• Annual Conference of KIPS
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• 2002.11a
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• pp.543-546
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• 2002

최근들어 IT 산업이 급속도로 발전하면서, 리소스가 제한된 작은 기기들의 사용이 비약적으로 증가하는 추세에 있다. 이들 기기들에 플랫폼 독립성(Platform Independency), 보안성(Security), 이동성(Mobility) 등의 장점을 포함하고 있는 자바 환경을 적용하려는 연구가 계속되고 있는데, 자바 환경의 핵심인 자바가상머신(Java Virtual Machine: JVM) 임베디드 시스템이나 모바일 시스템과 같이 작고, 자원이 제한적인 장치에 탑재하기에 너무 큰 용량(footprint)을 차지한다. 이를 해결하기 위해 좀더 경량화한 가상머신이 필요하였다. 본 논문에서는 네트워크 연결 능력이 있고 적은 리소스를 가진 다양한 기기들에 적합한 최소 크기의 표준 자바 플랫폼에 대한 Configuration 인 CLDC(Connected, Limited Device Configuration)에서 정의하고 있는 K가상머신(K Virtual Machine: KVM)에 대해 분석하고 설계한 내용을 기술하고 있다.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.6-9
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• 2015

Traditional project management theory is based on a three-dimensional life cycle approach where the project managerseeks to optimize the dimensions of cost-schedule-technical (quality or design). This paper reports the findings of a case study analysis of two complex mega-projects in Michigan which confirm the findings of previous research and illustrates the use of a framework for five-dimensional project management (5DPM) that is for conceptualizing a complex project's scope of work. The framework elevates the recognition that the project's social/political context and the financial arrangements create complexity adding two new dimensions. This paper also demonstrates a methodology to graphically display a project's complexity to better understand and prioritize the available resources. The result is a "complexity footprint" that may help a complex project manager identify the boundary between controllable and uncontrollable projects impacts. The paper finds that applying 5DPM to the two case study projects has given the project delivery team a tool which is actually adding value to the complex project management process.

• Atmosphere
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• v.25 no.2
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• pp.193-203
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• 2015

A large aperture scintillometer (LAS) was deployed with an optical path length of 2.1 km to estimate turbulent sensible heat flux (${\mathcal{Q}}_H$) over a highly heterogeneous urban area. Scintillation measurements were conducted during cold season in November and December 2013, and the daytime data of 14 days were used in the analysis after quality control processes. The LAS-derived ${\mathcal{Q}}_H$ show reasonable temporal variation ranging $20{\sim}160W\;m^{-2}$ in unstable atmospheric conditions, and well compare with the measured net radiation. The LAS footprint analysis suggests that ${\mathcal{Q}}_H$ can be relatively high when the newly built-up urban area has high source contribution of the turbulent flux in the study area ('northwesterly winds'). Sensitivity tests show that the LAS-derived ${\mathcal{Q}}_H$ are highly sensitive to non-dimensional similarity function for temperature structure function parameter, but relatively less sensitive to surface aerodynamic parameters and meteorological variables (temperature and wind speed). A lower Bowen ratio also has a significant influence on the flux estimation. Overall uncertainty of the estimated daytime ${\mathcal{Q}}_H$ is expected within about 20% at an upper limit for the analysis data. It is also found that stable atmospheric conditions can be poorly determined when the scintillometry technique is applied over the highly heterogeneous urban area.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.151-162
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• 1998

During a straight driving and cornering maneuver by a vehicle various forces and moments are exerted on the tire's footprint. A cornering properties, handling and stability performances of vehicle can be predicted by these forces and moments values. Therefore, on this study, a lateral force and a aligning torque are predicted by these forces and moments values. Therefore, on this study, a lateral force and a aligning torque are predicted using a finite element method. Contact area of the tire between bead and wheel are fixed to simplify of a finite element model. Lateral force is exerted on the rigid surface as a real load with Coulum friction after inflate and load vertically. Then, rotate the tire's axle to simulate a free rolling untill taken the equilibrium of a aligning torque. Also, experimental observations are made to test a reliability of a FE analysis conducted in this study. The finite element analysis said that good agreement was obtained with experimental results of these cornering properties, giving confidence within about one percent. So it os recommended that a finite element analysis can be used as a good tool to predicted the tire cornering properties.

