• KIEAE Journal
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• v.16 no.3
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• pp.137-143
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• 2016

Purpose: Apartment housing should conduct a cyclic repair to keep and maintain the building performance since they are constructed. Therefore, the repair plan would be provided for long term period which explains the repair time, items and repair cost. Residents of apartment housing are responsible to pay for the repair activities. For repair cost, residents would reserve the money for repair little by little continuously until the required repair time because the repair cost takes a big burden for residents and lots of money a time. But, there is no systematic approach to provide the long term repair cost because it is no proper forecast of the repair cost to the upcoming repair time. In this study, it aimed at providing the monthly accumulation of the long term repair cost with the survey data in Seoul. Method: For these, the surveyed data are classified into 6 categories and number of data are 1,918. In addition, it developed the repair cost model for the 24 repair works and the cumulation function which is reflected with the each cost model. Result: This study are shown as follows : First, among the various estimation for the repair cost, the power function has a goodness of fit in statistics. Second, the monthly accumulation would be 12,840 won/household in size of $100,000m^2$ management area and $81.7won/m^2$ in size of the 1,000 household number during 40 years.

• KIEAE Journal
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• v.15 no.4
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• pp.85-90
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• 2015

Purpose: In design and planning Building Integrated Photovoltaic(BIPV) system can reduce cost by replacing building facade as construction material such as roofs, outer walls and windows as well as generating electricity. BIPV system should be applied at the early stage of architectural design. However, it is hard to decide whether using BIPV system or not for architects and builders who are not professional at BIPV system because performance of system is considerably influenced by types of module, installation position, installation methods and so on. It is also hard for experts because commercialized analytical program of photovoltaic systems is too complicated to use and domestic meteorological data is limited to partial areas. Therefore, we need evaluation program of BIPV system which can easily but accurately interpret generating performance and evaluate validity of BIPV system at the early stage of architectural design even for inexpert. Method: In this study, we collected meteorological data of domestic major region and analyzed generation characteristic of BIPV system by using PVsyst(commercialized software) in accordance with regions, types of solar module, place and methods of installation and so on. Based on this data, we developed performance evaluation program of BIPV system named BIPV-Pro, through multiple regression analysis and evaluated its validity. Result: When comparing predictive value of annual average PR and annual electricity production of BIPV-Pro an that of PVsyst, each of root mean square error was 0.01897 and 123.9.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.4
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• pp.11-21
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• 1988

In twentieth century, a rigid pavement composed of a series of thin Portland Cement Concrete has been accepted due to the desirable structural strength of concrete, durability and economy. However, despite of precise design and construction of concrete highway pavements, some of concrete pavements (example : Interstate-l0 and 75 in U.S.A, 88 Olympic express highway and Jung-bu express highway in Korea) has already shown severe signs of longitudinal and transverse cracking, faulting, and pumping before the end of their intended service life. This highlights the need for better understanding of concrete pavement behavior using structural analysis program. For these reasons, this research was performed to study an analytical behavior of concrete pavements, especially for the effects of skewed joints on concrete pavements. Subsequently, this research should give better understanding of concrete pavement behavior to the highway engineers and provide effective remedies to the concrete highway pavements.

• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.527-536
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• 2007

In this study, we applied 10-metric health assessment model, based on the Index of Biological Integrity (IBI) during 2006 in the Changwon Stream, which is located in the Changwon city, Gyeongnam province, S. Korea, and then compared with water quality data. The Index of Biological Integrity (IBI) in the Changwon Stream varied from 18 to 38 in the watershed depending on the sampling location and averaged 30.3 (n=6) during the study. Analysis of tolerance guilds showed that the proportion of sensitive species was 13%, but tolerant and intermediate species were 34% and 53%, respectively. Qualitative Habitat Evaluation Index (QHEI) averaged 43.3 (range: 65-104, n=6) indicating non-supporting condition, based on the criteria of U.S. EPA (1993). Values of QHEI showed a typical longitudinal decreases from the headwater reach to the downstream location, except for Site 1 with a low QHEI value by artificial habitat by concrete construction. Minimum QHEI was found in Site 4 where fish diversity was minimal. Conductivity increased continuously along the gradients and especially showed abrupt increases in the downstream sites along with turbidity. Stream ecosystem health of IBI matched to the values of QHEI except for S6. Low IBI values in the sites 4 and 5 was considered to be a result of combined effects of chemical pollutions and habitat degradations. Our results support the hypotheses of Plafkin et ai. (1989) that physical habitat quality directly influences the trophic structure and species richness, and is closely associated with IBI values.

