• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.48-53
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• 1993

At present, the manufacturing industry is in a process of a great change. There is a demand for a variety of types and shorter product life. The change increases the number of different tools and frequencies of tool changes. For the most part, the tools are presetted and offset values are entered manually or via punched tapes to NC machines. Thus a large amount of capital is tied up in the tool area and considerable productive time is lost. Consequently, there is a need for improvement in tool management. This paper describes a computer controlled tool data management system which include: 1) tool identification with bar code. 2) computer aided management and updating of tool data. 3) tool data communication with tool presetter, CNC, etc.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1737-1738
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• 2008

In this paper, the performance of DSSS O-QPSK architecture for IEEE 802.15.4b LR-WPAN (Low-Rate Wire less Personal Area Network) is analyzed. Since the frequency offset of $\pm$40ppm on 868/915MHz band is recommended in IEEE 802.15.4b LR-WPAN specification. it is required to have a non-coherent detection that is stable operation in the channel environment with large frequency offset is required.

• Journal of Korean Institute of Industrial Engineers
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• v.3 no.1
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• pp.49-53
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• 1977

The coordinated control of the traffic signals of adjacent intersections can reduce delays, relative number of stops and congestions in the coordinated traffic area. The road capacity can be increased to a certain extend because the stopping and starting of vehicles facing red traffic lights can be avoided in many instances due to the progression established along an artery. However, if traffic centers or leaves the main flow in irregular volumes on the intermediate road section, a coordination of traffic signals is unnecessary and may even be harmful. Therefore, a computer simulation model to simulate and predict the effectiveness of a synchronized traffic signal system in the CBD of Seoul was developed and alternative policy variables, such as cycle time, offsets, phase splits, to be fed into the simulation model had to be generated. This is a report of (1) the development of a heuristic algorithm for the determination of phase splits when there are amber periods specifically reserved for left turns and (2) the computerization of time-space diagramming.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.2
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• pp.391-396
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• 2013

In this paper, for HEVC decoding, an SAO hardware design with less processing time and reduced area is proposed. The proposed SAO hardware architecture introduces the design processing $8{\times}8$ CU to reduce the hardware area and uses internal registers to support $64{\times}64$ CU processing. Instead of previous top-down block partitioning, it uses bottom-up block partitioning to minimize the amount of calculation and processing time. As a result of synthesizing the proposed architecture with TSMC $0.18{\mu}m$ library, the gate area is 30.7k and the maximum frequency is 250MHz. The proposed SAO hardware architecture can process the decode of a macroblock in 64 cycles.

• Journal of the Korean Graphic Arts Communication Society
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• v.25 no.1
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• pp.43-52
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• 2007

Offset printing is one of the well known printing technique of lithographic process and consists of image area and 'non-image area on a flat image carrier. The surface tension of dampening water can be controlled by adding IPA after mixing of raw water and etching solution. The etching solution contains a surfactant for reducing surface energy, a clean agent for non-imaging area, wetting agent for protecting non-imaging area from oil components like ink and also an emulsifying agent for controlling emulsification. In this study, the present situation of dampening water maintenance has examined by collecting dampening water using at domestic companies. The pH related to dampening water, conductivity, contact angle, emulsification curve are measured to define the current situation of dampening water control of each companies and to analyze the relationship among measured properties. In the study most of companies among 16 printing companies tested controlling dampening water through pH value. However, the quality of printing has varied depending upon conductivity, contact angle, IPA content, and emulsification value. The control of dampening water should be carry at the state of the standard when adding proper ratio of etching solution. It would be more effective when pH or conductivity control carries out in parallel with controlling dampening water. Therefore the concept that pH5.5 is correct is based concept. Based on these initial tests it is defined that the standardization of dampening water control is required.

• Korean Journal of Remote Sensing
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• v.38 no.2
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• pp.189-198
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• 2022

In this present study, we investigated the effect of the offset correction factor calculation method on the sulfur dioxide (SO₂) column density in the SO₂ retrieval algorithm of the Geostationary Environment Monitoring Spectrometer (GEMS) launched in February 2020. The GEMS operational SO₂ retrieval algorithm is the Differential Optical Absorption Spectroscopy (DOAS) - Principal Component Analysis (PCA) Hybrid algorithm. In the GEMS Hybrid algorithm, the offset correction process is essential to correct the absorption effect of ozone appearing in the SO₂ slant column density (SCD) obtained after spectral fitting using DOAS. Since the SO₂ column density may depend on the conditions for calculating the offset correction factor, it is necessary to apply an appropriate offset correction value. In this present study, the offset correction values were calculated for days with many cloud pixels and few cloud pixels, respectively. And a comparison of the SO₂ column density retrieved by applying each offset correction factor to the GEMS operational SO₂ retrieval algorithm was performed. When the offset correction value was calculated using radiance data of GEMS on a day with many cloud pixels was used, the standard deviation of the SO₂ column density around India and the Korean Peninsula, which are the edges of the GEMS observation area, was 1.27 DU, and 0.58 DU, respectively. And around Hong Kong, where there were many cloud pixels, the SO₂ standard deviation was 0.77 DU. On the other hand, when the offset correction value calculated using the GEMS data on the day with few cloud pixels was used, the standard deviation of the SO₂ column density slightly decreased around India (0.72 DU), Korean Peninsula (0.38 DU), and Hong Kong (0.44 DU). We found that the SO₂ retrieval was relatively stable compared to the SO₂ retrieval case using the offset correction value on the day with many cloud pixels. Accordingly, to minimize the uncertainty of the GEMS SO₂ retrieval algorithm and to obtain a stable retrieval, it is necessary to calculate the offset correction factor under appropriate conditions.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.16 no.1
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• pp.5-9
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• 2005

