• 대한전자공학회논문지SP
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• 제41권4호
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• pp.103-111
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• 2004

화자 정규화 방법은 화자 독립 음성인식 시스템에서 음성 인식의 정확성을 높이기 위한 성공적인 방법으로 알려져 왔다. 널리 사용되는 화자 정규화 방법은 maximum likelihood 반의 주파수 warping 방법이다. 본 논문은 주파수 warping 보다 더 좋은 화자 정규화의 성능 개선을 위해 새로운 파워 스펙트럼 warping 방법을 제안한다. 파워 스펙트럼 warping은 멜 주파수 켑스트럼 분석(MFCC) 방법을 이용하며, MFCC 처리 단계에서 필터 뱅크의 파워 스펙트럼을 조절함으로써 화자 정규화를 수행하는 간단한 메커니즘으로 갖는다. 또한 본 논문은 파워 스펙트럼 warping과 주파수 warping 방법을 서로 결합한 hybrid VTN 방법을 제안한다. 본 논문의 실험은 baseline 시스템에 각 화자 정규화 방법을 적용하여 SKKU PBW DB에서 인식 성능을 비교 분석하였다. 실험 결과를 보면 baseline 시스템의 단어 인식 성능을 기준으로 주파수 warping은 2.06%, 파워 스펙트럼 warping은 3.05%, 그리고 hybrid VTN은 4.07%의 단어 에러 율의 감소를 보였다.

• 지역사회간호학회지
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• 제19권4호
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• pp.704-714
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• 2008

Purpose: This study explored the feasibility of a 12 week self-efficacy based exercise intervention for overweight and obese college students. Method: A repeated measure, 4-group randomized controlled design was used. Students were recruited from two universities. in Seoul. Korea using: (1) flyers either on the campus bulletin boards or in campus restrooms: (2) advertisement on campus e-board: and (3) self-referral. Inclusion criteria were: (1) Korean college students aged 18 to 29: (2) BMI >23: (3) viscerally obese: and (4) accessible to a phone and a computer. Participants completed three self-reported questionnaires: socio-demographic questionnaire (at the baseline), Exercise Self-Efficacy Scale (at the baseline and $12^{th}$ week), and Physical Fitness sub-subscale (at the baseline and $12^{th}$ week). Additionally. physiological data (height, weight, blood pressure) were collected at the baseline and $12^{th}$ week. Descriptive statistics and a two-way mixed ANOVA were performed using SPSS12.0. Results: No significant group difference was observed. However. students with increased exercise self-efficacy during the program showed better physical fitness in the $12^{th}$ week. When students' physical fitness was enhanced. the physiological factors were improved. Conclusions: Self-efficacy based exercise intervention may be applicable and acceptable to the college students. It is necessary to conduct a replicated study with a larger sample and an elongated intervention period.

• Progress in Superconductivity
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• 제7권1호
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• pp.6-10
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• 2005

We have studied feasibility of single-layer second-order $high-T_c$ SQUID gradiometers in magnetocardiography. We have measured human cardiomagnetic signals using a short-baseline (5.8 mm) single-layer second-order YBCO gradiometer in partially shielded environments. The gradiometer has an overall size of $17.6\;mm{\times}6\;mm$ and contains three parallel-connected pickup coils which are directly coupled to a step-edge junction SQUID. The gradiometer showed an unshielded gradient noise of $0.84\;pT/cm^2/Hz^{1/2}$ at 1 Hz, which corresponds to an equivalent field noise of $280\;fT/Hz^{1/2}$. The balancing factor was $10^3$. Based on the same design rules as the short-baseline devices, we have studied fabrication of 30 mm-long baseline gradiometers. The devices had an overall size of $70.2\;mm{\times}10.6\;mm$ with each pickup coil of $10\;mm{\times}10\;mm$ in outer size. As Josephson elements we made two types of submicron bridges, which are variable thickness bridge (VTB) and constant thickness bridge (CTB), from $3\;{\mu}m-wide$ and 300 nm-thick YBCO lines with a thin layer of Au on top by using a focused ion beam (FIB) patterning method. VTB was 300 nm wide, 200 nm thick, 30 nm long with Au removed and CTB 100 nm wide and 30 nm long. In temperature-dependent critical currents, $I_c(T)$, VTB showed an nonmetallic barrier-type behavior and CTB an SNS behavior. We believe that those characteristics are ascribed to naturally formed grain boundaries crossing the bridges.

