• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.5
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• pp.535-541
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• 2016

A low phase noise META-VCO based-on meta-structure was designed using 65 nm CMOS process. We used a meta-structure to get good phase noise characteristics. The measured phase noises are -67.8 dBc/Hz, -96.37 dBc/Hz, and -107.37 dBc/Hz at 100 kHz, 1 MHz, and 10 MHz offset respectively. The META-VCO operates 8.45~8.77 GHz according to VCTRL, and the output power is -19.12 dBm. The power consumption is 28 mW with 1.2-V supply voltage. The calculated FOM is -140.76 dBc/Hz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12C
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• pp.268-272
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• 2001

In this thesis, PLVCO(Phase Locked Voltage Controlled Oscillator) using 24.42 GHz voltage controlled hair-pin resonator oscillator, Sequency divider, buffer amplifier, -10 dB directional coupler and phase detector is designed and fabricated for B-WLL. The PLVCO shows the oscillator output power of 16.5 dBm at 24.42 GHz, and phase noise of -76.3 dBc/Hz at 1001:Hz offset, -72.8dBc/Hz at 10 kHz offset from fundamental frequency.

• ETRI Journal
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• v.34 no.4
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• pp.518-526
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• 2012

This paper proposes LC voltage-controlled oscillator (VCO) phase-locked loop (PLL) and ring-VCO PLL topologies with low-phase noise. Differential control loops are used for the PLL locking through a symmetrical transformer-resonator or bilaterally controlled varactor pair. A differential compensation mechanism suppresses out-band spurious tones. The prototypes of the proposed PLL are implemented in a CMOS 65-nm or 45-nm process. The measured results of the LC-VCO PLL show operation frequencies of 3.5 GHz to 5.6 GHz, a phase noise of -118 dBc/Hz at a 1 MHz offset, and a spur rejection of 66 dBc, while dissipating 3.2 mA at a 1 V supply. The ring-VCO PLL shows a phase noise of -95 dBc/Hz at a 1 MHz offset, operation frequencies of 1.2 GHz to 2.04 GHz, and a spur rejection of 59 dBc, while dissipating 5.4 mA at a 1.1 V supply.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.4
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• pp.622-629
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• 2001

An engineering model VCO with a good phase noise for Ku-band satellite transponder is designed using a nonlinear design methodology. It generates frequencies from 1,745 and 1,755 MHz with control voltages from 0 to 5 V DC. This unit requires 7 mA of current from 5 V DC supply voltage. Phase noise characteristics of the manufactured VCO exhibit -114 dBc/Hz @10 kHz offset and -131 dBc/Hz @100 kHz of offset and its output power is 5 dBm.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.183-188
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• 2013

Background: Breast cancer (BC), the most common female cancer in Pakistan, is associated with a very high mortality. However, the roles of individual risk factors for BC among Pakistani women are still controversial. To assess potential risk factors for BC, a matched case-control study was conducted in two tertiary care hospitals of Karachi, Pakistan. Materials and Methods: The study population included 297 pathologically confirmed incident cases of BC patients diagnosed between January 2009 and December 2010. 586 controls without any history of BC were matched on hospital and ${\pm}5$ years of ages. Results: Positive family history of BC (MOR=1.72; 95%CI: 1.10, 2.80 for first degree vs. none), single marital status (MOR=1.55; 95%CI: 1.10, 2.39 for single/divorced/widowed women vs. married women), older age at menopause (MOR=3.92; 95%CI: 2.52, 6.18 for menopausal women aged below 45 years, MOR=6.42; 95%CI: 3.47, 11.98 for menopausal women above 45 years of age compared with premenopausal women) conferred an increased risk of BC for women. Increasing parity decreased the risk of BC (MOR=0.90; 95%CI: 0.85, 0.97 for each live birth). Intake of Vitamin D supplements (MOR=0.30; 95%CI: 0.12, 0.81 for ${\leq}3$ years and MOR=0.27; 95%CI: 0.13, 0.56 for >3 years) was protective compared to non-users of Vitamin D. Conclusions: This study confirmed only few of the recognized risk factors in Pakistani women. The protective effect of Vitamin D is important from public health perspective and needs to be further explored through a randomized controlled trial.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5243-5251
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• 2015

Background: To assess women's awareness from diverse sections of society in Delhi regarding various aspects of breast cancer (BC) - perceptions, signs and symptoms, risk factors, prevention, screening and treatment. Materials and Methods: Community-level survey was undertaken in association with the Indian Cancer Society (ICS), Delhi during May 2013-March 2014. Women attending BC awareness workshops by ICS were given self-administered questionnaires before the workshop in the local language to assess BC literacy. Information provided by 2017 women was converted into awareness scores (aware=1) for analysis using SPSS. Awareness scores were dichotomized with median score=19 as cut off, create more aware and less aware categories. Bivariate and multivariate analysis provided P-values, odds ratios (ORs) and 95% confidence intervals (CIs). Results: Broadly, 53.4% women were aware about various aspects of BC. Notably, 49.1% women believed that BC was incurable and 73.9% women believed pain to be an initial BC symptom. Only 34.9% women performed breast self-examination (BSE) and 6.9% women had undergone clinical breast-examination/mammography. 40.5% women had higher awareness (awareness score > median score of 19), which was associated with education [graduates (OR=2.31; 95%CI=1.78, 3.16), post-graduates (OR=7.06; 95%CI=4.14, 12.05) compared to ${\leq}$ high school] and socio-economic status (SES) [low-middle (OR=4.20; 95%CI=2.72, 6.49), middle (OR=6.00; 95%CI=3.82, 9.42) and upper (OR=6.97; 95%CI=4.10, 11.84) compared to low SES]. Conclusions: BC awareness of women in Delhi was suboptimal and was associated with low SES and education. Awareness must be drastically increased via community outreach and use of media as a first step in the fight against BC.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.6
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• pp.339-346
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• 2023

