• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.04a
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• pp.94-99
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• 1994

최근 인구의 과밀화와 이에 따른 지가의 상승 등으로 대표적인 주거용 빌딩인 아파트의 고층화가 급속하게 진행되고 있고 아파트에 설치되는 엘리베이터도 점차 대형화, 고속화 되고 있다. 실례로 15층 아파트의 경우 11인승, 60m/min의 엘리베이터가 일반적으로 사용되는 반면, 20층 아파트의 경우 17인승, 90m/min이 주로 사용된다. 이와 같이 엘리베이터의 용량과 운행 속도가 증가함에 따라 필연적으로 소음 및 진동 문제가 발생하게 된다. 특히 아파트의 경우 침실, 공부방 등 고도의 정숙을 요하는 생활 공간이 많고, 내부 공간의 활용도를 높이기 위하여 이들 방들이 엘리베이터 기계실 또는 운행 통로와 직접 접하여 있는 경우도 있어 이 경우 소음, 진동 문제는 아주 심각한 문제로 대두된다. 본 연구소가 측정한 방에 의하면 S신도시 L아파트의 경우 아파트 최상층 방에서 실내 소음도가 46dB(A), 벽의 진동가속도가 3.4mm/s$^{2}$(RMS)으로 나타났다. 진동의 경우 생활에 직접적인 악영향을 미칠 수준은 아니지만 소음의 경우 ASHRAE 권장 주택소음 기준치가 35dB(A) 이하임ㅇㄹ 감안하면 주거에 곤란한 수준이다. 수년전, 고층 아파트가 보급될 초기에는 아파트에 엘리베이터가 설치되어있다는 그 자체만으로 충분한 장점이 되어 다소음 소음, 진동문제는 큰 불만거리가 되지 않았지만 엘리베이터가 보편화된 지금에는 엘리베이터의 편리성만으로는 점점더 크게 요구되는 정숙성이 보상되지 않는다. 따라서 전반적인 아파트의 소음, 진동 문제에 큰 비중을 차지하는 엘리베이터에 의한 소음, 진동에 관하여 체계적인 연구가 필요하다. 이에 본고에서는 엘리베이터에 의한 아파트의 소음 및 진동에 관하여 그 현황, 원인 그리고 대책에 관한여 논하고자 한다.감 방법을 연구하였고, T.Sakai는 5자유도 모델을 이용하여 엔진 공회전시 발생하는 치타음에 대해 이론과 실험을 통해 해석하고, 엔진 회전수 변동, 클러치 특성, 변속기의 드래그(drag) 토크의 영향과 치타음 저감을 위한 개선된 클러치 특성을 제시하였다. 이 외에도 Thomas C.T.와 E.P.Petkus는 특정 차량에 대한 동력전달계의 비틀림 진동 현상에 대해 연구하였다. 이러한 연구들로 볼 때, 자동차 동력전달계에서 발생하는 진동은 이론과 실험을 통해 그 해석이 가능하며 설계에 매우 유용하게 이용되고 있음을 알 수 있다. 따라서, 본 연구는 4 실린더 4 싸이클 1.5 L 엔진을 장착한 경승용차의 실차 주행실험을 통해 가속 페달의 급조작에 따른 차체의 종진동 현상을 측정하고, 엔진-변속기-타이어-차체의 반환정계 4자유도 진동모델로 시뮬레이션을 수행하여 실차 주행실험의 결과치와 비교, 분석한 후 클러치 비틀림 특성을 비롯한 자동차 동력전달계의 각 설계인자들이 차체의 종진동에 어떠한 영향을 미치는가를 해석하고자 한다.be presented.LIFO, 우선 순위 방식등을 선택할 수 있도록 확장하였다. SIMPLE는 자료구조 및 프로그램이 공개되어 있으므로 프로그래머가 원하는 기능을 쉽게 추가할 수 있는 장점도 있다. 아울러 SMPLE에서 새로이 추가된 자료구조와 함수 및 설비제어 방식등을 활용하여 실제 중형급 시스템에 대한 시뮬레이션 구현과 시스템 분석의 예를 보인다._3$", chain segment, with the activation energy of carriers from the shallow trap with 0.4[eV], in he amorphous regions.의 증발산율은 우기의 기상자료를 이용하여 구한 결과 0.05 - 0.1