• Structural Engineering and Mechanics
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• v.44 no.1
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• pp.51-60
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• 2012

Concrete sleepers are essential components of the conventional railway. As support elements, sleepers are always subjective to a variety of time-dependent loads attributable to the train operations, either wheel or rail abnormalities. It has been observed that the sleepers may deteriorate due to these loads, inducing the formation of hairline cracks. There are two areas along the sleepers that are more prone to crack: the central and the rail seat sections. Several non-destructive methods have been developed to identify failures in structures. Health monitoring techniques are based on vibration responses measurements, which help engineers to identify the vibration-based damage or remotely monitor the sleeper health. In the present paper, the dynamic effects of the cracks in the vibration signatures of the railway pre-stressed concrete sleepers are investigated. The experimental modal analysis has been used to evaluate the modal bending changes in the vibration characteristics of the sleepers, differentiating between the central and the rail seat locations of the cracks. Modal parameters changes of the 'healthy' and cracked sleepers have been highlighted in terms of natural frequencies and modal damping. The paper concludes with a discussion of the most suitable failure indicator and it defines the vibration signatures of intact, central cracked and rail seat cracked sleepers.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.108-115
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• 1990

This paper describes the design and fabrication of a processing element that will be used as a component in the construction of a two dimensional systolic for FFT. The chip performs data shuffling and radix-2 decimation-in-time (DIT) butterfly arithmetic. It consists of a data routing unit, internal control logic and HBA unit which computes butterfly arithmetic. The 6.5K transistors processing element designed with standard cells has been fabricated with a 2u'm double metal CMOS process, and evaluated by wafer probing measurements. The measured characteristics show that a HBA can be computed in 0.5 usec with a 20MHz clok, and it is estimated that the FFT of length 1024 can be transformed in 11.2 usec.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.383-390
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• 2011

In this study, a process combined biofiltration with sulfur-utilizing autotrophic denitrification and membrane separation was proposed to examine the efficiency of nitrogen removal. As an experimental device, hollow-fiber module was installed in the center of reactor to generate the flux forward sulfur layer in the cylinder packed with granular sulfur. In addition, a simple module was installed in activated sludge aeration tank which inside and outside of sulfur-using denitrification module was covered with microfilter and the module was considered as an alternative of clarifier. The experiment for developing new MBR process was carried out for three years totally. As the results of first two-year experiment, successful nitrogen removal performance was revealed with lab-scale test and pliot scale plant using artificial wastewater and actual plating wastewater. In this year, pilot scale test using actual domestic wastewater was performed to prove field applicability. As the results, high-rate nitrogen removal performance was confirmed with about 0.19 kg ${NO_3}^--N/m^3$ day of rate. Also significant fouling and pressure increase were not found during the experiment. And, the production ratio of sulfate and the consumption ratio of alkalinity showed a slightly higher value about 311 mg ${SO_4}^{2-}/L$ and 369 mg $CaCO_3$/L, respectively. In conclusion, the developed MBR process can be utilized as an alternative for retrofiting existing wastewater plants as well as new construction of advanced sewage wastewater treatment plants, with cost-effective merit.

