• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.863-867
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• 2014

In this study, an acoustic emission (AE) sensor was used for measuring the abrasive and molecular-scale phenomena in chemical mechanical polishing (CMP). An AE sensor is a transducer that converts a mechanical wave into an electrical signal, and is capable of acquiring high-level frequencies from materials. Therefore, an AE sensor was installed in the CMP equipment and the signals were measured simultaneously during the polishing process. In this study, an AE monitoring system was developed for investigating the sensitivity of the AE signal to (a) the variations in the material properties of the pad, slurry, and wafer and (b) the change in conditions during the CMP process. This system was adapted to Oxide and Cu CMP processes. AE signal parameters including AE raw frequency, FFT, and amplitude were analyzed for understanding the abrasive and molecular-level phenomena in the CMP process. Finally, we verified that AE sensors with different bandwidths could function in complementary ways during CMP process monitoring.

• Korean Journal of Optics and Photonics
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• v.19 no.4
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• pp.315-319
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• 2008

We investigate theoretically the power consumption of a notch filter using a thermo-optic long-period grating, which is induced by a heater array consisting of periodic heaters and pads made of metal thin-film. Since the power consumed by the heater array is converted to joule heat that generates the thermo-optic long-period grating, the characteristics of the notch filter are dynamically controlled by adjusting it. The power necessary for appropriate coupling efficiency depends on the parameters of the heater array, which are the width and length of a heater, pad width, and the thickness of the thin-film. We explain an approximate method of analyzing the influence of the parameters on the consumed power. Using the analysis method, we simulate the change of the power depending on the parameters. From the simulation, we suggest a few guidelines on the parameters required to reduce the power.

• Journal of Aerospace System Engineering
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• v.16 no.4
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• pp.77-87
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• 2022

The Precision Aerial Delivery System is an instrument designed to improve the poor landing accuracy of aerial delivery system with conventional circular parachutes, and is equipped with an Airborne Guidance Unit to safely transport supplies to the desired destination. Currently, the landing accuracy of the PADS product is reported as CEP₅₀ 100m and also differs significantly, depending on the actual topography and weather environment. In this study, HILS was constructed based on the 6DOF nonlinear modeling of PADS to analyze the maneuver characteristics of Ram Air Parachute under wind environments. By using the new algorithm a precision soft landing algorithm including Energy Management and Final Approach is designed. HILS results show that it is possible to achieve a precise soft landing within CEP₅₀ 40m, and it can be exploited to develop an actual PADS drop test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.1
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• pp.316-322
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• 2014

The present study investigated the inflammatory hypersensitivity following activation of the transient receptor potential vanilloid receptor-1(TRPV1) in rats. Experiments were carried out on male Sprague-Dawley rats weighing 220-260g. Following an subcutaneous injection of 5% formalin in the orofacial area, nociceptive scratching behavior was recorded for 9 successive 5-min intervals in rats. The subcutaneous injection of $25{\mu}L$ of 5% formalin produced noxious scratching behavior. Injection of capsaicin, TRPV1 agonist, alone into the vibrissa pad did not produced nociceptive behavior. After subcutaneous injection of capsaicin(0$0.1{\mu}g$, $1{\mu}g/10{\mu}L$) in the formalin-treated rats, nociceptive scratching behavior was recorded for 9 successive 5-min internals. Injection of capsaicin into the vibrissa pad significantly increased the number of scratches at 1 hours after injection. Noxious behavioral responses induced by subcutaneous capsaicin injection were significantly potentiated in formalin-treated rats. Pre or post-treatment with iodo-resinaferatoxin(IRTX), TRPV1 antagonist, significantly attenuated increased nociceptive behavior. These findings suggest that activation of the TRPV1 enhanced formalin-induced inflammatory pain in the orofacial area of rats.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.43-49
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• 2010

The effect of sex ratio on behavior and welfare indexes in broiler chickens was investigated. Five variants of the sex ratio (male to female), namely, 100:0 (T1), 75:25 (T2), 50:50 (T3), 25:75 (T4) and 0:100 (T5) were tested in broilers between the ages of 7 to 35 days. It was found that the most common behavior in all sex ratios was resting behavior, ranging over 74.4 % of total behavioral frequency. The ranges of other behavior traits of total behavior traits were as follows: pecking, 5.4 to 23.1 %; standing, 1.8 to 24.8 %, and moving, 0.6 to 11.5 %. The behavioral frequency of resting, pecking, standing and moving were not affected by the sex ratio and between male and female. But the percentage of pecking, resting and moving behavioral frequency was significantly different by the age of birds (P<0.05). Age of birds had no effect on standing behavioral frequency. It seems that gait, food pad and hock burn score were no affect by sex ratio but tend to decreased in female than male. Claw length of 21 and 35 days was not affected by sex ratio and between male and female. The duration of tonic immobility (TI- reaction) was tend to decreased age of 21 than 35 days, and female than male. Both male and female of the study, hock burn score, claw length and TI-reaction were tend to lower in T4 than other treatments. The results suggest that, when male and female broilers are reared together, sex ratio can influence broiler welfare indexes in this study.