• Journal of Periodontal and Implant Science
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• 제34권3호
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• pp.509-522
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• 2004

This study was performed to compare the clinical effectiveness of two regenerative techniques for class II furcation involvements in human: a combination of bone grafts with PRP vs. GTR with bone grafts. The e-PTFE group was treated with non-absorbable membrane and bone grafts, the PRP group was treated with PRP and bone grafts Pocket depth, clinical attachment level, and gingival recession were measured at baseline and postoperative 6 months. Vertical and horizontal furcation depth were measured by re-entry surgeries at 6 months post-treatment Both groups were statistically analyzed by Wilcoxon signed Ranks Test & Mann-whitney Test using SPSS program (5% significance level). The results were as follows: 1. The change of pocket depth, clinical attachment level, vertical furcation depth and horizontal furcation depth in both groups was decreased significantly at 6 months than at baseline. (p<0.05) 2. The change of gingival recession in both groups was increased significantly at 6 months than at baseline. (p<0.05) 3. The change of alveolar crest absorption in both groups was increased at 6 months than at baseline but there were no statistically significant differences. 4. The change of pocket depth, clinical attachment level, vertical furcation depth and horizontal furcation depth in both groups was increased significantly at 6 months, but there were no statistically or clinically significant differences with both groups. 5. The change of gingival recession and alveolar crest absorption in both groups was increased at 6 months, but there were no statistically or clinically significant differences with both groups. In conclusion, the use of bone graft with PRP or GTR technique improved clinical index of the soft and hard tissue in mandibular class II furcation involvement but there were no statistically or clinically significant differences between bone graft with PRP and GTR technique.

• 한국의학물리학회지:의학물리
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• 제30권1호
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• pp.22-31
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• 2019

Purpose: To develop a new diffusion-based functional MRI (fMRI) sequence to generate apparent diffusion coefficient (ADC) maps in single excitation and evaluate the contribution of b0 signal on neuronal changes. Materials and Methods: A diffusion-based fMRI sequence was designed with single measurement that can acquire images of three directions at a time, obtaining $b=0s/mm^2$ during the first baseline condition (b0_b), followed by 107 diffusion-weighted imaging (DWI) with $b=600s/mm^2$ during the baseline and visual stimulation conditions, and another $b=0s/mm^2$ during the last activation condition (b0_a). ADC was mapped in three different ways: 1) using b0_b (ADC_b) for all time points, 2) using b0_a (ADC_a) for all time points, and 3) using b0_b and b0_a (ADC_ba) for baseline and stimulation scans, respectively. The fMRI studies were conducted on the brains of 16 young healthy volunteers using visual stimulations in a 3T MRI system. In addition, the blood oxygen level dependent (BOLD) fMRI was also acquired to compare it with diffusion-based fMRI. A sample t-test was used to investigate the voxel-wise average between the subjects. Results: The BOLD data consisted of only activated voxels. However, ADC_ba data was observed in both deactivated and activated voxels. There were no statistically significant activated or deactivated voxels for DWI, ADC_b, and ADC_a. Conclusions: With the new sequence, neuronal activations can be mapped with visual stimulation as compared to the baseline condition in several areas in the brain. We showed that ADC should be mapped using both DWI and b0 images acquired with the same conditions.

• Journal of Yeungnam Medical Science
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• 제35권2호
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• pp.205-212
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• 2018

Background: Brain volume is associated with dementia and depression in the elderly. An easy way to predict relative brain volume is to measure head circumference. In this study, we investigated the relationship between head circumference and cognition as well as depression in a non-demented elderly community. Methods: Baseline and follow-up surveys were conducted in 2007 and 2010. At baseline, community residents aged 65 years or over (n=382) within a rural area of South Korea were screened for dementia and symptoms of depression and were followed using the same screening battery after 3 years (n=279). Data from anthropometric measurements (head circumference, height, and body weight), demographics, and blood tests were gathered. Neuropsychological tests, including the Korean version of mini-mental state examination (K-MMSE), clinical dementia rating (CDR) including the CDR-sum of boxes, the Korean version of instrumental activities of daily living, and geriatric depression scale (GDS), were performed. None of the 279 subjects followed were demented. Results: Baseline performance on the K-MMSE and GDS was poorer for participants with smaller head circumferences. Follow-up performance on the MMSE was also poorer for participants with smaller head circumferences. Interestingly, participants with smaller head circumference showed worse GDS scores at baseline but on follow-up examination, participants with larger head circumference showed rapid worsening than those with smaller head circumference with marginal significance by ANOVA test. In regression coefficient analysis, GDS decline showed significant difference. Conclusion: Head circumference was not associated with cognitive change but was associated with symptoms of depression in non-demented community residents.

