• Title/Summary/Keyword: Construction Periods

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Development of Complementary Mild-slope Equation for Stream Function Over Permeable Bed (투수층에 적용 가능한 흐름함수방식의 확장형 완경사방정식의 개발)

  • Kim, Gunwoo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.6
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    • pp.758-765
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    • 2016
  • In this study, wave damping due to a permeable bed of finite depth was modelled using a complementary mild-slope equation for stream function. The energy dissipating term in the mild-slope equation was presented in terms of stream function. In order to prevent re-reflection of reflected waves along the outer boundary, a delta-function-shaped source function was derived to generate a wave in a computational domain. Numerical experiments were conducted to measure the reflection coefficient of waves over a planar slope for various incident wave periods. The numerical result of the proposed model was compared with that of an integral equation method, showing good agreement in general. However, the proposed model showed relatively higher transmission rate for the larger permeability and the longer wavelength.

Experimental investigation of long-term characteristics of greenschist

  • Zhang, Qing-Zhao;Shen, Ming-Rong;Ding, Wen-Qi;Jang, Hyun-Sic;Jang, Bo-An
    • Geomechanics and Engineering
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    • v.11 no.4
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    • pp.531-552
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    • 2016
  • The greenschist in the Jinping II Hydropower Station in southwest China exhibits continuous creep behaviour because of the geological conditions in the region. This phenomenon illustrates the time-dependent deformation and progressive damage that occurs after excavation. In this study, the responses of greenschist to stress over time were determined in a series of laboratory tests on samples collected from the access tunnel walls at the construction site. The results showed that the greenschist presented time-dependent behaviour under long-term loading. The samples generally experienced two stages: transient creep and steady creep, but no accelerating creep. The periods of transient creep and steady creep increased with increasing stress levels. The long-term strength of the greenschist was identified based on the variation of creep strain and creep rate. The ratio of long-term strength to conventional strength was around 80% and did not vary much with confining pressures. A quantitative method for predicting the failure period of greenschist, based on analysis of the stress-strain curve, is presented and implemented. At a confining pressure of 40 MPa, greenschist was predicted to fail in 5000 days under a stress of 290 MPa and to fail in 85 days under the stress of 320 MPa, indicating that the long-term strength identified by the creep rate and creep strain is a reliable estimate.

A Study of Architectural Features on Keunsaemal Asan Sinhang-ri (Birthplace of Former President Yun Bo-seon Village) (아산 신항리 큰새말 (윤보선 전 대통령 생가마을) 건축특성 조사연구)

  • Lee, Wang-Kee;Kang, In-Gu;Moon, Tae-Mo;Song, Yeon-Ah
    • Journal of architectural history
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    • v.19 no.2
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    • pp.7-20
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    • 2010
  • Keunsemal, Sinhang-ri, Dunpo-myeon Asan-si,Chungcheongnam-do is where the former President of Korea, Yun, Bosun was born. The houses of Yun, Il-Sun, Yun, Je-Hyung, Yun, Seung-Gu, and where the former President Yun was born are designated as cultural assets by the Korean government. The three houses of the Yuns are located in the center of the village and the size is much different from regular houses since they were created as large scale house of nobilities during the Chosun Dynasty. Along with the three Yun houses and other houses in the village show a great history and tradition of the history and modern times. Unlike other traditional village arrangement, this village was created during the end of Chosun Dynasty and extended into the modern times. From the village, you can see the changes in architecture within the 200 years from traditional Korean-style houses to modern houses. This investigation is a research / analysis of the architectural characteristics of Keunsemal, Sinhang-ri, Asan-si. People can observe changes in the different types of architectural forms of houses based on the history of Korea and time periods. Within the village, there are large scale house of nobilities which were built during the late Chosun Dynasty, common people's houses, farmhouses which were built during the modern times, common people's houses during the industrialization period, and modern houses with backyards. The village of Keunsemal, Sinhang-ri, Asan-si is a very special cultural asset for Korea because the houses in the village show a clear architectural process of change in styles of houses for Korean history.

Overview of Seismic Loads and Application of Local Code Provisions for Tall Buildings in Baku, Azerbaijan

