• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.1 s.113
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• pp.27-33
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• 2006

Newsprint is quantitatively the most important printing paper. The demands for its printability are continuously increasing. It is well known that the relationship between the physically tested paper properties and newspaper printability is unsatisfactory. In order to improve the printing quality of Korean newsprint, the printability coefficients such as maximum ink requirement(Ymax), print through were investigated. Kinds of newspapers and black printing ink were tested by IGT printability tester. Experiment condition of IGT printability tester was 14 steps between $0.2{\sim}2.8g/m^2$ of ink requirement, printing pressure was 200 N and printing velocity was 1 m/sec. The properties of newspaper samples (basis weight, bulk density, roughness, smoothness, porosity, i. e.) were examined in accordance with KS and TAPPI standard testing methods. The result of this study are respected for usefulness printing quality management of Korean newsprint.

• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.141-152
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• 2004

In this paper, we propose the index structure supporting the future position retrievals with efficiently updating continuous positions of moving objects in location based services. For reducing update costs of moving objects, our index structure directly accesses to the leaf node with moving objects using secondary index structure and performs bottom up update when node information is changed. Positions of moving objects are stored in primary index structure. In primary index structure, the split information similar to kd-tree is stored to internal node for increasing node's fanout. And the proposed index structure supports the future position retrievals using velocity of moving objects in the child node.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7B
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• pp.583-594
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• 2006

WPANs (Wireless personal area networks) have developed as various forms according to requirements such as data rate, coverage, subscriber volume, and supported mobile velocity. And mobile device with multiple network interfaces is very common. To make these multi-mode devices communicate with any WPAN device at anytime, anywhere, the framework for heterogeneous wireless networks is essential. Therefore, we propose the integration framework to converge heterogeneous WPANs. In this paper, we explain the requirements and detailed design of our framework, and then present the emulation test results.

• Journal of Information Processing Systems
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• v.6 no.3
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• pp.347-358
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• 2010

This paper presents a measurement system for 3D hand-drawn gesture motion. Many pen-type input devices with Inertial Measurement Units (IMU) have been developed to estimate 3D hand-drawn gesture using the measured acceleration and/or the angular velocity of the device. The crucial procedure in developing these devices is to measure and to analyze their motion or trajectory. In order to verify the trajectory estimated by an IMU-based input device, it is necessary to compare the estimated trajectory to the real trajectory. For measuring the real trajectory of the pen-type device, a PHANToMTM haptic device is utilized because it allows us to measure the 3D motion of the object in real-time. Even though the PHANToMTM measures the position of the hand gesture well, poor initialization may produce a large amount of error. Therefore, this paper proposes a calibration method which can minimize measurement errors.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.10 s.352
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• pp.55-59
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• 2006

In cellular OFDMA(Orthogonal Frequency Division Multiple Access) systems, each subcarrier may suffer from different amount of interferences from neighbor cells. Suppose that it is possible to accurately estimate inter-cell interferences for each subcarrier, the performance can be considerably improved by applying SINR(Signal to Interference and Noise Ratio) weighting. This paper proposes an inter-cell interference estimation method for cellular OFDMA systems. The proposed method extracts amounts of noise and interferencesby eliminating the channel variation effects of pilot symbols caused by frequency offset, timing offset mobile velocity, and delay spread.

• Journal of Environmental Science International
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• v.18 no.9
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• pp.941-952
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• 2009

The urban microscale wind field around the air quality monitoring station was investigated in order to check how a building complex influences it. For this study as the high density areas Jwa-dong and Yeonsan-dong monitoring sites in Busan were chosen. As the direction of inflow which is perpendicular to the building of the monitoring station was expected to cause the considerable variation of the wind field, that direction was selected. The model Envi-met was used as the diagnostic numerical model for this study. It is suitable for this investigation because Envi-met has the microscale resolution. After simulating it, on the leeward side around a building complex the decrease of flow velocity and some of vortexes or circulation area were discovered. In addition, on the edge of the top at the building and at the back of the building the upward flow was developed. If the sampling hole of monitoring site were located in this upward flow, it would be under the influence of upward flow from the near street.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.27-33
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• 2004

In this paper, we present a carrier recovery circuit using the polarity-decision algorithm that recovers a phase and a frequency error simultaneously. The proposed algorithm catches a frequency error based on a differential of an angular velocity of the signal constellations. Using the differential of a phase error may compensate the frequency error. The symbol prediction method in the proposed algorithm accumulates the symbols, which makes easy to calculate a phase differential. The hardware size of the algerian is small since we use Q data or I only to get phase information. As a result, the algerian shows a pull-in range of normalized frequency error 0.5 under AWGN 15dB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1718-1726
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• 2006

In this paper, we proposed a fuzzy controller and algorithm for efficiently obstacle avoidance in unknown space. The ultrasonic sensor is used for position and distance recognition of obstacle, and fuzzy controller is used for left and right wheels angular velocity control. The fuzzification is used singleton method and the control rule is each wheel forty-nine. The fuzzy inference is used simplified Mamdani's reasoning and defuzzification is used SCOG(Simplified Center Of Gravity). The computer simulation based on mobile robot modelling was performed for the capacity of fuzzy controller and the really applicable possibility revaluation of the proposed avoidance algorithm and fuzzy controller. As a result, mobile robot was exactly reached in target and it avoided obstacle efficiently.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.386-391
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• 2000

Due to its characteristics of acoustic wave energy absorption, punched structures are generally applied on the wall of anechoic room. When the acoustic wave propagates through the punched plates, its energy dissipates into thermal energy by flow separation induced from the viscosity of acoustic media. The acoustic pressure difference between the for-side and the aft-side of punched plate ran be represented by the sum of drag term proportional to square of velocity and inertia term proportional to acceleration. The way to get the coefficients of the terms by an experiment or relatively simple calculation is introduced.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2B
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• pp.160-169
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• 2002

While radar operator recognizes and tracks threat targets through the scope, it is essential to overcome the jamming signal that disturbs the normal operation of the radar. Therefore, to train operator and test the EW capability of the radar, this paper proposed the jamming signal simulation algorithm and design results to generate the deception jamming(range, velocity, angle deception and multiple false targets) and noise jamming signals(spot, barrage, swept spot and cover pulse noise). And also, the radar jamming signal simulator composed of the 6 constituents is developed on basis of the proposed algorithm and digital circuit design technique and confirmed the validity of the developed simulator by means of the test results to generate the various jamming signal.