• Journal of Environmental Science International
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• v.16 no.4
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• pp.495-503
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• 2007

In this study, we took the geometrical character of the river channel junction and hydrologic conditions as independent variables, and hydraulic behavior characteristics as an independent variable. The result, after multiple analysis was carried out, proved that, except for the generating area of the accelerating zone of velocity the accelerating zone and both the main channel and the tributary zone of stagnation the stagnation zone, there was correlation of over 90%. Also, derived presumed expression of the hydraulic characteristics of the junction was applied to the real natural channel - the river channel of the Guem-ho main channel(the A-yang bridge to the Guem-ho bridge). As the result, it proved that it represented hydraulic characteristics relatively well.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.392-397
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• 1997

In this paper, design and analysis of anchorage zone in prestressed concrete structure using nonlinear strut and tie model is presented. Nonlinear strut and tie model is an analysis and design model which constructs strut and tie model based on nonlinear analysis considering the nonlinear behavior of concrete. Based on the nonlinear strut and tie model, the analysis and design are performed for the anchorage zone having singular concentric tendons, singular eccentric tendons and multiple tendons, respectively. For verification of the model, comparisons are made with experimental results as well as results by linear strut and tie models. from the comparisons, it is shown that the design of the anchorage zone by the nonlinear model is still economical without loosing the degree of safety and the prediction of the ultimate load by the nonlinear model gives better accuracy than by the linear one.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.126-132
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• 2006

In this paper, we aim to control the sound and vibration spatially, so that a desired physical variable is enhanced within a zone we select. This is somewhat analogous to have manipulators that can draw wave shape in any place we want. Brightness and contrast control have shown that such a manipulation is possible by controlling multiple sources[J.-W. Choi and Y.-H. Kim, J. Acoust. Soc. Am. 111(4), 2002]. In particular, the acoustic brightness control seeks a way to increase loudness of sound over a chosen area, and the contrast control aims to enhance loudness difference between two neighboring regions. This enables us to manipulate spatial distribution of sound by making two different kinds of zone ? the bright and dark zone- at the same time. The primary focus of this study is to unit the theoretical formulation of the brightness and contrast control and to find a link between these methods, as well as its relation to other conventional techniques. It is also shown that we can generate various shape of wave field by transforming the domain we consider.

• ETRI Journal
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• v.40 no.6
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• pp.736-744
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• 2018

This study considers zone-based registration (ZBR), which is adopted by most mobile cellular networks. In ZBR, a user equipment (UE) registers its location area (or zone) in a network database (DB) whenever it enters a new zone. Even though ZBR is implemented in most networks for a UE to keep only one zone (1ZR), it is also possible for a UE to keep multiple zones. Therefore, a ZBR with two zones (2ZR) is investigated, and some mathematical models for 2ZR are presented. With respect to ZBR with three zones (3ZR), several studies have been reported, but these employed computer simulations owing to the complexity of the cases, and there have been no reports on a mathematical 3ZR model to analyze its performance. In this study, we propose a new mathematical model for 3ZR for the first time, and analyze the performance of 3ZR using this model. The numerical results for various scenarios show that, as the UE frequently enters zones, the proposed 3ZR model outperforms 1ZR and 2ZR. Our results help determine the optimal number of zones that a UE keeps, and minimize the signaling cost for radio channels in mobile cellular networks.

• Journal of The Korean Astronomical Society
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• v.52 no.5
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• pp.173-180
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• 2019

We present IR flux density measurements, models of the broadband SED, and results of SED modeling for the Pulsar Wind Nebula (PWN) 3C 58. We find that the Herschel flux density seems to be slightly lower than suggested by interpolation of previous measurements in nearby wavebands, implying that there may be multiple electron populations in 3C 58. We model the SED using a simple stationary one-zone and a more realistic time-evolving multi-zone scenario. The latter includes variations of flow properties in the PWN (injected energy, magnetic field, and bulk speed), radiative energy losses, adiabatic expansion, and diffusion, similar to previous PWN models. From the modeling, we find that a PWN age of 2900-5400 yrs is preferred and that there may be excess emission at ${\sim}10^{11}Hz$. The latter may imply multiple populations of electrons in the PWN.

• Journal of Ocean Engineering and Technology
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• v.6 no.1
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• pp.96-104
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• 1992

Aircraft structures and engineering structures are always subject to variable amplitude loads. Variable amplitude loads include some kind of loading history; for example, constant amplitude load, single peak overload and block overload etc. Crack growth under variable amplitude loading exhibits retardation effect. In this study, the 4 point bending fatigue test was performed by hydrolic servo fatigue testing machine on 7075-T6 Al-alloy. The retardation effect of overload ratio and numbers of overload cycle was quantitatively studied. 1) Change of retardation effect against increment of overload ratio is more evident when the multiple overload is applied than single overload is done. 2) The number of overload cycle is very important factor about the crack growth retardation effect when the overload ratio is more than 1.75; that is not when the overload ratio is less than 1.75. 3) Overload affected zone size increased gradually by increment of crack growth retardation effect. 4) Crack driving force is more greatly reduced when the crack tip branched off two direction than it sloped to one direction.

