• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.4
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• pp.259-267
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• 1986

The small-signal S-parameters of GaAs MESFET are measured in terms of frequencies and bias conditions. The resonating network and the load matching network of the fixed-frequency microwave oscillator analyzed by two-port network analysis are designed by the optimum method of CAD. The 6GHz oscillator circuit is built and tested on the microstrip substrates. Finally, it is verified that the experimenta results conformed to the optimum data by CAD.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.775-778
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• 1987

Double-diffused metal oxide power semiconductor field effect transistors are used extensively in recent years in various circuit applications. The temperature variation of the drain current at a fixed bais shows both positive and negative resistance characteristics depending on the gate threhold voltage and gate-to source bias voltage. In this study, the decision method of the internal temperature measurement by $V_{GS}$ and $V_{DS}$ are presented.

• Journal of Electrical Engineering and Technology
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• v.7 no.2
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• pp.221-224
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• 2012

We propose a Readout Integrated Circuit (ROIC), which applies a fixed current bias sensing method to the input stage in order to simplify the circuit structure and the infrared sensor characteristic control. For the sample-and-hold stage to display and control a signal detected by the infrared sensor using a two-dimensional (2D) focal plane array, a differential delta sampling (DDS) circuit is proposed, which effectively removes the FPN. In addition, the output characteristic is improved to have wider bandwidth and higher gain by applying a two-stage variable gain amplifier (VGA). The output characteristic of the proposed device was 23.91 mV/$^{\circ}C$, and the linearity error rate was less than 0.22%. After checking the performance of the ROIC using HSPICE simulation, the chip was manufactured and measured using the SMIC 0.35 um standard CMOS process to confirm that the simulation results from the actual design are in good agreement with the measurement results.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.240-242
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• 1994

Spectroscopic ellipsometry(SE) was employed to characterize the Si/$Si_{1-x}Ge_x$ heterostructure. The dielectric function spectrum of $Si_{1-x}Ge_x$ at an arbitrary x value in the spectral range of $1.5{\sim}4.5\;eV$ was computed by EMA (effective medium approximation) model using the available optical constants measured at a number of fixed x values of Ge composition. The thickness and the Ge composition of $Si_{1-x}Ge_x$ measured by SE was compared with those measured by RBS. DC bias effect on the $E_2$ peak of dielectric function spectra was studied.

• Journal of Hospice and Palliative Care
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• v.24 no.3
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• pp.144-153
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• 2021

Purpose: Advance care planning (ACP) is widely understood to improve end-of-life care. This systematic review and meta-analysis aimed to examine the effects of ACP interventions on decision conflict and psychological distress. Methods: A search of PubMed, CINAHL, CENTRAL, EMBASE, KISS, KoreaMed, and RISS was conducted in November 2020. The study included randomized controlled trials. Data were pooled using fixed- and random-effects models. Results: Fourteen studies were identified that cumulatively included 1,548 participants. ACP interventions were effective in alleviating decision conflict (d=-0.53; 95% CI: -0.83 to -0.23), depression (d=-1.22; 95% CI: -1.71 to -0.74) and anxiety (d=-0.76; 95% CI: -1.12 to -0.39). Conclusion: ACP interventions have significant positive effects on reducing decision conflict and psychological distress. A high level of bias was shown related to allocation concealment and blinding. The results of this study are expected to be useful for end-of-life care providers to improve the effectiveness of ACP interventions.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7203-7206
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• 2013

Recent studies suggested that the ovarian cancers with negative excision repair cross-complementation group 1 enzyme (ERCC1) expression have a better response to platinum-based chemotherapy than those with positive ERCC1 expression. The objective of this study was to evaluate whether ERCC1 expression is associated with response to platinum-based chemotherapy in ovarian cancers. MEDLINE, PubMed, Web of Science and CNKI databases were used for searching studies relating to ERCC1 protein expression and response to platinum-based chemotherapy in ovarian cancers. Statistical analysis was based on the method for a fixed effects meta-analysis. Pooled odds ratios (ORs) with 95% confidence intervals for ERCC1 protein expression and response to platinum-based chemotherapy were generated. Publication bias was investigated with Begg's test. Five studies involving 306 patients with ovarian cancer were included. Compared to patients with positive ERCC1 expression, those with negative ERCC1 expression had a better response to platinum-based chemotherapy. The pooled OR was 5.264 (95% CI: 2.928-9.464, P < 0.001) and publication bias was not found (P = 0.904). The result was similar in both in Asians and Caucasians (P < 0.001 and P = 0.028, respectively). ERCC1 protein expression status is significantly associated with response to platinum-based chemotherapy in ovarian cancers.

