• Title/Summary/Keyword: Historical Analysis

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Comparative Analysis on Unit Price based on Historical Cost Data Estimating for Large and Small-scale Civil Engineering Works (대·소규모 토목공사의 실적공사비 비교 분석)

  • Hong, Sung Ho;Shin, Juyeoul;Kim, Chang Hak;Lee, Dong Wook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.4
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    • pp.1707-1718
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    • 2013
  • Historical cost data estimating system has been introduced since 2004 in the construction industry. Based on contract prices of past projects, this estimating system estimates construction cost according to work types. The Korea Institute of Construction Technology (KICT) announces the historical cost data twice a year annually. The unit price of a small construction project is higher than large construction project due to the increase on production cost per work unit, equipment and labor cost, etc. However, the historical cost data estimating system is applied to project estimation uniformly regardless the construction project's size. This study compared and analyzed the historical cost data of large and small construction project to indicate the problem of historical cost date estimating system. The study derived that the unit price of a small construction project is 21.8% higher than that of large construction project.

A Proposal for Use in Research Methodology of Traditional Medicine in East Asia - Historical Evidence-Based Medicine - (전통한의학 연구방법론의 현대화에 대한 소고(小考) - 역사적 근거중심의학에 대한 제언 -)

  • Eom, Seok-Ki;Kim, Se-Hyun;Choi, Won-Cheol
    • Journal of Korean Medical classics
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    • v.23 no.2
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    • pp.89-105
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    • 2010
  • Research methodology on Traditional Medicine in East Asia refers to logical thinking system, empirical positivism system and methodology of developing these knowledge systems. Logical thinking system of abstract concepts such as analogy or abduction and positivism system of reasonable explanation such as the five elements and their characteristic theory have been used in various ways empirically or in the form of humanities and knowledge system was developed through parallel structure of empirical positivism and exegetical studies. After the 16th century, evidence was required along with the tradition of putting emphasis on rationality, logicality and empirical positivism and characteristics of medical humanities can be found in emphasizing on medical ethics. Data that can be considered as structural review paper or meta analysis from original data of research on Traditional East Asian Medicine should be evaluated as historical evidence which is equivalent to specialist opinion, descriptive disease research, single case report or case series. Historical evidence based medicine is a research method using Historical evidence to selectively support data that are faithful to traditional theory with higher possibility to be used in future traditional east Asian medicine that links between traditional knowledge and scientific research methodology. Moreover, historical evidence based medicine tries to re-evaluate the value of traditional knowledge and ultimately, guides the direction of development of traditional medicine through scientific rationality based on history and culture.

Errors in Estimated Temporal Tracer Trends Due to Changes in the Historical Observation Network: A Case Study of Oxygen Trends in the Southern Ocean

  • Min, Dong-Ha;Keller, Klaus
    • Ocean and Polar Research
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    • v.27 no.2
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    • pp.189-195
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    • 2005
  • Several models predict large and potentially abrupt ocean circulation changes due to anthropogenic greenhouse-gas emissions. These circulation changes drive-in the models-considerable oceanic oxygen trend. A sound estimate of the observed oxygen trends can hence be a powerful tool to constrain predictions of future changes in oceanic deepwater formation, heat and carbon dioxide uptake. Estimating decadal scale oxygen trends is, however, a nontrivial task and previous studies have come to contradicting conclusions. One key potential problem is that changes in the historical observation network might introduce considerable errors. Here we estimate the likely magnitude of these errors for a subset of the available observations in the Southern Ocean. We test three common data analysis methods south of Australia and focus on the decadal-scale trends between the 1970's and the 1990's. Specifically, we estimate errors due to sparsely sampled observations using a known signal (the time invariant, temporally averaged, World Ocean Atlas 2001) as a negative control. The crossover analysis and the objective analysis methods are for less prone to spatial sampling location biases than the area averaging method. Subject to numerous caveats, we find that errors due to sparse sampling for the area averaging method are on the order of several micro-moles $kg^{-1}$. for the crossover and the objective analysis method, these errors are much smaller. For the analyzed example, the biases due to changes in the spatial design of the historical observation network are relatively small compared to the tends predicted by many model simulations. This raises the possibility to use historic oxygen trends to constrain model simulations, even in sparsely sampled ocean basins.

