• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.879-891
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• 2018

In this study, the effects of urban redevelopment and building construction on the change of the detailed flows around the Pukyong National University (PKNU) campus located in the building-congested area was investigated using a CFD (computational fluid dynamics) model and GIS (geographic information system). For the analysis of the detailed flows before and after the constructions of the buildings around and within the campus, numerical simulations for the 16 inflow directions were performed before and after the construction. We used, as reference wind speeds at the inflow boundaries, the averaged wind speeds observed at the Gwangan light beacon (962) where there is no surrounding obstacle (i.e., building and terrain) acting as friction. We analyzed the area fractions in which wind speeds at z = 2.5 m changed after the construction for 16 inflow directions. The area fractions were relatively large in the east-south-easterly and southerly cases, because of the high-rise buildings constructed at the east and the apartment complex and the Engineering buildings constructed at the south of the PKNU campus. In the case of the easterly of which frequency is highest among the wind directions observed at the Daeyeon AWS (AWS 942) located inside the PKNU campus, the wind-speed change was not significant even after the constructions. It is shown that the building construction has affected the detailed flows around as well as even in the far downwind region of the constructed buildings. Also, it is shown that the GIS and CFD model are useful for analyzing the detailed flows in planning the urban redevelopment and/or building construction.

• Convergence Security Journal
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• v.17 no.5
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• pp.143-151
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• 2017

The purpose of this study is to provide the future development of the PRC Marine Corps by analyzing the changing functions via its historical development. The PRCMC is an elite regular military forces and was established by the Central Military Commission(China) in 1953 in order to project the national military power toward the enemy's territory by overcoming maritime obstacles such as seas and lakes. The PRCMC is relatively smaller personnel strength compared with the whole size of the PRC military forces. Thus its functions were limited in the areas of amphibious and land operations, island and land defense against Taiwan before the PRC pursues expanding policy toward outside. However, in the 2000s, China pursues its policy for obtaining absolute national interest so that its functions are rapidly enlarged into defense of the forward naval bases, and those for evolving its power toward outside according to not only the island territorial dispute with Japan, but also Xi Jinping's active expanding policy what we call 'the one belt and one road'. So its personnel strength is slowly increased. If the increasement of the PRC Navy and Marine Corps would develop into the level of which they can contain the status and influence of the US military power in Asia-Pacific area, it is possible that the security environment of the North-east Asia including the Korean peninsula will be fluctuated. Consequently, the ROK also needs to reevaluate the functions and the size of the joint strength of the ROK Navy and Marine Corps considering the transition of the changing security environment.

• Journal of the Korea Society for Simulation
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• v.30 no.2
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• pp.1-9
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• 2021

Many factors such as wind direction, wind strength, temperature, and obstacles affect a munition's trajectory. Since these factors eventually determines the probability of hit and the hitting point of a target, these factors should be considered to obtain reliable weapon effectiveness data. In this study, we propose the extension of the MSDL(Military Scenario Definition Language) to reflect these factors to improve the reliability of weapon effectiveness data. Based on the existing MSDL, which has been used to set the initial condition of a military simulation scenarios, the newly identified subelements are added in ScenarioID, Environment, Organizations, and Installations as a scenario schema. Also, DamageAssessment and DesignOfExperiments element are added to make weapon effectiveness data easily. The extended MSDL enables to automatically generate the simulation scenarios that reflect various factors which affect the probability of hit or kill. This extended MSDL is applied to an integrated simulation software of weapon systems, named AddSIM version 4.0 for generation of weapon effectiveness data.

• Journal of Broadcast Engineering
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• v.28 no.2
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• pp.213-229
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• 2023

In this paper, we introduce a spatial sound rendering system that provides 6DoF spatial sound in real time in response to the movement of a listener located in a virtual environment. This system was implemented using MPEG-I AEP as a development environment for the CfP response of MPEG-I Immersive Audio and consists of an encoder and a renderer including a decoder. The encoder serves to offline encode metadata such as the spatial audio parameters of the virtual space scene included in EIF and the directivity information of the sound source provided in the SOFA file and deliver them to the bitstream. The renderer receives the transmitted bitstream and performs 6DoF spatial sound rendering in real time according to the position of the listener. The main spatial sound processing technologies applied to the rendering system include sound source effect and obstacle effect, and other ones for the system processing include Doppler effect, sound field effect and etc. The results of self-subjective evaluation of the developed system are introduced.

