• Title/Summary/Keyword: Coastal facility

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A Study on the Creation and Use of Nokgakseong and Underwater Wooden Fence (조선시대 녹각성과 수중목책의 조성 및 활용에 관한 연구)

  • SHIM Sunhui;KIM Choongsik
    • Korean Journal of Heritage: History & Science
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    • v.56 no.4
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    • pp.230-246
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    • 2023
  • The wooden fence(木柵), which began to appear in the Bronze Age and is presumed to be the oldest defense facility in human history, was used as a fortress for the purpose of further strengthening military defense functions until after the Japanese Invasion of Korea in 1592 in the Joseon Dynasty(壬辰倭亂). As it was established as the concept of a fortress or a fence installed outside a fence castle(城柵) or barracks fence(營柵), its importance as an essential facility for defense was further highlighted. This study is the result of exploring wooden fence that were used as official facilities during the Joseon Dynasty, focusing on literature surveys such as 『Annals of the Joseon Dynasty』 and 『New Jeungdonggukyeojiseungram』 In this study, in particular, the conclusion of this study is as follows, focusing on the use and function of Nokgakseong(鹿角城), underwater wooden fence, installation methods, and materials of wooden fences, is as follows. The conclusions of this study, which focused on the materials of the wooden fence, are as follows. First, as invasions by foreign enemies became more frequent in the late Goryeo and early Joseon Dynasty, wooden fences played a major role as a major out-of-castle defense facility((防禦施設). In addition, wooden fences were modified and installed into various types such as wooden fences(木柵城), Nokgakseong, a fence made up of large branches in the shape of a deer antler, and underwater wooden fences(水中木柵) according to the circumstances of the times, government policy, and location environment. Second, wooden fences were installed in strategic locations in defense facilities for military purposes, such as mountain fortress(山城), fortresses(營), camps(鎭), forts(堡), and castles(邑城) in strategic locations, and were used for defense in case of emergency. According to the urgency of farming, it was installed in accordance with the non-farming season, when it is easy to mobilize manpower to avoid the busy farming season. The size of the wooden fence of the Joseon Dynasty, which are confirmed through literature records, was converted into Pobaekchuk(布帛尺), and the circumference was very diverse from 4,428chuk(2,066m) to 55chuk(25m). Third, Nokgakseong is an efficient combat support facility that is more aggressive than a general wooden fence, and the records of Nokgakseong in the Annals of the Joseon Dynasty appeared during the King Sejong period the record was 20 times, the most. By region, it was found that it was mainly installed in coastal rugged areas such as Pyeongan and Hamgildo(12), which are the 6-jin areas of the 4th Army. Fourth, in the early 15th century, as the royal court established a maritime defense strategy for the coastal area of the southern coast, after the Sampo Invasion(三浦倭亂), riots by Japanese settlers in Sampo in 1510, major military posts including eupseong(邑城), camps, and forts were established. The installation of underwater barriers around various government facilities rapidly increased as a defense facility to block the warships of Japanese pirates around various government facilities. Fifth, between the 15th and 17th centuries before and after the Japanese Invasion of Korea in Sampo, underwater fences were installed in the Southern coast and Ganghwa Island. In particular, in the 15th century, underwater fences were intensively installed in coastal areas of Gyeongsangnam-do, such as Jepo. Pine trees and Oaks are the main materials used for underwater fences, but other materials such as Oldham's meliosma, Loose-flower hornbeam and The vines of arrowroots were also used as materials for wooden fences.

Comparison of Numerical Solutions by TVD Schemes in Simulations of Irregular Waves Propagating over a Submerged Shoal Using FUNWAVE-TVD Numerical Model (FUNWAVE-TVD 수치모형을 이용한 수중천퇴를 통과하는 불규칙파의 수치모의에서 TVD 기법들에 의한 수치해 비교)

  • Choi, Young-Kwang;Seo, Seung-Nam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.4
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    • pp.143-152
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    • 2018
  • Numerical convergence and stability of TVD schemes have been applied in the FUNWAVE-TVD model were compared. The fourth order accurate MUSCL-TVD scheme using minmod limiter suggested by Yamamoto and Daiguji (1993), the fourth order accurate MUSCL-TVD scheme using van-Leer limiter suggested by Erduran et al. (2005) and the second order accurate MUSCL-TVD scheme using van-Leer limiter in Zhou et al. (2001) were compared. Comparisons of the numerical scheme were conducted with experimental data of Vincent and Briggs irregular wave experiments. In comparison with the fourth order accurate scheme using van-Leer limiter, the fourth order accurate scheme using minmod limiter is less dissipative but required lower CFL condition for stable numerical solution. On the other hand, the scheme using van-Leer limiter required smaller resolution spatial grid due to numerical dissipation, but relatively higher CFL condition can be used compared to the scheme using minmod limiter. In the breaking wave experiments which were conducted using high resolution spatial grid to reduce numerical dissipation, the characteristic of the schemes can be clearly observed. Numerical instabilities and blow-up of the numerical solutions were found in the irregular wave breaking simulation with the scheme using minmod limiter. However, the simulation can be completed with the scheme using van-Leer limiter, but required low CFL condition. Good agreements with the observed data were also observed in the results using van-Leer limiter.

