• Journal of the Korea Institute of Building Construction
• /
• v.10 no.6
• /
• pp.19-26
• /
• 2010

Advanced construction technologies have been rarely applied to practical construction operations on jobsites due to a lack of quantified evaluation data of the performance of such technologies. The basic objective of this study is to suggest a feasible way for the evaluation of the performance of new technologies based on construction simulation techniques, which have been frequently used in academic research for productivity estimation. Steel staircase systems were selected as the new technology to be investigated. The simulation was implemented in various ways, such as one staircase to six staircases on a floor. The simulation results provided in this study suggest that planners are able to make a fundamental decision on the use of targeted new technology with the estimated performance data (productivity and unit costs). These findings also indicate that a simulation technique could be one of the methods appropriate for use as a planner's decision-making tool.

• Journal of Sensor Science and Technology
• /
• v.10 no.1
• /
• pp.33-41
• /
• 2001

Wire ropes have been widely used in industrial applications, wherever heavy weight should be carried safely or mechanical energy should be transmitted fast. Especially, wire rope failures in operating elevator may lead to extensive property damage and serious injury to nearby personnel. Hence, it is very important to inspect wire rope periodically. Failure defection of wire rope requires fundamental knowledge of wire rope construction, rope behavior, properties of fault, sensing and signal processing method. In this research, the development of a new fault detecting system incorporating Hall-effect sensors to detect flaws such as abrasion, broken wire, corrosion and deformation for aged wire ropes in elevator, is described. For using a detector as a portable instrument, several performances for implementing sensing part with Hall-effect sensor, analog signal processing unit and programs are described. Experiments and field testing results for the implemented detecting system are also given. As a result, it is verified that the detecting system has good efficiency for inspecting faults of aged wire ropes in service.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.23 no.4
• /
• pp.77-84
• /
• 2017

Purpose: In terms of the flexibility in hospital architecture, there are fixed elements of hospital architecture: mechanical, electrical, aeration rooms and shafts, which are the main utility spaces. Thus, it is necessary to recognize the utility space as a system that helps internal functions and flexible internal changes. This study analyzes the notion of the main utility space in hospital architecture and the architectural planning features of the main utility spaces as the system in the design process of the recently built hospitals. Methods: The design factors are extracted comparing two hospitals' plans in each stage and the systematic characteristics of utility spaces are analyzed accordingly. The opinions gathered from interviews of practitioners, architects and facility planning experts directly involved in the architecture design process are analyzed and reflected in the results. Results: Planning for utility spaces should be accompanied by the architectural plan from the basic design process, and proceeded with recognizing utility spaces as a system, which is a fixed element. Utility spaces are highly organically connected. Horizontal and vertical distribution of air chambers can reduce the length and number of ducts, and thus save story height, and reduce the number of shafts, the vertical connection passage. This is advantageous in securing the variable area, which is the ultimate objective of the system-centered hospital architecture plan. Implications: Thereby aims to provide fundamental data on systematic utility space planning in the hospital architecture planning.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.973-977
• /
• 2003

Land is the only immovable property that can be used, as a means for agricultural production as well as a means for mortgage for financing industrial or commercial enterprises. Spatial technologies play a key role in managing our land, water and natural resources. Cadastral data is a major component for the development of Land Information System. Therefore, systematic land registration system based on accurate and scientific cadastral map are found inevitable for poverty alleviation, good governance and women empowerment through security of their rights on property, as well as the planning and development of a sustainable environmental protection within Metropolitan city. Digital cadastral parcel is the fundamental spatial unit on which database is designed, created, maintained and operated. Availability of accurate and updated cadastral maps is a primary requisite for successful planning, policy formulating and maintenance of city utility services, which need cadastral and utility information together. Flawed cadastral maps can put land, revenue and taxation system at stake. Kathmandu the capital city of Nepal still is lacking utility maps combining cadastral information with the utility. There is an urgent need to have an effective, accurate and easy to access land revenue and utility services system within the urban areas which could be achieved after the production of reliable base maps and land registration system to guarantee land allocation and property rights which can well be achieved by digital conversion and correction of base cadastral maps. This paper highlights the drawbacks of the conventional cadastral maps and the possible advantages of digital cadastral maps over these. Also the problems, issues and implications during digital conversion and creating database of the same will be discussed.