• Korean Journal of Remote Sensing
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• v.23 no.3
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• pp.211-219
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• 2007

Building extraction is one of the essential issues for 3D city modelling. In recent years, high-resolution satellite imagery has become widely available and it brings new methodology for urban mapping. In this paper, we have developed a semi-automatic algorithm to determine building heights from monoscopic high-resolution satellite data. The algorithm is based on the analysis of the projected shadow and actual shadow of a building. Once two roof comer points are measured manually, the algorithm detects (rectangular) roof boundary automatically. Then it estimates a building height automatically by projecting building shadow onto the image for a given building height, counting overlapping pixels between the projected shadow and actual shadow, and finding the height that maximizes the number of overlapping pixels. Once the height and roof boundary are available, the footprint and a 3D wireframe model of a building can be determined. The proposed algorithm is tested with IKONOS images over Deajeon city and the result is compared with the building height determined by stereo analysis. The accuracy of building height extraction is examined using standard error of estimate.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.4
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• pp.40-51
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• 2014

This study aims to investigate urban inundation considering building footprints based on dual-drainage scheme. For this purpose, LiDAR data is cultivated to generate two original data set in terms of DEM with $1{\times}1$ meter and building layer of the study drainage area in Seoul and then the building layer is overlapped as vector polygon with the mesh data with the same size as DEM. Then, terrain data for modeling were re-sampled to reduce resolution as $10{\times}10$ meters. As results, the simulated depth without considering building footprints has a tendency to underestimate the inundation depth compared to observed data analized by CCTV imagery. Otherwise, the simulation result considering building footprints revealed definitely higher fitness. The difference of inundation depth came from the variation of inundation volume which was relevant to inundation extent. If the building footprints are enlarged, the possible inundation depth is increased, which results in being inundation depth higher because hydrological conditions such as rainfall depth are conservational. Otherwise, according to comparison of inundation extents, there were no significant difference but the case of considering building footprint was revealed slightly higher fitness. Thus, it is concluded that the considering building footprint for inundation analysis of urban watershed should be required to improve simulation accuracy synthetically.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.4 s.316
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• pp.28-35
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• 2007

Airbone laser altimeters have been utilized for 3D topographic mapping of the earth, moon, and planets with high resolution and accuracy, which is a rapidly growing remote sensing technique that measures the round-trip time emitted laser pulse to determine the topography. The traveling time from the laser scanner to the Earth's surface and back is directly related to the distance of the sensor to the ground. When there are several objects within the travel path of the laser pulse, the reflected laser pluses are distorted by surface variation within the footprint, generating multiple echoes because each target transforms the emitted pulse. The shapes of the received waveforms also contain important information about surface roughness, slope and reflectivity. Waveform processing algorithms parameterize and model the return signal resulting from the interaction of the transmitted laser pulse with the surface. Each of the multiple targets within the footprint can be identified. Assuming each response is gaussian, returns are modeled as a mixture gaussian distribution. Then, the parameters of the model are estimated by LMS Method or EM algorithm However, each response actually shows the skewness in the right side with the slowly decaying tail. For the application to require more accurate analysis, the tail information is to be quantified by an approach to decompose the tail. One method to handle with this problem is proposed in this study.

• Journal of Fashion Business
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• v.3 no.2
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• pp.77-83
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• 1999

For the purpose of investigating the factor of foot and calf growth of primary-school children who are fastgrowing during this period, a group of the 1st graders of primary-school had been the subject of this measurement in 1995 and thereafter they became the subject again in 1997 when they were the 3rd graders. Measurement was carried out in 30 items including height and weight and marthin-type measurer and Footprint were used for this measurement. As the result, in the part of calf, the measuring items of maximum calf circumference and knee circumference, and in the part of foot, the items of instep circumference, heel circumference, instep circumference, measured angle of big toe showed the highest growth. The average growth of length for 2 years appeared about 2cm and the parts of instep circumference, heel circumference had rapidly grown rather than in the part of foot circumference. Height growth of the part of toe was about 0.1 and in the factor analysis of foot measurement of 8-year and 10-year and children, the following findings appeared in both cases that height was related with the items of calf height and foot length and weight was related with calf circumference and breadth, foot circumference items.

• Journal of information and communication convergence engineering
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• v.12 no.3
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• pp.186-192
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• 2014

Monolithic three-dimensional integrated chips (3D ICs) are an emerging technology that offers an integration density that is some orders of magnitude higher than the conventional through-silicon-via (TSV)-based 3D ICs. This is due to a sequential integration process that enables extremely small monolithic inter-tier vias (MIVs). For a monolithic 3D memory, we first explore the static random-access memory (SRAM) design. Next, for digital logic, we explore several design styles. The first is transistor-level, which is a design style unique to monolithic 3D ICs that are enabled by the ultra-high-density of MIVs. We also explore gate-level and block-level design styles, which are available for TSV-based 3D ICs. For each of these design styles, we present techniques to obtain the graphic database system (GDS) layouts, and perform a signoff-quality performance and power analysis. We also discuss various challenges facing monolithic 3D ICs, such as achieving 50% footprint reduction over two-dimensional (2D) ICs, routing congestion, power delivery network design, and thermal issues. Finally, we present design techniques to overcome these challenges.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.373-376
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• 2008

Wireless sensor networks consist of thousands of sensor nodes that have low power, low footprint and low computational capacities. So the burning issues in the design and deployment of these sensor nodes in the practical application areas include the energy conservation and network lifetime. Efficient routing schemes can help reduce the energy consumption and thus increase the network lifetime. This paper deals with the comparative analysis of popular routing protocols such as LEACH, LEACH-C, MTE, and PEGASIS. The protocols are compared by using performance me tries such as system lifetime, the time for first node death, and total system energy.