• 우주기술과 응용
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• 제2권3호
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• pp.221-229
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• 2022

본 논문에서는 온도에 민감한 플럭스게이트 자력계 센서 온도를 일정하게 유지하기 위한 온도 조절 장치의 설계 및 설치, 그리고 설치 이후 데이터 안정성 평가에 대하여 기술하였다. 온도 조절 장치는 국립전파연구원 우주전파센터에서 운영 중인 이천 지자기 관측소에 설치되었다. 온도 조절 장치는 사고 안정성, 자기장 측정에 미치는 영향, 온도 조절 효율을 고려하여 설계하였다. 온도 조절 장치 설치 이후, 온도가 20℃ 수준에서 일정하게 유지되는 것을 확인하였다. 지자기 데이터 안정성 평가를 위하여 델타 F(delta-F)와 베이스라인(baseline) 값을 이용하였으며, 장치 설치 이후 델타 F와 베이스라인의 변동이 줄어든 것을 확인하였다.

• The Korean Journal of Pain
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• 제37권2호
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• pp.132-140
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• 2024

Background: This study aimed to identify exact anatomical landmarks and ideal injection volumes for safe adductor canal blocks (ACB). Methods: Fifty thighs from 25 embalmed adult Korean cadavers were used. The measurement baseline was the line connecting the anterior superior iliac spine (ASIS) to the midpoint of the patellar base. All target points were measured perpendicular to the baseline. The relevant cadaveric structures were observed using ultrasound (US) and confirmed in living individuals. US-guided dye injection was performed to determine the ideal volume. Results: The apex of the femoral triangle was 25.3 ± 2.2 cm distal to the ASIS on the baseline and 5.3 ± 1.0 cm perpendicular to that point. The midpoint of the superior border of the vasto-adductor membrane (VAM) was 27.4 ± 2.0 cm distal to the ASIS on the baseline and 5.0 ± 1.1 cm perpendicular to that point. The VAM had a trapezoidal shape and was connected as an aponeurosis between the medial edge of the vastus medialis muscle and lateral edge of the adductor magnus muscle. The nerve to the vastus medialis penetrated the muscle proximal to the superior border of the VAM in 70% of specimens. The VAM appeared on US as a hyperechoic area connecting the vastus medialis and adductor magnus muscles between the sartorius muscle and femoral artery. Conclusions: Confirming the crucial landmark, the VAM, is beneficial when performing ACB. It is advisable to insert the needle obliquely below the superior VAM border, and a 5 mL injection is considered sufficient.

• Journal of Periodontal and Implant Science
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• 제51권3호
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• pp.199-212
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• 2021

Purpose: This randomized clinical placebo-controlled trial was conducted to evaluate the effectiveness of Lactobacillus reuteri as a probiotic in guided pocket recolonization (GPR) for the treatment of chronic periodontitis (CP) adjunctive to scaling and root planing (SRP). Methods: Forty-eight CP patients were randomly assigned to 3 treatment groups: group 1 (SRP+placebo), group 2 (SRP+single application of probiotic), and group 3 (SRP+incremental application of probiotic). Clinical parameters were evaluated at baseline and at 8, 12, and 24 weeks, whereas biochemical parameters were measured at baseline and 12 weeks. Results: At 24 weeks, the probing pocket depth and clinical attachment level improved in all 3 groups from baseline with no significant intergroup differences; however, a statistically significant difference was observed in localized plaque and gingival scores between groups 1 and 3 (P<0.05). At 12 weeks, matrix metalloproteinase-8 (MMP-8), nitric oxide (NO), and gingipains-R (Rgps) levels improved in all 3 groups, with statistically significant differences between groups 1 and 3 for MMP-8 and NO (P<0.05), but no difference for Rgps levels. Conclusions: Within its limitations, the results of this study show that incremental 3-time application of L. reuteri as a probiotic led to improvements in clinical and biochemical parameters. This protocol can be a useful adjunct to SRP in the non-surgical management of CP.

• 한국측량학회지
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• 제25권5호
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• pp.437-449
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• 2007

우리나라 국토지리정보원에서는 3등측지기준점의 세계측지계 전환을 위해 1997년에서 2005년까지 총 69개 사업지구에서 관측된 약 11,000여개 삼각점의 GPS관측데이터를 확보하였다. 본 연구에서는 3등측지기준점 관측데이터와 관련된 사항을 요약하고, 연도별 사업지구별 데이터를 분석한 후 40개 지구의 데이터를 재처리하였다. 또한, 과대오차 검출과 통계모델의 추정을 위해 사업지구별로 최소제약조건에 의한 망조정을 실시하고 추정한 정확도는 수평 $5mm{\pm}0.5ppm$ 수직 $10mm{\pm}1ppm$을 얻었다. 한국측지계 2002(KGD2002)의 최종성과 산정을 위한 GPS망조정은 GPS기선벡터를 기선해석 S/W별로 구분하여 총 17개의 블록으로 구성하고 블록별 최소제약 조정에 의해 평가하였으며, 다점고정 조정에 따라 최종성과를 산정하고 절대정확도 점검을 실시하였다.