• Journal of Platform Technology
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• v.11 no.2
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• pp.26-38
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• 2023

This paper is a study on a transport robot capable of autonomously driving to a destination using a QR code in an indoor environment. The transport robot was designed and manufactured by attaching a lidar sensor so that the robot can maintain a certain distance during movement by detecting the distance between the camera for recognizing the QR code and the left and right walls. For the location information of the delivery robot, the QR code image was enlarged with Lanczos resampling interpolation, then binarized with Otsu Algorithm, and detection and analysis were performed using the Zbar library. The QR code recognition experiment was performed while changing the size of the QR code and the traveling speed of the transport robot while the camera position of the transport robot and the height of the QR code were fixed at 192cm. When the QR code size was 9cm × 9cm The recognition rate was 99.7% and almost 100% when the traveling speed of the transport robot was less than about 0.5m/s. Based on the QR code recognition rate, an experiment was conducted on the case where the destination is only going straight and the destination is going straight and turning in the absence of obstacles for autonomous driving to the destination. When the destination was only going straight, it was possible to reach the destination quickly because there was little need for position correction. However, when the destination included a turn, the time to arrive at the destination was relatively delayed due to the need for position correction. As a result of the experiment, it was found that the delivery robot arrived at the destination relatively accurately, although a slight positional error occurred while driving, and the applicability of the QR code-based destination self-driving delivery robot was confirmed.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.305-313
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• 2016

Movements of the lower limb are important for normal walking and smooth oscillation of the center of gravity. The ankle rotations such as dorsi-flexion, plantar-flexion, inversion and eversion allows the foot to accommodate to ground during level ground walking. Current below knee (B/K) prostheses are used for replacing amputated ankle, and make it possible for amputees to walk again. However, most of amputees with B/K prostheses often experience a loss of terrain adaptability as well as stability because of limited ankle rotation. This study is focused on the development of multi-rotational prosthetic foot for lower limb amputee. Our prosthesis is possible for amputees to easily walk in level ground by rotating ankle joint in sagittal plane and adapt to the abnormal terrain with ankle rotation in coronal plane. The resistance of ankle joint in the direction of dorsi/plantar-flexion can be manually regulated by hydraulic damper with controllable nozzle. Furthermore, double layered rubber induce the prosthesis adapt to irregular ground by tilting itself in direction of eversion and inversion. The experimental results highlights the potential that our prosthesis induce a normal gait for below knee amputee.

• Archives of design research
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• v.13 no.3
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• pp.211-220
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• 2000

Cultural contact, which means a current that an influential culture diffuses to another, represents the penetration of the one to the other in a negative respect and'mixture'or 'fusion'of them in an affirmative respect. Fusion of cultures was not easy to take place in the past when nationalism and ultranationalism suppressed it ideologically, inconvenient transportation and communications were obstacles to it, and most of countries were under the influences of folk religions. Today, however, mutually heterogeneous cultures can be shared by a lot of things such as collapse of a view of nation resulted from globalization, breakdown of regional characteristics, abolition of trade barriers, freedom of communications and realtime information network. Those have rendered fusion possible. Fusion in this modern consuming society is extending much faster and more extensively than at any time in the past. In addition, more and more cultural elements seem to collide and compromise with one another in the name of fusion, not relaxing the bridle of fusion, from the present situations that preference in consumption becomes subdivided and a variety of individuality is strongly attempted to seek for, This study is on the subject of the properties of'Fusion', one of new styles in a mass culture, especially focused on sociologic cultural phenomena. Furthermore, it is expected to look for a fusion in interior design which expresses sociologic cultural phenomena most in a field of design, to examine it theoretically, and to prospect a future trend of fusion design based on investigation of the latest prevailing trend.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10C
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• pp.995-1006
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• 2003