• Journal of IKEEE
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• v.25 no.2
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• pp.267-272
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• 2021

Recently, attention has been focused on renewable energy and carbon neutrality to resolve fossil energy depletion and environmental problems. In addition, high-rise urban buildings and an increase in building energy are rapidly increasing. There are many restrictions on installing solar power in urban areas. In addition, as buildings become taller, a lot of low-light environments in which shade is formed occur. Therefore, in this study, we intend to develop a power plant capable of generating electric power in an outdoor low-light environment and indoor lighting environment. The power plant in a low-light environment used a dye-sensitized solar cell. A unit cell and a 20cm×20cm module were manufactured, and the electrical characteristics of the power plant were measured using light sources of LED, halogen lamp, and 3-wavelength lamp. The photoelectric conversion efficiency of the unit cell was 17.2%, 1.28%, 19,2% for each LED, halogen lamp, and 3-wavelength lamp, and the photoelectric conversion efficiency of the 20cm×20cm module was 10.9%, 8.7%, and 11.8%, respectively. In addition, the maximum power value of the module was 13.1mW, 15.7 mW, and 14.2 mW for each light source, respectively, confirming the possibility of power generation in a low-light environment

• Atmosphere
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• v.20 no.4
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• pp.467-482
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• 2010

In this study, characteristics of various stability indexes (SI) and environmental parameters (EP) for the lightning are analysed by using 5 upper air observatories (Osan, Gwangju, Jeju, Pohang, and Baengnyeongdo) for the years 2002-2006 over South Korea. The analysed SI and EP are the lifted index, K-index, Showalter stability index, total precipitable water, mixing ratio, wind shear and temperature of lifting condensation level. The lightning data occurred on the range of -2 hr~+1 hr and within 100 km based on the launch time of rawinsonde and observing location are selected. In general, summer averaged temperature and mixing ratio of lower troposphere for the lightning cases are higher about 1 K and $1{\sim}2gkg^{-1}$ than no lightning cases, respectively. The Box-Whisker plot shows that the range of various SI and EP values for lightning and no lightning cases are well separated but overlapping of SI and EP values between lightning and no lightning are not a little. The optimized threshold values for the detection of lightning are determined objectively based on the highest Heidke skill socre (HSS), which is the most favorable validation parameter for the rare event, such as lightning, by using the simulation of SI and EP threshold values. Although the HSS is not high (0.15~0.30) and the number and values of selected SI and EP are dependent on geographic location, the new threshold values can be used as a supplementary tool for the detection or forecast of lightning over South Korea.

• Korean Journal of Construction Engineering and Management
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• v.11 no.2
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• pp.137-146
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• 2010

Becoming construction projects larger and more complicated, and utilizing more varied and complex contracting and delivery systems in the industry, integrating information and managing constructability from project inception to completion became the most critical tasks for the successful project management. However, current industry practices of constructability analysis which are too much dependent on field engineers and managers' experiences, are not performed efficiently and also not managed effectively. Then the scope, method, and procedure in performing analysis tasks are not certain as well as not systematic, In addition, due to using 2D based drawings and documents, information required at project phases for the analysis is inconsistent and inaccurate. This study aims to suggest the use of BIM technology and functions for solving various problems of current constructability practices. In particular, constructability analysis tasks performed at design and construction stages are identified and their adaptability, applicability, and benefits of BIM are investigated through interviews on constructability and BIM professionals in the industry.