Practical seismic assessment of unreinforced masonry historical buildings

  • Pardalopoulos, Stylianos I.;Pantazopoulou, Stavroula J.;Ignatakis, Christos E.
    • Earthquakes and Structures
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    • v.11 no.2
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    • pp.195-215
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    • 2016
  • Rehabilitation of historical unreinforced masonry (URM) buildings is a priority in many parts of the world, since those buildings are a living part of history and a testament of human achievement of the era of their construction. Many of these buildings are still operational; comprising brittle materials with no reinforcements, with spatially distributed mass and stiffness, they are not encompassed by current seismic assessment procedures that have been developed for other structural types. To facilitate the difficult task of selecting a proper rehabilitation strategy - often restricted by international treaties for non-invasiveness and reversibility of the intervention - and given the practical requirements for the buildings' intended reuse, this paper presents a practical procedure for assessment of seismic demands of URM buildings - mainly historical constructions that lack a well-defined diaphragm action. A key ingredient of the method is approximation of the spatial shape of lateral translation, ${\Phi}$, that the building assumes when subjected to a uniform field of lateral acceleration. Using ${\Phi}$ as a 3-D shape function, the dynamic response of the system is evaluated, using the concepts of SDOF approximation of continuous systems. This enables determination of the envelope of the developed deformations and the tendency for deformation and damage localization throughout the examined building for a given design earthquake scenario. Deformation demands are specified in terms of relative drift ratios referring to the in-plane and the out-of-plane seismic response of the building's structural elements. Drift ratio demands are compared with drift capacities associated with predefined performance limits. The accuracy of the introduced procedure is evaluated through (a) comparison of the response profiles with those obtained from detailed time-history dynamic analysis using a suite of ten strong ground motion records, five of which with near-field characteristics, and (b) evaluation of the performance assessment results with observations reported in reconnaissance reports of the field performance of two neoclassical torsionally-sensitive historical buildings, located in Thessaloniki, Greece, which survived a major earthquake in the past.

Habitat Distribution of Tiger, Wolf, and Leopard in Joseonwangjosilok (조선왕조실록에 나타난 호랑이, 늑대, 표범의 서식분포)

  • Kim, Nam-Shin;Cha, Jin-Yeol;Lee, Seung-Eun;Lim, Chi-Hong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.4
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    • pp.35-45
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    • 2019
  • The objective of this study is to analyze habitat distribution on tiger, wolf, and leopard in Joseonwangjosilok. Nowaday, we only come to meet these kind of animals at the historical records because of haman-induced habitat encroachment. Historically, extinct animal became an object of game by people. So, we try to get distribution information for restoration on historical extinct animals. We made distribution map by constructing 402 counts on tiger(350), leopard(51) and wolf(1) recordsfrom 14th to Early 20th century for study. Analyzing historical materials, criteria for data analysis took into account objectivity, location information, accuracy for extinct animals. We carried out location identification of animals by using geocoding comparing with geographical name of the Joseon Dynasty period, topographic map of time under the rule of Japanese imperialism, present place name and historical materials. Database items are constructed 20 types for example appearance year of animal, population, location, damage, etc. As a result of analysis for appearance regions, tigers were recorded in capital area of higher density population intensively, and also were frequently seen at Daegu, Andong etc. Leopard and wolf were founded at regionally Gyeonggi-do and Jinju with limitation, relatively seen a few number. The reason of the appearance records like this, tiger prefer game of open and water-front area in near human residential area, there are lots of historical records such as 'Hosang'(mourning someone who killed by Tiger) and hunting. But leopard and wolf inhabit rocky area and dense forest, the reason why they made a few contact with human. Results of this are expect to be applicable restoration research for extinct animal by providing for populations, habitat environments and distribution information.

Evaluating effects of various water levels on long-term creep and earthquake performance of masonry arch bridges using finite difference method

  • Cavuslu, Murat
    • Geomechanics and Engineering
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    • v.31 no.1
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    • pp.31-52
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    • 2022
  • Investigating and evaluating the long-term creep behavior of historical buildings built on seismic zones is of great importance in terms of transferring these structures to future generations. Furthermore, assessing the earthquake behavior of historical structures such as masonry stone bridges is very important for the future and seismic safety of these structures. For this reason, in this study, earthquake analyses of a masonry stone bridge are carried out considering strong ground motions and various water levels. Tokatli masonry stone arch bridge that was built in the 10th century in Turkey-Karabük is selected for three-dimensional (3D) finite difference analyses and this bridge is modeled using FLAC3D software based on the three-dimensional finite difference method. Firstly, each stone element of the bridge is modeled separately and special stiffness parameters are defined between each stone element. Thanks to these parameters, the interaction conditions between each stone element are provided. Then, the Burger-Creep and Drucker-Prager material models are defined to arch material, rockfill material for evaluating the creep and seismic failure behaviors of the bridge. Besides, the boundaries of the 3D model of the bridge are modeled by considering the free-field and quiet boundary conditions, which were not considered in the past for the seismic behavior of masonry bridges. The bridge is analyzed for 6 different water levels and these water levels are 0 m, 30 m, 60 m, 70 m, 80 m, and 90 m, respectively. A total of 10 different seismic analyzes are performed and according to the seismic analysis results, it is concluded that historical stone bridges exhibit different seismic behaviors under different water levels. Moreover, it is openly seen that the water level is of great importance in terms of earthquake safety of historical stone bridges built in earthquake zones. For this reason, it is strongly recommended to consider the water levels while strengthening and analyzing the historical stone bridges.