Objectives: This analysis details the characteristics of dental trauma in South Korea during the coronavirus disease 2019 (COVID-19) (DC) pandemic and compares them in patients before and after COVID-19 (BC and AC, respectively). Materials and Methods: Data were collected from medical records of patients who visited Seoul National University Bundang Hospital's Emergency Dental Care Center during three 12-month periods: BC, DC, and AC (BC from March 1, 2019 to February 29, 2020; DC from March 1, 2020 to February 28, 2021; AC from March 1, 2022 to February 28, 2023). A retrospective review was conducted to investigate patient age, sex, time of visit, cause, and diagnosis. The study included 1,544 patients: 660 BC, 374 DC, and 510 AC. Results: Significant difference in age and sex was not observed among the three periods; 1-9 years of age was the largest group (38.3% in BC, 29.6% in DC, and 27.8% in AC), and the percentage of male patients was greater than of female patients (male proportion as 63.5% in BC, 67.4% in DC, and 64.9% in AC). The number of patients generally peaked at a Saturday night in spring (for BC: May, Saturday, 18:00-19:59; for DC: March, Saturday, 18:00-19:59; for AC: April as the second most (October as the most peaked), Saturday, 20:00-21:59). The primary etiology of the dental trauma was identical in the three periods: falls, followed by sports. The most frequent diagnosis was laceration, followed by tooth avulsion and jaw fracture. Conclusion: Significant differences were not found between the characteristics and patterns of dental trauma in the BC, DC, and AC periods. However, due to the pandemic and social distancing, activities decreased and associated dental trauma-related incidents declined.

• 정보화사회
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• s.175
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• pp.12-15
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• 2005

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.7 s.110
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• pp.659-664
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• 2006

This paper reports a high power 60 GHz push-push oscillator fabricated using $0.12{\mu}m$ metamorphic high electron-mobility transistors(mHEMTs). The devices with a $0.12{\mu}m$ gate-length exhibited good DC and RF characteristics such as a maximum drain current of 700 mA/mm, a peak gm of 660 mS/mm, an $f_T$ of 170 GHz, and an $f_{MAX}$ of more than 300 GHz. By combining two sub-oscillators having $6{\times}50{\mu}m$ periphery mHEMT, the push-push oscillator achieved a 6.3 dBm of output power at 59.5 GHz with more than - 35 dBc fundamental suppression. The phase noise of - 81.5 dBc/Hz at 1 MHz offset was measured. This is one of the highest output power obtained using mHEMT technology without buffer amplifier, and demonstrates the potential of mHEMT technology for cost effective millimeter-wave commercial applications.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7445-7449
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• 2013

Background: Breast cancer (BC) is the one of the most common cancers in women. It is also a leading cause of death. Unfortunately, some patients initially present with distant metastases and are diagnosed with stage IV disease that is nearly always, by then, incurable. This retrospective analysis investigated the risk factors for stage IV BC that may underlie such late presentation. Materials and Methods: In all, 916 patients with BC who visited the medical oncology polyclinic of eight different centres in Turkeybetween December 2011 and January 2013 were analysed. Results: A total of 115 patients (12.6%) presented with stage IV disease. In univariate analysis; to comparing these with patients at other stages, no statistical difference was found for median diagnosis age or age at menarche (p=0.611 and p=0.820), whereas age at menopause and age at first live birth were significant (p=0.018 and p=0.003). No difference was detected in terms of accompanying diseases, use of oral contraceptives and hormone replacement therapy, smoking, alcohol consumption and the rate of family history of BC between the patients (p=0.655, p=0.389, p=0.762, p=0.813, p=0.229, p=0.737). However, screening methods were employed less often, the rate of illiteracy was higher, and the rate of other cancers was higher in patients with stage IV BC (p=0.022, p=0.022, p=0.018). No statistical difference was observed between the patients in terms of tumour histopathology, and status of oestrogen receptor, progesterone receptor, or human epidermal growth factor-2 receptor (p=0.389, p=0.326, p=0.949, p=0.326). Grade 3 tumours were more frequent in patients with stage IV disease (p<0.001). On multivariate analysis, risk factors for stage IV breast cancer at the time of presentation were found to be age at first live birth and educational level (p=0.003 and p=0.047). Conclusions: Efforts should be made to perform mammography scans, in particular, at regular intervals through national training programs for all women, particularly those with family histories of breast and other types of cancer, and to establish early diagnosis of BC long before it proceeds to stage IV. Additionally, women's education had better be upgraded. In order to make women aware of BC, national education-programmes must be organised.