• Corrosion Science and Technology
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• v.18 no.5
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• pp.206-211
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• 2019

Silicon carbide (SiC) thin films become superhard when they have microstructures of nanocolumnar crystalline grains (NCCG) with an intergranular amorphous SiC matrix. We investigated the role of ion bombardment and deposition temperature in forming the NCCG in SiC thin films. A direct-current (DC) unbalanced magnetron sputtering method was used with pure Ar as sputtering gas to deposit the SiC thin films at fixed target power of 200 W and chamber pressure of 0.4 Pa. The Ar ion bombardment of the deposited films was conducted by applying a negative DC bias voltage 0-100 V to the substrate during deposition. The deposition temperature was varied between room temperature and $450^{\circ}C$. Above a critical bias voltage of -80 V, the NCCG formed, whereas, below it, the SiC films were amorphous. Additionally, a minimum thermal energy (corresponding to a deposition temperature of $450^{\circ}C$ in this study) was required for the NCCG formation. Transmission electron microscopy, Raman spectroscopy, and glancing angle X-ray diffraction analysis (GAXRD) were conducted to probe the samples' structural characteristics. Of those methods, Raman spectroscopy was a particularly efficient non-destructive tool to analyze the formation of the SiC NCCG in the film, whereas GAXRD was insufficiently sensitive.

• Cartoon and Animation Studies
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• s.16
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• pp.101-112
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• 2009

The purpose of this study is to analyze trilogy by means of semiotics. trilogy constructs a story as a whole while each piece delivers a concluded ending. This study used 'modele actantiel' and 'carre semiotique' of Greimas in order to clarify not only the meaning structure but also the course of narrative of . is a compelling story which reverses the fairy tale of a beautiful princess and a heroic prince. Each piece of the trilogy unfolds as following; (1)ls the love of a princess and an ogre possible? (2)Can the marriage of the couple get confirmed? (3)Can Shrek be free again? The repeated meaning structure of trilogy is the binary opposition of nature versus culture, and the narrative course forms the meaning square on the basis of the opposition. Human culture represented by the lord Farquaad and Duloc castle signifies cleanness, order, complex, anxiety, paranoia, authoritarian, and violent. On the contrary, Nature represented by Shrek and the swamp signifies barbarity, freedom, confident, maturity, unstrained, and humar. The meaning of Shrek series is generated by the structure of the basic discrimination of culture versus nature. However, as story twists the bias and fixed idea, the meaning structure of Shrek shows a unique relationship of culture and nature. Although Shrek, an ogre, lives alone in a swamp because of the bias of human world, he is depicted as self-sufficient, comfort, and broad-minded. On the basis of this meaning structure, Shrek is not a story that an ogre(nature) strives to enter the human culture, nor a story that nature wins a victory at the confrontation between culture and nature, but a story that human(culture) and ogre(nature) overcome their fixed ideas through the transition from culture to nature and vice versa.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.1982-1990
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• 1994

We implemented a PLDRO(Phase Locked Dielectric Resonator Oscillator) using the concept of the feedback property of PLL(Phase Locked Loop) for Ku-band(10.95-11.70 GHz). The conventional approaches to a PLDRO design use varactor diode tuning method.. But in theis paper, the PLDRO has the advantage of the frequency sensitivity to changes in the supple voltage of the oscillating device without the frequency-variable part by varactor diode voltage-control. and uses a SPD(Sampling Phase Detector) for phase-comparision. The PLDRO is composed of the DRO phase-locked to the reference signal of UHF band by using a SPD for high frequency stability and can be available for European FSS(Fixed Satellite Service) at 10.00GHz. The PLDRO generates the output power of 8.67 dBm at 10.00 GHz and has a phase noise of -81 dBc/Hz at 10 kHz offset from carrier. The hamonic and spurious characteristics have -42.33 dBc and -65dBc respectively. This PLDRO has much better frequency stability, lower phase noise, and more economical effect for a satellite system than conventional DRO.

• Journal of Korean society of Dental Hygiene
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• v.20 no.3
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• pp.269-279
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• 2020

Objectives: Previous studies have reported inconsistent findings in the association between dental diagnostic X-ray exposure and thyroid cancer. This study was a meta-analysis of case-control studies evaluating the association between exposure to dental radiation and the thyroid cancer risk. Methods: We searched the PubMed and EMBASE databases to identify studies on dental radiation and thyroid cancer risks that were published up to September 2018. Quality of studies was assessed using the Newcastle-Ottawa scale. A fixed-effects model was used to estimate pooled odds ratios (ORs) and 95% confidence intervals (CIs) using STATA 14.0. Potential publication biases were evaluated using Egger's test and Begg's funnel plot. Results: From the literature search, we included six case-control studies in this meta-analysis. The meta-analysis using the fixed-effects model found that dental X-ray exposure was associated with 2.34 times increased risk for thyroid cancer (OR=2.34, 95% CI=1.79-3.21). There was no heterogeneity in the data (p=0.662, I² =0%). Egger's test showed that there was no publication bias (p=0.532). Conclusions: This meta-analysis confirmed the association of dental X-ray exposure and thyroid cancer risk. The current results underscore the importance of applying safety regulations at dental clinics to protect thyroid glands during dental radiography examinations.