• Title/Summary/Keyword: Noise Floor

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A Study on Stigma Effect of Unwelcomed Facilities on Apartment Prices: A Case Study of Sang-gye Jugong Apartment Complexes in Nowon-gu, Seoul (도시 비선호시설이 주변 아파트 가격에 미치는 낙인효과에 관한 연구 - 서울 노원구 상계동 주공 7, 9, 10단지를 사례로 -)

  • Kim, Chul-Joong;Song, Myung-Gyu
    • Journal of Environmental Impact Assessment
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    • v.21 no.2
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    • pp.297-314
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    • 2012
  • This study investigates the stigma effect of unwelcomed facilities on apartment prices through multiple regressions based on hedonic price method. The areas studied are Sang-gye Jugong 7, 9, 10 apartment complexes. The facilities analyzed are the Chang-dong Electric Subway Depot and the Do-bong Driver's License Agency. The factors studied include the environmental variable (the elapsed time since the announcement of the re-location of these facilities), the view commanding, the distance from Chang-dong Depot, the distance from Do-bong Driver's License Test Course, the distance from neighboring facilities (subway stations, schools, parks and so on), the floor and each dwelling's exclusive space. The data used are 2,822 sales which have been collected since January 1, 2006. The facts found are as follows; first, the view commanding and the distance from the unwelcomed facilities are statistically significant. second, the environmental variable, 'days' turns out to have a positive (+) and a negative (-) significant relationship with the dependent variable, 'price', in period II and period IV respectively. This implies that the stigma effect is real. third, there are significant differences in the influence on the apartment prices among the independent variables according to time. fourth, the stigma effect is estimated as 33,686,920 Korean won in the case of the apartments which have the view commanding and 30,311,844 won in the other case before the global economic crisis. This effect seems to decrease to 22,085,078 won after the crisis. These facts suggest that stigma effects could be considered as one of the benefits in the cost-benefit analysis of Chang-dong Depot re-location project to produce somewhat higher NPV or B/C ratio.

Crime Prevention by Using CPTED and Improvement (환경설계를 통한 범죄예방 및 개선방안)

  • Park, Kwang-Hyun
    • Journal of Digital Contents Society
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    • v.18 no.4
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    • pp.733-738
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    • 2017
  • This study is to find out empirically how the fear of crime is affected by the level of recognition of people. CPTED elements including natural surveillance, access control, utilization enhancement, territoriality securement, etc. Safety of residents could be considered and then increased when we plan, design, and operate a city. In Korea, CPTED is currently being applied to every town. However, it is not systemized and neither efficient, for there are no constraint provisions, and the foreign cases are not specifically customized to the current situation of the country. This study, therefore, aims to find the limits from analyzing related laws and regimes, administrative regulations, and applied cases, and to deduct improvement plans based on examined foreign cases.

A Study on the User Needs for Renovation of Race Track Type of Nursing Units in K University Hospital (K대학병원 병동부 이중복도형의 개선을 위한 사용자 요구 조사연구)

  • Kim, Youngaee;Yim, Ohyon;Kim, Jungshin;Yi, Jongse;Ahn, Uijong
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.19 no.3
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    • pp.21-28
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    • 2013
  • Purpose: General hospital in korea is getting large-scaled, specialized and upgraded. So, nursing unit of race track type has been advanced along with a spatial organization, building equipment and environmental approach. This study is to search the guidelines for renovation of nursing unit with race track type in the case of K university hospital in Daejeon. Methods: 9 cases of recently opened general hospital has been analyzed for spatial and environmental design solution. Questionnaires and interviews about user needs of nursing staff, patient and visitors, have been conducted for a nursing care system and facility of nursing units in K university hospital. Results: The user needs are represented as followings. Center core public zone in each floor plan and center core nursing station and supporting areas in nursing unit are good for an adjacency and separation of spatial organization. Toilet of group patient room is necessary to equip for easy, safe and infective aspects, and so toilet install will decrease the patient number and increase the nursing care service. Hall type of station front is good for visibility and observation. It is appropriate to renovate into south facing group patient room for privacy, enough space for nursing care facility and supporting area, enough width of door to move portable medical equipment, room for medical doctor and practical student, noise absorbing of day room. Implications: Upgrading the nursing care service and facility equipment is necessary to reflect the user needs and cooperate with hospital management.

Terra-Scope - a MEMS-based vertical seismic array

  • Glaser, Steven D.;Chen, Min;Oberheim, Thomas E.
    • Smart Structures and Systems
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    • v.2 no.2
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    • pp.115-126
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    • 2006
  • The Terra-Scope system is an affordable 4-D down-hole seismic monitoring system based on independent, microprocessor-controlled sensor Pods. The Pods are nominally 50 mm in diameter, and about 120 mm long. They are expected to cost approximately $6000 each. An internal 16-bit, extremely low power MCU controls all aspects of instrumentation, eight programmable gain amplifiers, and local signal storage. Each Pod measures 3-D acceleration, tilt, azimuth, temperature, and other parametric variables such as pore water pressure and pH. Each Pod communicates over a standard digital bus (RS-485) through a completely web-based GUI interface, and has a power consumption of less than 400 mW. Three-dimensional acceleration is measured by pure digital force-balance MEMS-based accelerometers. These accelerometers have a dynamic range of more than 115 dB and a frequency response from DC to 1000 Hz with a noise floor of less than $30ng_{rms}/{\surd}Hz$. Accelerations above 0.2 g are measured by a second set of MEMS-based accelerometers, giving a full 160 dB dynamic range. This paper describes the system design and the cooperative shared-time scheduler implemented for this project. Restraints accounted for include multiple data streams, integration of multiple free agents, interaction with the asynchronous world, and hardened time stamping of accelerometer data. The prototype of the device is currently undergoing evaluation. The first array will be installed in the spring of 2006.