• Cartoon and Animation Studies
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• s.30
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• pp.221-243
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• 2013

Recently, traditional books based on printing on the paper have expanded to e-book media in smart device because of developing digital technology. Especially, app book applied application makes users' experience increase and provides immersion to them, because it allows them basically delivering information, educational effect and fun elements with multimedia technology. There are various experimental trials to make enhance effect of reformatting for application media. The purpose of this study is to analyze reformatting effect for app book with funology which is convergence of digital technology and a fun. Then this article would provide design guide and be applied to new application contents. For this research, the first of all, we would discuss concept and elements of funology by publication including thesis, articles, and books. Secondly, this article will be focused on 'Moo, Baa, La La La!' which is reformatting application for iPad to analyze type of funology. Thirdly, we would make sure that app book makes users get emotional effect comparing original book by FGI(Focus Group Interview). In conclusion, sensitive funology used the sound allows user emotional effect and they prefer to intuitive and immediate motion and response of interactive funology. In other way, funology of fun in itself which is strong concept in original book diminishes in app book. Then users concentrate interactive factors like game structure. This results make that app books could be created by strength of original contents and advantage of funology. Therefore this makes us expect the possibility of reformatting effect with funology and we need to discuss the points of issue that there are considerations and limitations to successful app book for users.

• 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 $0.64mm^2$.

• Science of Emotion and Sensibility
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• v.16 no.4
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• pp.469-480
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• 2013

In this paper, we propose new method to reduce variance and express mixed feelings in Russell's emotional dimension(A Circumplex model). A Circumplex model shows mean and variance of emotions(joy, sad, happy, enjoy et. al.) in PAD(Pleasure, Arousal, Dominace, et. al.) dimension using self-diagnostic method(SAM: Self-Assessment-Manikin). But other researchers consistently insisted that Russell's model had two problems. First, data(emotional words) gathered by Russell's method have too big variance. So, it is difficult to separate valid value. Second, Russell's model can not properly represent mixed feelings because it has structural problem(It has a single Pleasure dimension). In order to solve these problems, we change survey methods, so that we reduce value of variance. And then we conduct survey(which can induce mixed feelings) to prove Positive/Negative(Pleasure) part in emotion and confirm that Russell's model can be used to express mixed feelings. Using this method, we can obtain high reliability and accuracy of data and Russell's model can be applied in many other fields such as bio-signal, mixed feelings, realistic broadcasting, et. al.

• Journal of the Microelectronics and Packaging Society
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• v.14 no.1
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• pp.33-38
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• 2007

We studied a bonding at low temperature using polymer bump and Non-Conductive Adhesive (NCA), and studied the reliability of the polymer bump/Al pad joints. The polymer bumps were formed on oxidized Si substrates by photolithography process, and the thin film metals were formed on the polymer bumps using DC magnetron sputtering. The substrate used was AL metallized glass. The polymer bump and Al metallized glass substrates were joined together at $80^{\circ}C$ under various pressure. Two NCAs were applied during joining. Thermal cycling test ($0^{\circ}C-55^{\circ}C$, cycle/30 min) was carried out up to 2000 cycles to evaluate the reliability of the joints. The bondability was evaluated by measuring the contact resistance of the joints through the four point probe method, and the joints were observed by Scanning Electron Microscope (SEM). The contact resistance of the joints was $70-90m{\Omega}$ before the reliability test. The joints of the polymer bump/Al pad were damaged by NCA filler particles under pressure above 200 MPa. After reliability test, some joints were electrically failed since thinner metal layers deposited at the edge of bumps were disconnected.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.2
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• pp.109-114
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• 2021

The characteristics of vibrational stress (shock and vibration) during transport and the possibility of damage to the packaged pears by functional PLA tray were investigated. And this study was conducted to analyze how environmental conditions by simulated transport environment affect quality factors such as weight loss (%) and soluble solid content (SSC, %), and firmness (bioyield strength, kPa) of packaged pears by PLA tray and Expanded PET foam pad (Group 1), EPE cushion cup pad and net (Group 2) for exporting. Pears with or without vibration stress were stored for 30 days at low temperatures (5 ± 0.8℃, 80 ± 5% relative humidity). There was the statistically significant difference (p ≤ 0.05) between pears with and without vibration stress for weight loss, soluble solid content, and firmness (bioyield strength) after 30 days storage. Vibration stress accelerated pear quality deterioration during storage, resulting in increased weight loss, soluble solids content, and reduced hardness. The firmness (bioyield strength) and weight changes of pears with PLA trays were smaller than those of conventional packaging box systems. It was determined that the firmness of agricultural products was a quality factor closely related to the storage period and that PLA could be applied.