• Korean Journal of Optics and Photonics
• /
• v.1 no.2
• /
• pp.210-216
• /
• 1990

This study was performed to obtain fundamental data on temperature increases in the dental tissues irradiated by IO.opm laser radiation. For this purpose a experimental facility was established. which was composed of a CO2 laser. a shutter unit and a temperature sensing device. The temperature changes in the pulp chamber of extracted molars. during and after the laser irradiation. were measured as function of laser power. the time of irradration and the thickness of the sample. An empirical formula for the maximum temperature increases, $\DeltaT_m$ was derived from the measured data as follows; $\DeltaT_m=\alphaP\Delta\tauexp(-\betad)$$ where P. $\Delta\tau$ and d are the laser power(W). irradiation time{sec) and the thickness(mm) between pulp chamber and occlusal surface. respectively. Also a theoretical calculation model based on simplified assumptions were established and the results from the calculation were compared with the measured temperature data. A fairly good agreement was obtained.obtained.

• Journal of KIISE:Computing Practices and Letters
• /
• v.5 no.6
• /
• pp.700-707
• /
• 1999

본 논문에서는 GIS 관련 연산을 실시간에 효율적으로 처리하기 위한 분산공유메모리 기반 병렬처리 시스템을 제안한다. 본 논문의 분산공유메모리 시스템은 메시지전달 방식의 분산메모리 MIMD 컴퓨터 상에 소프트웨어 기반 분산공유메모리 모듈을 탑재함으로써 구현되었다. 또한 GIS 연산의 기본이 되는 공간 객체를 공유의 기본 단위로 설정하고, GIS 데이타의 특성을 반영하여 읽기전용 공유데이타 타입을 추가하였으며, 네트워크 오버헤드를 줄이기 위하여 복수의 객체를 한번에 읽어오는 bulk access가 가능하도록 하였다. 본 시스템에서는 GIS 데이타의 효율적인 분배를 위하여 부하균등화 기법으로 guided self scheduling을 사용하였다. 실험결과 본 시스템은 네트워크 캐쉬의 효율적인 활용을 통하여 소프트웨어 기반 분산메모리 시스템의 오버헤드에도 불구하고 MPI 기반 메시지전달 방식에 비하여 향상된 성능을 얻을 수 있었다.Abstract In this paper, we propose a distributed shared memory(DSM) based parallel processing system to process GIS related computations efficiently in real time. The system is based on a software DSM module implemented on top of a distributed MIMD computer. In the DSM system, spatial object, which is a fundamental structure to represent GIS data, is used as a basic unit for sharing, and a read-only shared data type is added to reflect the characteristics of GIS data. In addition, a bulk access to multiple shared data is made possible to reduce the network overhead. A guided self scheduling method is devised for efficient load balancing in distributing GIS data to parallel processors. The experimental results show that the DSM system performs better than an MPI based message-passing system through the efficient utilization of network cache in spite of the system's software overhead.