• Fire Science and Engineering
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• v.21 no.4
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• pp.105-114
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• 2007

Recently the consideration for occupants' security has been raised as very important design element from the fire by building's large sized, higher storied, and its compounded. But the domestic Laws regulated the predicative laws according to the technical standard which has no difference from the past domestic evacuation regulations. Therefore when big fire occurs, it is not enough to guarantee for occupants to escape safely. Specially since domestic escape relevant laws are divided into Architect relevant law and fire fighting relevant law, it has caused to bring various problems. So This study will show the problems of the evacuation regulation which is registrated in the Architect relevant law and fire fighting relevant law. And also later, when Architect escape relevant laws re-registrate, this study will be used as foundational materials.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.22-29
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• 2015

Modern structures is the tendency of being increasingly taller and larger. The concrete with large weight has the disadvantage of increasing the weight on the structure. therefore, the method of carrying out the weight saving of the concrete is required. one of such method is to use a lightweight aggregate. However, studies on structural lightweight concrete, lacking for the recognition of the lightweight concrete, so also is lacking. therefore it is necessary to study on the physical characteristic value of the lightweight concrete. In this study, in order to investigate the tensile properties of lightweight concrete, Crack mouth opening displacement (CMOD) experiments were carried out. the fracture energy of the lightweight concrete subjected to inverse analysis were derived from the CMOD experimental results.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.453-463
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• 2017

Due to the increase in the size of buildings and scale, the importance of construction engineering that reflects the constructability from the design stage of the project is increasing. Especially, engineering efforts related to facilities, equipment and construction methods for temporary work at the design stage can significantly contribute to improvement of constructability and project performance. The purpose of this study is to derive construction engineering tasks on temporary work at the design phase of the high-rise building projects. 27 preliminary tasks were firstly investigated through literature review and experts' group interview, and the necessity and importance analysis of each tasks were then performed based on questionnaire survey. Most of the tasks related to plans on structural framework and lifting equipment were analyzed as relatively more important ones. Lastly, 21 engineering tasks, which are classified into 5 factors, were proposed through factor analysis. The factors were determined as 1) structural framework, measurement and circulation, 2) lifting equipment and pumping, 3) space zoning, 4) water supply, 5) temporary facility, electric power supply and lighting. The results of this study can be used as basic data for establishing efficient work process of construction engineering on temporary work at the design phase.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.108-116
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• 2008

At present, construction automation is a critical solution for the shortage of labor and the aging of skilled workers. Especially, researches for transportation automation are achieved to improve the efficiency as the construction of tall-building construction. Transportation automation needs to control the swung member by the inertia and/or the wind-force at the end of cable. However, previous to control, the presupposition of the swing is heavily difficult work because the inertia and the wind force are irregularly changable according to work condition. Therefore, in this study, dynamic modeling of crane and simulation was performed to find the characteristic of the swing. In the result, the maximum displacement of the swung material was analyzed. And, on the basis of analysis, the criteria to decide workability of automated transportation considering the material size and the wind force onsite was proposed.

• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.173-181
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• 2003

During the last few years, the use of Pre-tensioned spun high strength concrete piles(PHC pile) has been gradually increased in many construction sites. Cutting work of the concrete pile is an important task to crush a part of pile head which is compressed with more than 800$\cal{kg}f/cm^2$. It is usually performed by a crusher and three to four skilled workers. Recent analysis results of the pile cutting work reveal that it frequently makes a lot of cracks which significantly reduce the strength of the pile and is labor-intensive work. The primary objective of this study is to propose conceptual designs for developing an automated pile cutting machine. It is anticipated that the development of the automated pile cutting machine would be able to bring improvements in safety, productivity, quality as well as cost saving.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.305-310
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• 2008

A lot of changes are required in a management method of a project because the character of construction projects gets bigger and higher gradually. Especially, for the efficiency of the management method the plans of various viewpoints focused on the construction supply chain field that the technical application of Ubiquitous Technologies such as RFID/USN is being advanced actively are presented. Recently, the introduction of the intelligent equipment which is developed for intelligence of construction site requires the new process model in the construction supply chain management on the construction site. Therefore, this study is to propose the intelligent construction supply chain reference model development in order to provide the guide that the numerous materials for construction could easily be applied in the changed process, as mentioned above, by overcoming the limit of the existing construction supply chain process which is proposed as bar codes and RFID/USN based individual material types and reflecting the change factors like the intelligent equipment of construction supply chain management.