Comparison of Wave Stresses in the Eulerian Nearshore Current Models (오일러형 해빈류 모형의 파랑응력 비교)

  • Ahn, Kyungmo;Suh, Kyung-Duck;Chun, Hwusub
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.6
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    • pp.350-362
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    • 2017
  • The Eulerian nearshore current model is more advantageous than the Lagrangian model in the way that numerical results from the Eulerian model can be directly compared with the measurements by the stationary equipment. It is because the wave mass flux is not included in the computed mass flux of Euleran nearshore current model. In addition, the Eulerian model can simulate the longshore currents with depth varying parabolic profile. However, the numerical models proposed by different researcher have different forms of the wave stress terms. For example, wave stresses in Newberger and Allen's (2007) model is constant over the depth, while those of Chun (2012) are vertically distributed. In the present study, these wave stress terms were compared against Hamilton et al.'s (2001) laboratory experiments to see the effects of different wave stress terms performed on the computation of nearshore currents.

Analysis on Non-Market Benefit of Port Re-Modeling Factor Using AHP (AHP를 이용한 항만 리모델링 비시장적 편익요인 분석연구)

  • Yang, Chang-Ho;Yeo, Gi-Tae;Jung, Hyun-Jae;Kim, Ho-Kyun;Son, Yoo-Lee
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.23 no.1
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    • pp.57-62
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    • 2011
  • At this point that port industry brings a new change as the concept of 'Green Logistics' appears, studies on an economic analysis of existing port Re-modeling have normally been conducted focused on market value factors such as Benefit-Cost analysis, On the other hand, there have been few studies on the analysis of Non-market value factors such as environmental value. Therefore, the purpose of this study is aimed to establish a Feasibility analysis model of Incheon inner port Re-modeling in the aspect of Non-market Benefit Factors classified by related factors such as, marine environment, waterfront facility and welfare of users by using AHP methodology based on the extracted result through previous studies.

Facilities Analysis of Laver Cultivation Grounds in Korean Coastal Waters Using SPOT-5 Images in 2005 (SPOT-5 위성영상에 의한 2005년 한국 연안 김 양식장의 시설현황 분석)

  • Yang Chan-Su;Park Sung-Woo
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.9 no.3
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    • pp.168-175
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    • 2006
  • The cultural grounds of lave r have been surveyed using SPOT-5 satellite images. The facilities of laver cultivation area in the coastal waters of Korea were calculated. 10 m resolution multispectral images of SPOT-5 are adopted for the southern are a of Jebu Island, Hwaseong city to develop an automatic detection approach of laver nets that consists of the following: band difference technique, canny edge detector and morphological analysis: The number of satellite-based facilities was relatively high as compared with the licensed number in 2005, 676,749 chaek and 572,745 chaek(柵, unit of measure for laver farm), respectively. The ratio of a law abiding facility was very low at 52.9%. These data could be applied to control its national production keeping a stable market price for the government body.

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Study of the Optimal Mesh Size for a Safety Net for Preventing Falls from Wave-dissipating Blocks (소파블록 낙상사고 방지를 위한 안전망 그물코 크기 산정에 관한 연구)

  • Yoon, Han-Sam;Kim, Min-Su;Jang, Sung-Chul;Lee, Hieung-Sin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.7
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    • pp.834-840
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    • 2019
  • Recently, due to increased tourism and leisure activities, falls by fishers from coastal wave-dissipating blocks (breakwaters) in Korea have been rising. We investigated the optimal mesh size for use in safety nets designed to cover Tetrapod (TTP) breakwaters to prevent casualties from falls. This is a prerequisite for considering the scale and economics of safety net facilities. The optimal mesh size was determined based on the fisher gender and age, and the bodily features of Koreans. The optimal mesh size was found to be 18.6-27.0 cm, derived based on the femoral length and chest circumference.