  • Choi, Hi Sun;Sze, James;Ihtiyar, Onur;Joseph, Leonard
    • International Journal of High-Rise Buildings
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    • v.3 no.1
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    • pp.65-71
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    • 2014
  • Baku, the capital of Azerbaijan, has seen a boom in construction in recent years. The old Baku city has been rapidly transforming into a new hub of high-rise buildings and lively cultural centers hosting the Euro Vision Song Contest in 2012 and European Games in 2015. A major population shift to Baku from its suburbs and the countryside has resulted in the doubling of Baku's population in the 4 years between 2009 and 2013. As of January 2013, Baku's population reached four million people, 43% of the citizens in Azerbaijan according to The State Statistical Committee of Azerbaijan. With this trend, the city needs more high-rise buildings to accommodate rapidly increasing demands for more housing and business space. Until the Azerbaijan Seismic Building Code was published in 2010 and became effective, many different seismic criteria, in terms of building codes and seismic intensities, were used for all new high-rise projects in Baku. Some designers used the SNIP (Russian) code with seismic level 9 or level 8 with 1 point penalty. Others used the Turkish code with Seismic Zone 1, UBC 97 with Zone 2 through 4, or IBC with Sa = 0.75 g through 1.0 g. The seismic intensity is now clarified with the Azerbaijan Seismic Building Code. However, the Azerbaijan Seismic Building Code is appropriate for low-rise buildings applications but may be inappropriate for high-rise project applications. This is because the code-defined response spectrum yields unrealistically conservative seismic forces for high-rise buildings with long periods, as compared to those determined by other internationally accepted building codes. This paper provides observations and recommendations for code-based seismic load assessment of high-rise buildings in the Baku area.

A Study on the Planning of Improved-Hanok - Focused on Jeon-Nam Province - (생활한옥의 평면구성에 관한 연구 - 전남지방을 중심으로 -)

  • Kang, Man-Ho;Lee, Woo-Won;Jeong, Hun;Joo, Seok-Joong
    • Journal of the Korean housing association
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    • v.20 no.3
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    • pp.11-18
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    • 2009
  • The purpose of this study is to propose a method of developing an improved Hanok. To achieve this, an investigation was carried out on the factors of the main floor plan in the improved Hanok development and an interview was conducted with residents who live in the improved Hanok development. The conclusions obtained through this study are as follows: First, The shape of 一 was marked at the highest in the Korean traditional plan types such as 一, ㄱ and 田. It is considered that this reduces the cost of construction by simplifying the structure of the roof. Second, the size was consisted of $5{\times}3$ Kan, the Korean traditional module that determines the number of columns and expresses the position of the inner wall. However, the Kan measure ments for the bathroom and multi-purpose room differed. Third, 57.6% of the 2 bedroom units were investigated. However, 60% of the residents preferred 3 bedroom units. Fourth, the results of the relationship between the living room and the kitchen showed that the residents preferred L+DK type to LDK type by 54.2% and 45.8% respectively. Fifth, the residents preferred a bathroom constructed next to the bedroom because they considered that the improved Hanok development would be used as an Inn during holiday periods. Moreover, they desired a plan where the bathroom could be directly entered from the outside. Sixth, the design for the improved Hanok development should have a suitable multipurpose-room because 72.5% of the residents have extended their house to accommodate such a room. Seventh, 61% of the improved Hanok units had an entrance space, which does not exist in Korean traditional houses. For this reason, the Korean traditional floor (: the Maru) was avoided due to its inconvenience.

The Periodic Characteristics of Landscape Facilities in Apartment Sites - Specially Focused on Apartment Sites in Cheongju City - (아파트 단지 조경시설물의 시대적 변천 특성 - 청주시 아파트 단지를 대상으로 -)

  • Hong, Seong-Rae;Jeong, Dae-Young;Shim, Sang-Ryul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.6
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    • pp.63-75
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    • 2009
  • This study carried out to analysis the characteristics of periodic changes of landscape facilities with the apartment sites in Cheongju City. The construction periods were divided into the introduction stage (the 1980s), the development stage (the 1990s), and the maturity stage (after 1999). As for the apartment sites constructed in the introduction stage (the 1980s), their landscape facilities were restricted to play and resting facilities. Some of them even were constructed without rest facilities. Since the focus was on the affluent supply of houses in the 1980s, they put a greater emphasis on quantity than quality. Entering the development stage in the 1990s, they started to pave the sidewalks and driveways separately within the apartment sites and build parking lots underground. After 1999, they entered the maturity stage, where the outside spaces of apartment sites began to reflect environment-friendly designs and the initiatives to improve residential environments. The major causes behind the introduction of high-grade materials in landscape facilities in the open spaces of apartment sites are the upgraded level of living standards and the diversified patterns of activities taking place in the open spaces. The environmental formative works were placed alongside waterscape spaces to create a beautiful and harmonious landscape.

A Study on BASINS/WinHSPF for Evaluation of Non-point Source Reduction Efficiency in the Upstream of Nam-Han River Watershed (BASINS/WinHSPF를 이용한 남한강 상류 유역의 비점오염원 저감효율평가)