Collapse mechanism estimation of a historical slender minaret

  • Nohutcu, H.;Hokelekli, E.;Ercan, E.;Demir, A.;Altintas, G.
    • Structural Engineering and Mechanics
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    • v.64 no.5
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    • pp.653-660
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    • 2017
  • The aim of this study is to accurately estimate seismic damage and the collapse mechanism of the historical stone masonry minaret "Hafsa Sultan", which was built in 1522. Surveying measurements and material tests were conducted to obtain a 3D solid model and the mechanical properties of the components of the minaret. The initial Finite Element (FE) model is analyzed and numerical dynamic characteristics of the minaret are obtained. The Operational Modal Analysis (OMA) method is conducted to obtain the experimental dynamic characteristics of the minaret and the initial FE model is calibrated by using the experimental results. Then, linear time history (LTH) and nonlinear time history (NLTH) analyses are carried out on the calibrated FE model by using two different ground motions. Iron clamps which used as connection element between the stones of the minaret considerably increase the tensile strength of the masonry system. The Concrete Damage Plasticity (CDP) model is selected in the nonlinear analyses in ABAQUS. The analyses conducted indicate that the results of the linear analyses are not as realistic as the nonlinear analysis results when compared with existing damage.

A Comparison of Construction Cost Estimation Using Multiple Regression Analysis and Neural Network in Elementary School Project

  • Cho, Hong-Gyu;Kim, Kyong-Gon;Kim, Jang-Young;Kim, Gwang-Hee
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.1
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    • pp.66-74
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    • 2013
  • In the early stages of a construction project, the most important thing is to predict construction costs in a rational way. For this reason, many studies have been performed on the estimation of construction costs for apartment housing and office buildings at early stage using artificial intelligence, statistics, and the like. In this study, cost data held by a provincial Office of Education on elementary schools constructed from 2004 to 2007 were used to compare the multiple regression model with an artificial neural network model. A total of 96 historical data were classified into 76 historical data for constructing models and 20 historical data for comparing the constructed regression model with the artificial neural network model. The results of an analysis of predicted construction costs were that the error rate of the artificial neural network model is lower than that of the multiple regression model.

A study on seismic behaviour of masonry mosques after restoration

  • Altunisik, Ahmet C.;Bayraktar, Alemdar;Genc, Ali F.
    • Earthquakes and Structures
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    • v.10 no.6
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    • pp.1331-1346
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    • 2016
  • Historical masonry structures have an important value for cultures and it is essential for every society to strengthen them and confidently transfer to the future. For this reason, determination of the seismic earthquake response, which is the most affecting factor to cause the damage at these structures, gain more importance. In this paper, the seismic earthquake behaviour of Kaya Çelebi Mosque, which is located in Turkey and the restoration process has still continued after 2011 Van earthquake, is determined. Firstly the dynamic modal analysis and subsequently the seismic spectral analysis are performed using the finite element model of the mosque constructed with restoration drawings in SAP2000 program. Maximum displacements, tensile, compressive and shear stresses are obtained and presented with contours diagrams. Turkish Earthquake Code and its general technical specifications are considered to evaluate the structural responses. After the analyses, it is seen that the displacements and compressive/shear stresses within the code limits. However, tension stresses exceeded the maximum values at some local regions. For this mosque, this is in tolerance limits considering the whole structure. But, it can be said that the tension stresses is very important for this type of the structures, especially between the stone and mortar. So, some additional strengthening solutions considering the originality of historical structures may be applicable on maximum tensile regions.

A Study on the Imjin War's Historical Materials with Multi-layer Network Analysis and Topic Modeling (다중 네트워크 분석과 토픽 모델링을 이용한 임진왜란 시기 사료에 관한 연구)

  • Cho, HyunChul;Song, Min
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.33 no.1
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    • pp.167-198
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    • 2022
  • Convergence science research is activated, and digital humanities research is also encouraged in humanities. Therefore, this study attempted to propose a experimental study that applies Text mining and Entitymetrics methods to historical materials. Annals of King Seonjo, revised Annals of King Seonjo, Miscellaneous Record of the War and Writings on Imjin War were used, also network analysis and DMR topic models were used to explore topic changes and common entities in historical sources. Through the results, it was possible to propose the availability of quantitative analysis for text data, presenting a timing change of a specific topic, and an undiscovered relationship between person entities.