It is well know that in the wireless communication systems the transmitted signals can suffer from multipath fading due to the wave propagation characteristics and the obstacles over the paths, resulting in serious reduction in the power of the received signals. However, it is possible to take advantage of the inherent diversity imposed in the multipath reception if the underlying channel can be properly estimated. One of the diversity reception methods in this case is Rake processing. In this paper we study the Rake receivers for the direct-sequence spread-spectrum communication systems utilizing PN (pseudo noise) sequences to achieve spread spectrum. A conventional Rake receiver can use the finite-duration impulse (FIR) filter followed by the PN sequence demodulator, where the FIR filter coefficients are the reverse-ordered complex conjugate values of the fading channel impulse response estimates. Here, we propose a new Rake processing method by replacing the aforementioned PN code sequence with a new set of optimum demodulator coefficients. More specifically, the concept of the new optimum Rake processing is first introduced and then the optimum demodulator coefficients are theoretically derived. The performance obtained using the new optimum Rake processing is also calculated. The analytical results are verified by computer simulation. As a result, it is shown that the new optimum Rake processing method improves the MSE performance more than 10 dB over the conventional one using the fixed PN sequence demodulator. It is also shown that the new optimum Rake processing method improves the MSE performance about 10 dB over the Adaptive Correlator that performs the combining of the multipath components and PN demodulation concurrently. And finally, the MSE performance of the optimum Rake demodulator is very close to the MSE performance of OPSK demodulator under the AWGN channel.

• Journal of Intelligence and Information Systems
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• v.20 no.3
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• pp.1-18
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• 2014

Over the past years RFID/SN has been an elementary technology in a diversity of applications for the ubiquitous environments, especially for Internet of Things. However, one of obstacles for widespread deployment of RFID technology is the inherent unreliability of the RFID data streams by tag readers. In particular, the problem of false readings such as lost readings and mistaken readings needs to be treated by RFID middleware systems because false readings ultimately degrade the quality of application services due to the dirty data delivered by middleware systems. As a result, for the higher quality of services, an RFID middleware system is responsible for intelligently dealing with false readings for the delivery of clean data to the applications in accordance with the tag reading environment. One of popular techniques used to compensate false readings is a sliding window filter. In a sliding window scheme, it is evident that determining optimal window size intelligently is a nontrivial important task in RFID middleware systems in order to reduce false readings, especially in mobile environments. In this paper, for the purpose of reducing false readings by intelligent window adaption, we propose a new adaptive RFID data cleaning scheme based on window sliding for a single tag. Unlike previous works based on a binomial sampling model, we introduce the weight averaging. Our insight starts from the need to differentiate the past readings and the current readings, since the more recent readings may indicate the more accurate tag transitions. Owing to weight averaging, our scheme is expected to dynamically adapt the window size in an efficient manner even for non-homogeneous reading patterns in mobile environments. In addition, we analyze reading patterns in the window and effects of decreased window so that a more accurate and efficient decision on window adaption can be made. With our scheme, we can expect to obtain the ultimate goal that RFID middleware systems can provide applications with more clean data so that they can ensure high quality of intended services.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1824-1832
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• 2011

In this paper, a smart home service robot McBot II is newly developed in much more practical and intelligent system than McBot I which we had developed a few years ago. Thus far, vacuum-cleaners have lightened the burden of household chores but the operational labor that vacuum-cleaners entail has been very severe. Recently, a cleaning robot was commercialized to solve but it also was not successful because it still had the problem of mess-cleanup, which pertained to the clean-up of large trash and the arrangement of newspapers, clothes, etc. Hence, we develop a new home mess-cleanup robot McBot II to completely overcome this problem on real environments. The mechanical design and the basic control of McBot II, which performs mess-cleanup function etc. in house, is actually focused in this paper. McBot II is mechanically modeled in the same method that the human works in door by using the waist and the hands. The big-ranged vertical lift and the shoulder joints to be able to forward move are mechanically designed for the operating function as the human's waist when the robot works. The mobility of McBot II is designed in the holonomic mobile robot for the collision avoidance of obstacle and the high speed navigation on the small area in door. Finally, good performance of McBot II, which has been optimally desinged, is confirmed through the experimental results for the control of the robotic body, mobility, arms and hands in this paper.