The Effects of Hedonic Versus Utilitarian Attributes on the Consumer Acceptance of Intelligent Products (지능형제품의 쾌락적 속성과 실용적 속성이 소비자 수용도에 미치는 영향)

  • Kwak, Sonya S.
    • Design Convergence Study
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    • v.15 no.2
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    • pp.333-345
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    • 2016
  • Recently, an intelligent product in which information and robotic technologies are applied to an existing common product, called a mother product has been developed. In order to develop intelligent products which could be accepted by users, various intelligent product design methods have been introduced considering various interaction aspects or intelligent parts to be made. However, as an intelligent product is originated in a mother product, intelligent product design methods based on product attributes need to be explored. In this study, the impact of intelligent product types by product attributes on users' acceptance was investigated by comparing hedonic intelligent products and utilitarian intelligent products. An experiment was executed with child slippers as a case. As a result, participants evaluated utilitarian intelligent products more positively than hedonic intelligent products. They showed higher purchase intention and willingness to pay toward utilitarian intelligent products than hedonic intelligent products. In the case of child slippers, even though the hedonic attributes could be expected as they are child products, utilitarian attributes were perceived as much more important than hedonic attributes as the child slippers are related to the floor noise which is a severe social problem.

Structural damage identification with output-only measurements using modified Jaya algorithm and Tikhonov regularization method

  • Guangcai Zhang;Chunfeng Wan;Liyu Xie;Songtao Xue
    • Smart Structures and Systems
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    • v.31 no.3
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    • pp.229-245
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    • 2023
  • The absence of excitation measurements may pose a big challenge in the application of structural damage identification owing to the fact that substantial effort is needed to reconstruct or identify unknown input force. To address this issue, in this paper, an iterative strategy, a synergy of Tikhonov regularization method for force identification and modified Jaya algorithm (M-Jaya) for stiffness parameter identification, is developed for damage identification with partial output-only responses. On the one hand, the probabilistic clustering learning technique and nonlinear updating equation are introduced to improve the performance of standard Jaya algorithm. On the other hand, to deal with the difficulty of selection the appropriate regularization parameters in traditional Tikhonov regularization, an improved L-curve method based on B-spline interpolation function is presented. The applicability and effectiveness of the iterative strategy for simultaneous identification of structural damages and unknown input excitation is validated by numerical simulation on a 21-bar truss structure subjected to ambient excitation under noise free and contaminated measurements cases, as well as a series of experimental tests on a five-floor steel frame structure excited by sinusoidal force. The results from these numerical and experimental studies demonstrate that the proposed identification strategy can accurately and effectively identify damage locations and extents without the requirement of force measurements. The proposed M-Jaya algorithm provides more satisfactory performance than genetic algorithm, Gaussian bare-bones artificial bee colony and Jaya algorithm.

Characteristics of Random Jitter in Analog Fiber-Optic Links Employing a Mach-Zehnder Modulator and an EDFA (마하-젠더 광 변조기와 EDFA를 사용한 아날로그 광통신 링크의 랜덤 지터 특성)

  • Yoon, Young-Min;Lee, Min-Young;Shin, Jong-Dug;Kim, Boo-Gyoun
    • Journal of IKEEE
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    • v.13 no.4
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    • pp.96-102
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    • 2009
  • We investigate the characteristics of RJ (random jitter) in an analog fiber-optic link employing a MZM (Mach-Zehnder modulator) and an EDFA (Erbium-doped fiber amplifier). RJ has been measured using two methods, one of which derived from the noise spectrum of a RF spectrum analyzer and the other from the histogram data of a sampling oscilloscope. If the optical power and/or the RF power input to the MZM increase, RJ decreases due to the output signal power increase. For the optical link without EDFA, the minimum RJ is about 1 ps at an RF power of 10 dBm and an optical power of 8 dBm measured using the noise spectrum method. For the optical link with an EDFA, RJ decreases toward a jitter floor as the EDFA gain increases. If the gain increases further, it has been observed that RJ increases from the minimum. If the EDFA gain is fixed, RJ is smaller for the case of larger optical input power. As the EDFA gain increases, RJ reduction rate becomes greater for the case of lower optical input power.