  • Yoon, Chun-Gyeong;Shin, Ah-Hyun;Jung, Kwang-Wook;Jang, Jae-Ho
    • Journal of Korean Society on Water Environment
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    • v.23 no.6
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    • pp.951-960
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    • 2007
  • Window interface to Hydrological Simulation Program-FORTRAN (WinHSPF) developed by the United States Environmental Protection Agency (EPA) was applied to the upstream of Nam-Han river watershed to examine its applicability for loading estimates in watershed scale and to evaluate non-point source control scenarios using BMPRAC in WinHSPF. The WinHSPF model was calibrated and verified for water flow using Ministry of Construction and Transportation (MOCT, 3 stations, 2003~2005) and water qualities using Ministry of Environment (MOE, 5 station, 2000~2006). Water flow and water quality simulation results were also satisfactory over the total simulation period. But outliers were occurred in the time series data of TN and TP at some regions and periods. Therefore, it required more profit calibration process for more various parameters. As a result, all the study was performed within the expectation considering the complexity of the watershed, pollutant sources and land uses intermixed in the watershed. The estimated pollutant load for annual average about $BOD_5$, T-N and T-P respectively. Nonpoint source loading had a great portion of total pollutant loading, about 86.5~95.2%. In WinHSPF, BMPRAC was applied to evaluate non-point source control scenarios (constructed wetland, wet detention ponds and infiltration basins). All the scenarios showed efficiency of non-point source removal. Overall, the HSPF model is adequate for simulating watersheds characteristics, and its application is recommended for watershed management and evaluation of best management practices.

Prediction of Reservoir Sedimentation Patterns Using a Two-Dimensional Transport Model (2차원 유사운송모형을 이용한 저수지 퇴적분포유형의 추정)

  • 이봉훈;박창헌;박승우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.35 no.1
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    • pp.50-58
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    • 1993
  • The sedimentation patterns at a reservoir, important to the reservoir capacity curve were simulated using a depth averaged, two-dimensional sediment transport model, that is capable of depicting velocity distributions and sediment transportation. The Banweol reservoir, whose stage capacity relationships have been surveyed before and after the construction, was selected and the daily inflow rates and stages were simulated using a reservoir operation model(DI-ROM). The applicability of the transport model was tested from the comparisons of simulated sedimentation patterns to the surveyed results. The simulated inflow rates and water level fluctuations at the reservoir during twenty-one years from 1966 to 1986, showed that water levels exceeding 80 percent of the total capacity occurred for 70 percent of the periods and inflow rates less than 5000rn$^3$/day sustained for 54 percent of the spans. Dorminant flow directions were simulated from two streamflow inlets to the dam site. And simulated sediment concentrations were higher near the inlets and lower at the inside of the reservoir. Sediment was deposited heavily near the inlets, and portions of sediments were distributed along the flow paths within the reservoir. The comparisons between the simulation results and the surveyed depositions were partially matched. However, it was not possible to compare two results at the upper parts of the reservoir where dredging was carried out few times for the purpose of reservoir maintenance. This study demonstrates that sedimentation patterns within the reservoir are closely related to incoming sediment and flow rates, water level fluctuations, and flow circulation within the reservoir.

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Development of Infiltration System for Stormwater Management from Paved Area (포장지역 강우유출수 관리를 위한 침투도랑 기술개발)

  • Lee, Jeong-Yong;Maniquiz, Marla C.;Lee, So-Young;Kim, Lee-Hyung
    • Journal of Wetlands Research
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    • v.12 no.3
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    • pp.165-175
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    • 2010
  • Recently, various development projects have occurred due to rapid industrialization and urbanization. Both industry and population grew rapidly which causes a corresponding rise in pollution. The accumulated pollutants are washed-off during rainy days, highly degrading the water quality of the receiving water body. This is because a lot of non point source (NPS) pollutants were accumulated on the surface during dry periods. This research focuses on the development of Eco-Bio Filter (EBF) system that treats NPS pollutants. It is constructed at Kongju National University campus. The EBF is a type of a structured infiltration system that falls under the category of Low Impact Development (LID) hydrologic design practices. The monitoring of rain events was performed. It includes the development of design, the lessons learned from the post-construction testing and the improvements in the renovation made. After a series of monitoring, the MOE will use the results to apply the design to other areas in the country.

Is There a Stochastic Non-fundamental Trend in Korean Stock Price?: Inference under Transformed Error Correction Model (우리나라 주가에는 펀더멘털과 무관한 비정상 추세가 존재하는가?: 공적분 및 베버리지-넬슨 분해 접근)

  • Kim, Yun-Yeong
    • KDI Journal of Economic Policy
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    • v.35 no.2
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    • pp.107-131
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    • 2013
  • In this paper, we test and estimate the stochastic non-fundamental trend in Korean stock market. For this, following Kim (2011), we exploit that the long-run equilibrium stock price may be decomposed into fundamental and stochastic non-fundamental trends (i.e., the sum of dividend innovations and a part that are orthogonal with the dividend innovations) by using the Beveridge-Nelson decomposition and projections. In this VAR construction, there is an error correction mechanism through which stock prices converge to their long-run equilibrium, which also contain the stated stochastic non-fundamental trend as well as fundamental trend. The estimation and test results using yearly data from the Korea (1976-2012) indicated that fluctuations in stock prices during that period can be explained mainly not by the stochastic non-fundamental trend but by the dividend trend. However, during some periods like after Seoul Olympic Games, we may observe the non-fundamental trend affected to the stock price variation.

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