular basis. Furthermore, scientific ecotoxicological data for marine organisms should be collated and expanded in a systematic way. A system allowing for the identification Hazardous and Noxious Substances (HNS) should also be established, noting the relevant volumes transported in Korean waters as soon as possible to allow for better management of HNS spill incidents at sea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.1-7
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• 2005

Tidal flats have been regarded to carry out transformation and removal of land-derived organic matter, and this purifying capability of organic matter by tidal flats is one of very important reasons for their conservation. However, integral biogeochemical studies on production and decomposition of organic matter by benthic microbes in tidal flats have been absent in Korea, although the information is indispensable to quantification of the purifying capability. Our major goals in this multidisciplinary research were to understand major biogeochemical processes and rates mediated by diverse groups of microbes dominating material cycles in the tidal flats, and to assess the contribution of benthic microbes to removal of organic matter and nutrients in the tidal flats. Our study sites were Ganghwa and Incheon north-port tidal flats that had been regarded as naturally well reserved and organically polluted, respectively. Our research group measured over 3 years primary production, biomass and community structure of primary producers, abundance and production of bacteria, enzyme activities, distribution of protozoa and protozoan grazing rates, rates of denitrification and sulfate reduction, early sediment diagenesis, primary production and respiration based on oxygen microelectrode. We analyzed major features of each biogeochemical process and their interactions. The results are compiled in the following articles in this special issue: An (2005), Hwang and Cho (2005), Mok et at. (2005), Na and Lee (2005), Yang et at. (2005), and Yoo and Choi (2005).

• Journal of Nutrition and Health
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• v.41 no.1
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• pp.89-99
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• 2008

This study was conducted to investigate the main and side dish preference of food with 681 children (145 of kindergarten, 300 of children, 236 of adolescences) in Seoul and Gyeonggi area using questionnaires. Regarding preference of the staple foods, it was shown that all group had the highest preferences for boiled rice, The kindergarten period prefer Jajangmyen the most, children and adolescences like spaghetti (p<0.05). For breads, the kindergarten preferred cakes the most, the middle years and the adolescences preferred pizza. Regarding preference of soups, it represents the kindergarten liked seaweed soup, the children and adolescences liked sollongt'ang (p<0.05). For pot stew, the kindergarten preferred bean-paste pot stew the most, the children with parents' income level less than 4 million won preferred Kim-chi stew, the middle years with parents' income level equal or greater than 4 million won preferred beanpaste pot stew and all adolescences preferred Kim-chi pot stew (p<0.05). Stewed beef with soy sauce was preferred the most by all ages. For pan-fried foods, the kindergarten with parents' income level less than 4 million won preferred pan-fried spicy port the most, the kindergarten with parents' income level equal or greater than 4 million won preferred pan-fried anchovy the middle years preferred pan-fried spicy pork, the adolescences with parents' income level less than 4 million won preferred pan fried Kim-chi the most (p<0.05). And for vegetable dish, all age groups preferred seasoned bean sprouts and Chinese cabbage Kim-chi the most which they can easily see on their tables.