Effect of oxygen micro-bubble for the temperature and oxygen concentrations of fish farming facility (미세기포 액화산소가 가두리양식장의 수온 및 산소농도에 미치는 영향)

  • AN, Na;LEE, Jeong Kyu;LEE, Jun Seok;CHOI, Keun-Hyung
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.56 no.4
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    • pp.407-418
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    • 2020
  • Mass mortality of mariculture fish due to high summer temperatures is a major issue in the mariculture industry in many coastal waters of Korea, yet measures to mitigate the impact are generally limited. We injected a micro-bubble of liquefied oxygen into the bottom of rockfish cages (about 6-8 m deep) in order to maximize the dispersal of micro-bubbled seawater and reduce fish mortality. The injection of low-temperature oxygen in micro-bubbles lowered the water temperature at the injection area by as much as 1℃ and increased dissolved oxygen concentration by 0.5 ppm. In early August, following a week with persistent high water temperature (above 28.5℃), there was an increase in fish mortality despite the micro-bubble system, which resulted in approximately 7% death of the total introduced fish population. However, this mortality appeared to be much lower than mortality reported in a neighboring mariculture facility (approximately 50% mortality). We also estimated the volume that can be recirculated with pumped seawater using a micro-bubble system. We suggest that this approach of injecting liquefied oxygen through a micro-bubble system may reduce fish mortality during high temperature periods.

A Study on the Hazard and Risk Analysis of Hospital in Korea - Focused on Local Medical Centers (의료기관의 위험도 분석 조사 - 지역공공의료원을 중심으로)

  • Kim, Youngaee;Song, Sanghoon;Lee, Hyunjin;Kim, Taeyun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.28 no.4
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    • pp.31-39
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    • 2022
  • The purpose of this study is to analyse the hazard risk by examining the magnitude and severity of each type of hazard in order to mitigate and prepare for disasters in medical facilities. Methods: The hazard risk analysis for hazard types was surveyed for team leaders of medical facilities. The questionnaire analyzed data from 27 facilities, which were returned from 41 Local Medical Centers. Results: When looking at the 'Risk' by category type of hazard, the influence of health safety and fire/energy safety comes first, followed by natural disaster, facility safety, and crime safety. On the other hand, as for 'Magnitude', facility safety and crime safety come first, followed by health safety, fire/energy safety, and natural disasters. Most of the top types of disaster judged to have high hazard in medical facilities are health types. The top five priorities of hazard in medical facilities, they are affected by the geographical and industrial conditions of the treatment area. In the case of cities, the hazard was found to be high in the order of infectious disease, patient surge, and wind and flood damage. On the other hand, in rural areas, livestock diseases and infectious diseases showed the highest hazard. In the case of forest areas, the hazard was high in the order of wildfire, fire accident, lightning, tide, earthquake, and landslide, whereas in coastal areas of industrial complexes, the hazard was high due to fire, landslide, water pollution, marine pollution, and chemical spill accident. Implications: Through the research, standards will be established for the design of hospitals with disaster preparedness, and will contribute to the preparation of preemptive measures in terms of maintenance.

Numerical Model Application for Analysis of Flood Level Mitigation due to Retention-Basin (강변저류지 홍수위 저감효과 분석을 위한 수치모형 적용)

  • Cho, Gilje;Rhee, Dong Sop;Kim, Hyung-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.1
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    • pp.495-505
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    • 2014
  • The retention basin is a river-facility for the flood mitigation by storing the river flow temporarily. The new 3 retention basins are installed in these regions YeoJu, NaJu, YoungWol by the Large River Management Project. In this study, 1D and 2D numerical flow simulation are conducted to evaluate the reduction effect of the peak flood stage for the YeoJu retention basin. HEC-RAS and FLDWAV models are used for 1D simulation with the option of retention basin. CCHE2D model is used for 2D simulation with the same hydrograph used in 1D simulation. It is verified that the peak flood stage is reduced very largely about 0.13 m near the overtopping section of the levee in 1D simulation. It is verified that the peak flood stage is reduced very largely about 0.20 m at the upstream-end of the simulated reach in 2D simulation. 2D simulation for the retention basin is more reasonable because physical characteristics of topography in the model, and also more advantageous for the evaluation of the flow characteristics of the in- and outside of the retention basin on the results of simulation of this study.

Performance of structures and infrastructure facilities during an EF4 Tornado in Yancheng

  • Tao, Tianyou;Wang, Hao;Yao, Chengyuan;Zou, Zhongqin;Xu, Zidong
    • Wind and Structures
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    • v.27 no.2
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    • pp.137-147
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    • 2018
  • Heavy damages to properties with attendant losses were frequently caused by tornadoes in recent years. This natural hazard is one of the most destructive wind events that must be fully studied and well understood in order to keep the safety of structures and infrastructure facilities. On June 23, 2016, a severe tornado, which is an Enhanced Fujita (EF) 4 storm, occurred in the rim of a coastal city named as Yancheng in China. Numerous low-rise buildings as well as facilities (e.g., transmission towers) were destroyed or damaged. In this paper, damages to structures and infrastructure facilities by the severe tornado are reviewed. The collapses of residential buildings, industrial structures and other infrastructure facilities are described. With an overview of the damages, various possible mechanisms of the collapse are then discussed and utilized to reveal the initiation of the damage to various facilities. It is hoped that this paper can provide a concise but comprehensive reference for the researchers and engineers to help understand the tornado effects on structures and expose the vulnerabilities that need to be improved in current wind-resistant design practices.