Background and Objectives : Glottal area waveform(GAW) shows the plot of glottal area versus time through the 1 cycle. This study is designed to see how it can be applied to laryngeal patients. Material and Methods : A GAW analysis was peformed on 11 patients before and after surgery and 22 persons without laryngeal problems were recruited for control. Acoustic and aerodynamic analysis with VHI(voice handicap index) evaluation were performed. Results. Significant changes in baseline offset, gross closing rate and VHI were observed postoperatively. Other parameters were changed but insignificant. Conclusion : GAW maybe used to evaluate patient with voice problems.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.60-67
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• 2008

A low-power 2.4GHz fractional-N frequency synthesizer has been designed for 2.4GHz ISM band applications such as Bluetooth, Zigbee, and WLAN. To achieve low-power characteristic, the design has been focused on the power optimization of power-hungry blocks such as VCO, prescaler, and ${\Sigma}-{\Delta}$ modulator. An NP-core type VCO is adopted to optimize both phase noise and power consumption. Dynamic D-F/Fs with no static DC current are employed in designing the low-power prescaler circuit. The ${\Sigma}-{\Delta}$ modulator is designed using a modulus mapping circuit for reducing hardware complexity and power consumption. The designed frequency synthesizer which was fabricated using a $0.18{\mu}m$ CMOS process consumes 7.9mA from a single 1.8V supply voltage. The experimental results show that a phase noise of -118dBc/Hz at 1MHz offset, the reference spur of -70dBc at 25MHz offset, and the channel switching time of $15{\mu}s$ over 25MHz transition have been achieved. The designed chip occupies an area of $1.16mm^2$ including pads where the core area is only $0.64mm^2$.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.5
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• pp.60-69
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• 2008

The principal reasons for applying a pigment coating to paper are to improve appearance and printability. The pigment coating provides a surface that is more uniform and more receptive to printing ink than are the uncoated fibers and, in turn, both facilitates the printing process and enhances the graphic reproduction. The improvement in print quality is readily apparent, especially in image areas or when multiple colors are involved. Although pigment coating of paper is to improve the printability, coated paper is not completely free from printing defects. Actually there are a number printing defects that are observed only with the coated papers. Among the printing defects that are commonly observed for coated papers, print mottle during multi-color offset printing is one of the most concerned defects, and it appears not only on solid tone area but also half dot print area. There are four main causes of print mottle ranging from printing inks, dampening solution, paper, and printing press or its operation. These indicates that almost every factors associated with lithographic printing can cause print mottle. Among these variation of paper quality influences most significantly on print mottle problems in multicolor offset printing, and this indicates that paper is most often to be blamed for its product deficiency as far as print mottle problems are concerned. Furthermore, most of the print mottle problems associated with paper is observed when coated papers are printed. Uncoated papers rarely show mottling problems. This indicates that print mottle is the most serious quality problems of coated paper products. Overcoming the print mottle is becoming more difficult because the operating speeds of coating and printing machines are increasing, coating weights are decreasing, and the demands on high-quality printing are increasing. Print mottle in offset printing is caused by (a) nonuniform back trap of ink caused by a nonuniform rate of ink drying, referred as "back trap mottle, and (b) nonuniform absorption of the dampening solution. Furthermore, both forms of print mottle have some relationship to the structure of the coated layer. The surest way of eliminating ink mottling is to eliminate unevenness in the base paper. Coating solutions, often easier to put into practice, should, however, be considered. In this paper the principal factors influencing print mottle of coated papers will be discussed. Especially the importance of base paper roughness, binder migration, even consolidation of coating layers, control of the drying rate, types of binders, etc. will be described.

• Korean Journal of Organic Agriculture
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• v.15 no.3
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• pp.291-307
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• 2007

The objective of this article is to examine the structure of the composition of the population in rural area for the last 45 years, and to forecast mid and long term structure of the population in the near future. Moreover, forecast has been done whether the rapid increase by the inflow of foreigners has any offset on the structural change in rural population. According to the research result, the rural area is experiencing a rapid decrease in population, a rapid increase in the percentage of the aged, and foreigners. To resolve the problematic situation mentioned above, some effective counterplan has to be considered by all agencies concerned.