• International Journal of High-Rise Buildings
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• v.8 no.1
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• pp.71-82
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• 2019

The purpose of this study is to evaluate the indoor air quality (IAQ) and energy benefits of a dedicated outdoor air system (DOAS) and compare them with a conventional variable air volume (VAV) system. The DOAS is a decoupled system that supplies only outdoor air, while reducing its consumption using an enthalpy wheel. The VAV system supplies air that is mixed outdoor and transferred indoor. The VAV has the issue of unbalanced ventilation in each room in multiple zones because it supplies mixing air. The DOAS does not have this problem because it supplies only outdoor air. That is, the DOAS is a 100% outdoor air system and the VAV is an air conditioning system. The transient simulations of carbon dioxide concentration and energy consumption were performed using a MATLAB program based on the thermal loads from the model predicted by the TRNSYS 18 program. The results indicated that when the air volume is large, such as in summer, the distribution of air is not appropriate in the VAV system. The DOAS however, supplies the outdoor air stably. Moreover, in terms of annual primary energy consumption, the DOAS consumed approximately 40% less energy than the VAV system.

• Journal of the Korean earth science society
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• v.26 no.5
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• pp.436-442
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• 2005

We have performed multiple geophysical surveys comprised of gravity, magnetic and resistivity methods at the Yangsan fault zone which runs through the Eonyang area, the eastern part of Kyeongsang in southeast Korea. The gravity and magnetic data provide information about geological structures. Furthermore, sections of electrical resistivity show the sharp contrast of electrical resistivity distribution across the fault zone. Since the fractured zone tends to be more conductive than fresh host rocks, the electrical resistivity survey is effective in determining the detailed structure of the fault zone. We have made gravity measurements at a total of 71 points alongside two profiles across the fault zone, and carried out an electrical resistivity survey with a dipole-dipole array at the same location using 40m dipole length. In addition, we have analyzed the aeromagnetic data on the corresponding area. The multiple geophysical properties appear to be abruptly changed in electrical resistivity, gravity and aeromagneticclearly show the different appearance across the fault zone. The fault is identified by its sub vertical attitude which is well known in the Yangsan fault zone. We have also confirmed that the magnitude of the response of the fault is much larger in the southern part of the survey area than the northern area. These results most likely to provide basic information for the further studies about the physical properties and the structures at the Yangsan fault.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3533-3538
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• 2015

Background: Multiple primary malignancies (MPM) have become increasingly prevalent worldwide. This investigation was aimed at establishing the clinicopathological characteristics of MPM patients and evaluating the impact of the living environment on MPM in the Taiwanese population. Materials and Methods: From January 2009 to December 2013, a total of 8,268 cancer patients were identified in our institutional center. Of these, 125 were diagnosed as MPM and thus enrolled. Data for clinicopathological features and treatment approaches for these MPM patients living in urban or suburb zone were obtained. Findings for the air pollution status in Taiwan were also collected. Results: The most common cancer match of MPM was esophageal cancer with hypopharyngeal cancer (12.8%), followed by colorectal cancer with gastric cancer (6.4%) and colorectal cancer with breast cancer (5.6%). The air quality was significantly worse in the urban than in the suburban zone and there was a remarkably higher portion of MPM patients in the urban zone suffering from grade III and IV post-chemotherapeutic neutropenia (30.8% vs 15.1%, P=0.036). Conclusions: The tumor frequency and site distribution should be taken into the clinical evaluation because there is a relatively high risk of developing MPM. This study also highlighted the potential influence of environmental factors on post-chemotherapeutic neutropenia for patients with MPM.

• Journal of the Korea Society of Computer and Information
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• v.18 no.11
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• pp.87-97
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• 2013

In the RFID system, multiple tags respond in the process of identifying multiple tags in the reader's interrogation zone, resulting in collisions. Tag collision occurs when two or more tags respond to one reader, so that the reader cannot identify any tags. These collisions make it hard for the reader to identify all tags within the interrogation zone and delays the identifying time. In some cases, the reader cannot identify any tags. The reader needs the anti-collision algorithm which can quickly identify all the tags in the interrogation zone. The proposed algorithm efficiently divides tag groups through an efficient separation to respond, preventing collisions. Moreover, the proposed algorithm identifies tags without checking all the bits in the tags. The prediction with efficient separation reduces the number of the requests from the reader.