• Coupled systems mechanics
• /
• v.2 no.3
• /
• pp.231-253
• /
• 2013

The impact of spar-nacelle-blade coupling on edgewise dynamic responses of spar-type floating wind turbines (S-FOWT) is investigated in this paper. Currently, this coupling is not considered explicitly by researchers. First of all, a coupled model of edgewise vibration of the S-FOWT considering the aerodynamic properties of the blade, variable mass and stiffness per unit length, gravity, the interactions among the blades, nacelle, spar and mooring system, the hydrodynamic effects, the restoring moment and the buoyancy force is proposed. The aerodynamic loads are combined of a steady wind (including the wind shear) and turbulence. Each blade is modeled as a cantilever beam vibrating in its fundamental mode. The mooring cables are modeled using an extended quasi-static method. The hydrodynamic effects calculated by using Morison's equation and strip theory consist of added mass, fluid inertia and viscous drag forces. The random sea state is simulated by superimposing a number of linear regular waves. The model shows that the vibration of the blades, nacelle, tower, and spar are coupled in all degrees of freedom and in all inertial, dissipative and elastic components. An uncoupled model of the S-FOWT is then formulated in which the blades and the nacelle are not coupled with the spar vibration. A 5MW S-FOWT is analyzed by using the two proposed models. In the no-wave sea, the coupling is found to contribute to spar responses only. When the wave loading is considered, the coupling is significant for the responses of both the nacelle and the spar.

• Journal of Climate Change Research
• /
• v.9 no.4
• /
• pp.453-460
• /
• 2018

The purpose of this study is to analyze the potential quantity of Korean Offset Credits (KOC) resulting from Certified Emission Reductions (CER) in 98 domestic Clean Development Mechanism (CDM) projects that were registered with the United Nations Framework Convention on Climate Change (UNFCCC) as of the end of 2016. Our results show that the total amount of potential KOC is 62,774 kt CO2eq. The potential KOC is only 23.4% of the total CER Issuance. During the first phase, this will be 3.2% of the allocated volume. This is because many projects are related to Renewable Portfolio Standard (RPS), HFC-23, and adipic acid N2O. There is a strong bias in some sectors and projects which could act as market distortion factors. Therefore, it is necessary to expand the target CDM project and activate non CDM offset projects. RPS projects bring fundamental changes to the energy sector, and it is worth reconsidering their acceptability. A wide variety of policy incentives are needed to address strong biases toward certain sectors and projects. The offset scheme has the advantage of allowing entities to reduce their GHG emissions cost effectively through a market mechanism as well as enabling more entities to participate in GHG reduction efforts both directly and indirectly. In contrast, having an inadequate offset scheme range and size might decrease the effort on GHG reduction or concentrate available resources on specific projects. As such, it is of paramount importance to design and operate the offset scheme in such a way that it reflects the situation of the country.

• International Area Studies Review
• /
• v.16 no.3
• /
• pp.77-97
• /
• 2012

Estimated coefficients has serious problems including inconsistency, biasness, etc. because many researches about the effect of fiscal decentralization on a country's economic growth use the traditional OLS method. Researches use the data intactly so that so called "spurious regression" phenomenon exists. This causes fundamental fallacy. This research tries unit root test, cointegration test, and then estimates the United States' economic time series by using VECM. The analysis of the effect of the state level-fiscal decentralization on economic growth shows two long term-equilibriums. During short term-dynamic adjustment, fiscal decentralization and economic growth move the same or different directions. In case of prediction GDP increases steeply and then from 2015 gently; and fiscal decentralization index shows a general reduction trend and then decreases slowly. At local level it shows two long term-equilibriums. During short term-dynamic adjustment, fiscal decentralization and economic growth also move the same or different directions. Impulse response analysis shows the very negative effect of fiscal decentralization on economic growth.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.5
• /
• pp.621-626
• /
• 2019

The driver's steering wheel maneuver is a typical disturbance that causes excessive body motion and traveling instability of a vehicle. Abrupt and extreme operation can cause rollover depending on the geometric and dynamic characteristics, e.g., SUV vehicles. In this study, to cope with the performance limitation of conventional cars, fundamental research on the structurization of a control system was performed as follows. Mathematical modeling of the lateral behavior induced by driver input was carried out. A controller was designed to reduce the body motion based on this model. An algorithm was applied to secure robust control performance against modeling errors due to parameter uncertainty, $H_{\infty}$. Using the decoupled 1/4 car, a dynamic load simulating model considering the body moment was suggested. The simulation result showed the validity of the load-simulating model. The framework for a lateral behavior control system is proposed, including an experimental 1/4 vehicle unit, load simulating module, suspension control module, and hardware-in-the-loop simulation technology.