• Journal of Adhesion and Interface
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• v.16 no.1
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• pp.29-34
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• 2015

Hydrocarbon resins, which are defined as low molecular weight, amorphous, and thermoplastic polymers, are widely used as tackifier for various types of adhesives, as processing aids in rubber compounds, and as modifiers for plastics polymers such as isotactic polypropylene. Typically, hydrocarbon resins are non-polar, and thus highly compatible with non-polar rubbers and polymer. However, they are poorly compatible with polar system, such as acrylic copolymer, polyurethanes, and polyamides. Moreover, recently the raw materials of hydrocarbon resin from naphtha cracking had been decreased because of light feed cracking such as gas cracking. To overcome this problem, in this study, novel hydrocarbon resins were designed to have a highly polar chemical structure which material is sustainable. And, it was successfully synthesized by Diels-Alder reaction of dicyclopentadiene monomer and sorbic acid from blueberry as renewable resources. Acrylic resins were formulated with various tackifiers solution including sorbic acid grafted hydrogenated dicyclopentadiene hydrocarbon resins in acrylic adhesive and rolling ball tack, loop tack, $180^{\circ}$ peel adhesion strength, and shear adhesion strength were measured. The properties depend on the softening point and polar content of tackifiers.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1140-1142
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• 2002

This paper is proposed to position and speed control of interior permanent magnet synchronous motor(IPMSM) drive without mechanical sensor. The rotor position, which is an essential component of any vector control schemes, is calculated through the instantaneous stator flux position and an estimated flux value of rotating reference frame. A closed-loop state observer is implemented to compute the speed feedback signal. The validity of the proposed sensorless scheme is confirmed by simulation and its dynamic performance is examined in detail.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.435-436
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• 2008

This paper presents a dual band frequency synthesizer for GSM and Wideband CDMA which is designed in a standard 0.13um CMOS 1P6M process. The shared components include phase frequency detector (PFD), charge pump (CP), loop filter, integer frequency divider(128/129 DMP, 4bit PC, 3bit SC) and Low noise Ring-VCO. A high-speed low power dual modulus prescaler is proposed to operate up to 2.1GHz at 3.3V supply voltage with 2mW power consumption by simulation. The simulated phase noise of VCO is -101dBc/Hz at 200kHz offset frequency from 1.9GHz.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.5 s.311
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• pp.62-71
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• 2006

Development of an artificial reverberation algorithm with low memory requirements has been an issue of importance in applications such as mobile multimedia devices. One possible solution to this problem is to embed a time-varying all-pass filter to the feedback loop of the comb filter. In this paper, theoretical and perceptual analyses of reverberators embedding time-varying all-pass filters are presented. The analyses are to iud a perceptually acceptable degree of phase variation by the all-pass filter. Based on the analyses, we propose a new methodology of designing reverberators embedding time-varying all-pass filters. Through the subjective tests, we showed that, even with smaller memory, the proposed method is capable of providing perceptually comparable sound quality to the conventional methods involving time-invariant parameters.

• Journal of the Korea Society for Simulation
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• v.27 no.1
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• pp.119-126
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• 2018

This study intended to exploratively testify human error causing factors for railway traffic controller, using AMOS structural equation model. Through literature survey, fatigue and stress as exogenous variable, errors in information process such as cognitive, memory, storage, and execution error as endogenous variable, and accident and incident(near-miss) as dependent variable were set up. Results based on AMOS using 201 railway traffic controllers' questionnaire showed that a clear causality loop like as 'stress ${\rightarrow}$ memory error ${\rightarrow}$ storage error ${\rightarrow}$ incident(near-miss) ${\rightarrow}$ accident' is formed. This result suggests that for the purpose of mitigation of traffic controller's accident, it is so necessary to reduce memory and execution error in the information processing process based on the effective management of stress, as the precedent of them.

• The Journal of Dong Guk Oriental Medicine
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• v.6 no.2
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• pp.87-98
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• 1998

Renal tissues of ICR mouse were intraperitoneally injeced with Monostroma nitidum extract(ME) after Triton WR-1339(TX) injection were observed to investigate the lipid accumulation suppressive effect of ME. The renal tissues were obtained at hour 24, 48, and 72 after TX injection that were fixed in fromol-calcium solution and were cryocut. The tissue stained by H&E for general morphology, sudan black B for lipid and perchloric acid-naphthoquinone method for cholesterol. The parietal layer of Bowman's capsule is swatted as cuboidal type at hour 48 after TX injection and the lipid blot and cholesterol particle were noticeably increased in glomerulus than control group and these appeared in convoluted tubule, collecting tubule, and Helen's loop. But the parietal layer of Bowman's capsule was shaped as squamous type that was looked like as normal morphology in ME treated group after TX injection and the lipid blot and cholesterol particle were considerably decreased in glomerulus than TX group. As results indicated that the accumulation of lipid including cholesterol caused by TX injection were mitigated in renal tissues by the antihyperlipidermic effect of ME.

• The Journal of Dong Guk Oriental Medicine
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• v.7 no.1
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• pp.43-51
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• 1998

Renal tissues of ICR mouse were intraperitoneally injeced with Porpbyra yezoensis extract(PE) after Triton WR-1339(TX) injection were observed to investigate the cholesterol accumulation decreasing effect of PE. The renal tissues were obtained at hour 24, 48, and 72 after TX injection that were fixed in fromol-calcium solution and were cryocut. The tissue stained by sudan black B for lipid and perchloric acid-naphthoquinone method for cholesterol. The parietal layer of Bowman's capsule is swelled as cuboidal type at hour 48 after TX injection and the lipid blot and cholesterol particle were noticeably increased in glomerulus and these appeared in convoluted tubule, collecting tubule, and Helen's loop. In PE treated group, the lpid blot and cholesterol particle were considerably decreased in glomerulus than TX group. As results indicated that the accumulation of lipid including cholesterol caused by TX injection were mitigated in renal tissues by the antihypercholesterolemia effect of PE.