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Utilization of Charcoal as an Environmentally Friendly Building Materials (II) - A Study on the Energy Saving and Sound Insulation Characteristics of Building Materials Prepared with Charcoal - (목탄을 이용한 친환경 건축자재 이용기술(II) - 목탄 함유 건축자재의 에너지 절감 및 차음 특성에 관한 연구)

  • Ahn, Byoung-Jun;Paik, Ki-Hyon
    • Journal of the Korean Wood Science and Technology
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    • v.39 no.1
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    • pp.41-52
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    • 2011
  • This study was carried out to investigate the effect of energy saving and sound insulation of building materials mixed with charcoal. To investigate the functionality of building based on the difference of construction materials, three different experimental buildings were constructed. They were buildings built with the conventional construction materials (A), the charcoal construction materials (B), and the charcoal-sericite construction materials (C). The study showed that energy consumption could be reduced approximately 9.5% and 14.5% by replacing A with B and C, respectively. Especially, it is revealed that the lower outdoor temperature was, the higher energy saving effect was. Also, after shutoff the boiler switch the decrease rate of room temperature of the one using B was lower than those of others using A and C so that the room temperature at the building using B was higher by $3.5{\sim}4.2^{\circ}C$ in the 1 meter air above the ground and by $4.4{\sim}5.4^{\circ}C$ on the floor surface after 12 hours passed. In the building noise test the heavy-and light-weight impact sound of the plate, represented by criterion of noise between floors in multi-story building, tended to decrease in the test sample containing charcoal.

Semi-Automatic Method for Constructing 2D and 3D Indoor GIS Maps based on Point Clouds from Terrestrial LiDAR (지상 라이다의 점군 데이터를 이용한 2차원 및 3차원 실내 GIS 도면 반자동 구축 기법 개발)

  • Hong, Sung Chul;Jung, Jae Hoon;Kim, Sang Min;Hong, Seung Hwan;Heo, Joon
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.2
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    • pp.99-105
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    • 2013
  • In rapidly developing urban areas that include high-rise, large, and complex buildings, indoor and outdoor maps in GIS become a basis for utilizing and sharing information pertaining to various aspects of the real world. Although an indoor mapping has gained much attentions, research efforts are mostly in 2D and 3D modeling of terrain and buildings. Therefore, to facilitate fast and accurate construction of indoor GIS, this paper proposes a semi-automatic method consisting of preprocessing, 2D mapping, and 3D mapping stages. The preprocessing is designed to estimate heights of building interiors and to identify noise data from point clouds. In the 2D mapping, a floor map is extracted with a tracing grid and a refinement method. In the 3D mapping, a 3D wireframe model is created with heights from the preprocessing stage. 3D mesh data converted from noise data is combined with the 3D wireframe model for detail modeling. The proposed method was applied to point clouds depicting a hallway in a building. Experiment results indicate that the proposed method can be utilized to construct 2D and 3D maps for indoor GIS.

A Geographically Weighted Regression on the Effect of Regulation of Space Use on the Residential Land Price - Evidence from Jangyu New Town - (공간사용 규제가 택지가격에 미치는 영향에 대한 공간가중회귀분석 - 장유 신도시지역을 대상으로-)

  • Kang, Sun-Duk;Park, Sae-Woon;Jeong, Tae-Yun
    • Management & Information Systems Review
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    • v.37 no.3
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    • pp.27-47
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    • 2018
  • In this study, we examine how land use zoning affects the land price controlling other variables such as road-facing condition of the land, land form, land age after its development and land size. We employ geographically weighted regression analysis which reflects spatial dependency as methodology with a data sample of land transaction price data of Jangyu, a new town, in Korea. The results of our empirical analysis show that the respective coefficients of traditional regression and geographically weighted regression are not significantly different. However, after calculating Moran's Index with residuals of both OLS and GWR models, we find that Moran's Index of GWR decreases around 26% compared to that of OLS model, thus improving the problem of spatial autoregression of residuals considerably. Unlike our expectation, though, in both traditional regression and geographically weighted regression where residential exclusive area is used as a reference variable, the dummy variable of the residential land for both housing and shops shows a negative sign. This may be because the residential land for both housing and shops is usually located in the level area while the residential exclusive area is located at the foot of a mountain or on a gentle hill where the residents can have good quality air and scenery. Although the utility of the residential land for both housing and shops is higher than its counterpart's since it has higher floor area ratio, amenity which can be explained as high quality of air and scenery in this study seems to have higher impact in purchase of land for housing. On the other hand, land for neighbourhood living facility seems to be valued higher than any other land zonings used in this research since it has much higher floor area ratio than the two land zonings above and can have a building with up to 5 stories constructed on it. With regard to road-facing condition, land buyers seem to prefer land which faces a medium-width road as expected. Land facing a wide-width road may have some disadvantage in that it can be exposed to noise and exhaust gas from cars and that entrance may not be easy due to the high speed traffic of the road. In contrast, land facing a narrow road can be free of noise or fume from cars and have privacy protected while it has some inconvenience in that entrance may be blocked by cars parked in both sides of the narrow road. Finally, land age variable shows a negative sign, which means that the price of land declines over time. This may be because decline of the land price of Jangyu was bigger than that of other regions in Gimhae where Jangyu, a new town, also belong, during the global financial crisis of 2008.