• Journal of architectural history
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• v.19 no.4
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• pp.71-90
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• 2010

The names of Seokgatab and Dabotab are almost generalized among the people along with Bulguksa the most well-known temple in Korea. But, despite this generalized situation, the names of Seokgatab and Dabotab have not secured the clear standpoint till now. It is because the names of Seokgatab and Dabotab can be found only in the 18C documents like and . More complicatedly, in the record of the Goryeo sarira case found during the dismantling of Seokgatab, the name of Seokgatab was 'Mugujeonggwangtab' or 'Seoseoktab'. This paper is to secure the nominal validity of Seokgatab and Dabotab to remove the confusion due to their names and to raise the efficiency of studies related with Bulguksa in the future. First, their names and the problems related with them were summarized in Chapter 2. Based on this critical consciousness, Chapter 3 deals with the tragedy of Asadal related with the creation of the stone pagodas and its symbolic re-interpretation. In this process, we can see that there could be a viewpoint of the great comprehension in them through the completion of 'the Buddhist Nation'. Then, the architectural features of Seokgatab and Dabotab were analyzed in the ritual view point of . Finally, in Chapter 4, on the basis that the viewpoint of one specific sect can not be predominantly applied in the construction of Buddhist land, it is held that Avatamsaka Idea and Saddharma-pundarika Idea can coexist without any conflict. It is shown in the fact that Seokgatab and Dabotab can make harmony together in the Avatamsaka Idea while keeping their names. With these efforts, we can clearly see that the peculiar titles of Seokgatab and Dabotab can be said to secure sufficient validity.

• Journal of Arbitration Studies
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• v.8 no.1
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• pp.35-54
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• 1998

In recent years, there has been a significant increase in the number of large-scale projects involving construction, public works and the installation of industrial plants. These projects usually require the participation of a number of public and private entities and involve more than one contract. When disputes arising in connection with these projects are to be submitted to commercial arbitration, the parties often wish to have all disputes decided by one arbitral tribunal, in a single comprehensive proceeding. It has become apparent that the resolution of all major disputes which may arise in connection with such a project in a single comprehensive arbitration proceeding presents a number of advantages. The arbitral institution can provide for a multiparty arbitration proceeding only where all of the parties have agreed to it either at the time the disputes arise or at the time the parties enter into their various contractual arrangement. The discussion about multiparty arbitration centers on the question whether courts should have the power to order the consolidation of arbitration proceedings absent the consent of the parties. As the U.S. Supreme Court has repeatedly denied certiorari to cases presenting the consolidation-question, the conflict between the Court of Appeals' positions remains. The common method of selection in a bilaterial proceeding is the formula by which each party appoints one arbitrator and the two party-chosen arbitrators then mutually agree on a third, neutral arbitrator. This popular method poses, however, both a policy and practical problems In a 3-party-proceeding. It seems that the better solution is to have courts or arbitral institutions appoint all arbitrators for a multiparty proceeding. American courts have employed a variety of methods to appoint arbitrators for multiparty disputes in cases in which the parties had not provided for or could not agree upon a method themselves.

• Journal of Ecology and Environment
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• v.38 no.2
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• pp.133-143
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• 2015

Freshwater macrophytes improve the structural heterogeneity of microhabitats in water, often providing an important habitat for zooplankton. Some studies have focused on the overall influence of macrophytes on zooplankton, but the effects of macrophyte in relation to different habitat characteristics of zooplankton (e.g., epiphytic and pelagic) have not been intensively studied. We hypothesized that different habitat structures (i.e., macrophyte habitat) would strongly affect zooplankton distribution. We investigated zooplankton density and diversity, macrophyte characteristics (dry weight and species number), and environmental parameters in 40 shallow wetlands in South Korea. Patterns in the data were analyzed using a self-organizing map (SOM), which extracts information through competitive and adaptive properties. A total of 20 variables (11 environmental parameters and 9 zooplankton groups) were patterned onto the SOM. Based on a U-matrix, 3 clusters were identified from the model. Zooplankton assemblages were positively related to macrophyte characteristics (i.e., dry weight and species number). In particular, epiphytic species (i.e., epiphytic rotifers and cladocerans) exhibited a clear relationship with macrophyte characteristics, while large biomass and greater numbers of macrophyte species supported high zooplankton assemblages. Consequently, habitat heterogeneity in the macrophyte bed was recognized as an important factor to determine zooplankton distribution, particularly in epiphytic species. The results indicate that macrophytes are critical for heterogeneity in lentic freshwater ecosystems, and the inclusion of diverse plant species in wetland construction or restoration schemes is expected to generate ecologically healthy food webs.