• 제목/요약/키워드: threshold methods

검색결과 1,513건 처리시간 0.034초

Compressed Demographic Transition and Economic Growth in the Latecomer

  • Inyong Shin;Hyunho Kim
    • 분석과 대안
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    • 제7권2호
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    • pp.35-77
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    • 2023
  • This study aims to solve the entangled loop between demographic transition (DT) and economic growth by analyzing cross-country data. We undertake a national-level group analysis to verify the compressed transition of demographic variables over time. Assuming that the LA (latecomer advantage) on DT over time exists, we verify that the DT of the latecomer is compressed by providing a formal proof of LA on DT over income. As a DT has the double-kinked functions of income, we check them in multiple aspects: early maturation, leftward threshold, and steeper descent under a contour map and econometric methods. We find that the developing countries (the latecomer) have speedy DT (CDT, compressed DT) as well as speedy income such that DT of the latecomers starts at lower levels of income, lasts for a shorter period, and finishes at the earlier stage of economic development compared to that of developed countries (the early mover). To check the balance of DT, we classify countries into four groups of DT---balanced, slow, unilateral, and rapid transition countries. We identify that the main causes of rapid transition are due to the strong family planning programs of the government. Finally, we check the effect of latecomer's CDT on economic growth inversely: we undertake the simulation of the CDT effect on economic growth and the aging process for the latecomer. A worrying result is that the CDT of the latecomer shows a sharp upturn of the working-age population, followed by a sharp downturn in a short period. Compared to early-mover countries, the latecomer countries cannot buy more time to accommodate the workable population for the period of demographic bonus and prepare their aging societies for demographic onus. Thus, we conclude that CDT is not necessarily advantageous to developing countries. These outcomes of the latecomer's CDT can be re-interpreted as follows. Developing countries need power sources to pump up economic development, such as the following production factors: labor, physical and financial capital, and economic systems. As for labor, the properties of early maturation and leftward thresholds on DTs of the latecomer mean that demographic movement occurs at an unusually early stage of economic development; this is similar to a plane that leaks fuel before or just before take-off, with the result that it no longer flies higher or farther. What is worse, the property of steeper descent represents the falling speed of a plane so that it cannot be sustained at higher levels, and then plummets to all-time lows.

Effects of Residual Hearing on the Auditory Steady State Response for Cochlear Implantation in Children

  • Kim, Young Seok;Han, Sun A;Woo, Hyunjun;Suh, Myung-Whan;Lee, Jun Ho;Oh, Seung Ha;Park, Moo Kyun
    • Journal of Audiology & Otology
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    • 제23권3호
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    • pp.153-159
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    • 2019
  • Background and Objectives: We aim to explore the effects of residual auditory steady state response (ASSR) on cochlear implantation (CI) outcomes in children lacking auditory brainstem responses (ABRs). Subjects and Methods: We retrospectively reviewed the data of child CI recipients lacking ABRs. All ears were divided into two groups: with residual ASSR and without ASSR. For each frequency, the T- and C-levels and the electrical dynamic ranges of postoperative 3-month and 1-year mappings were compared between the groups. To evaluate speech perception, patients who received simultaneous bilateral CIs were divided into two groups: group 1 exhibited responses at all frequencies in both ears; in group 2, at least one ear evidenced no response. The Categories of Auditory Perception (CAP) and Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) scores were compared between the groups. Results: We enrolled 16 patients. At 2 kHz, the postoperative 3-month and 1-year T-levels of patients with residual hearing were lower than those of hearing loss group (p=0.001, p=0.035). In residual hearing group, the ASSR threshold correlated positively with the postoperative 1-year T-level (p=0.012, R2=0.276) and C-level (p=0.002, R2=0.374). Of 10 simultaneous bilateral CI recipients, 5 exhibited ASSRs at all frequencies and the other 5 showed no response at ≥1 frequency. The latter had higher CAP scores at the postoperative 1-year (p=0.018). Conclusions: In children exhibiting hearing loss in ABR testing, residual hearing at 2 kHz ASSR correlated positively with the post-CI T-level. Those with ASSRs at all frequencies had significantly lower CAP scores at the postoperative 1year. CI should not be delayed when marginal residual hearing is evident in ASSR.

도시부 도로상의 진출입부 접속형태 결정에 관한 연구 (Determination on Connection Type of Entrance/Exit on Urban Roads)

  • 이형무;권성대;오석진
    • 대한토목학회논문집
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    • 제43권2호
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    • pp.219-230
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    • 2023
  • 도시의 토지이용은 지속적으로 고도화, 광역화 추세로 도로와 접한 주변 토지들은 다양한 용도의 시설물 건설과 함께 진출입부 접속도 증가하고 있다. 그러나 구체적인 진출입부 설치 기준이 없는 상황에서 부적절한 접속위치와 접속형태, 그리고 운영방식은 기존 가로 및 교차로의 교통 서비스수준을 악화시키고 있다. 이에 본 연구는 도시부 보조간선도로와 집산도로에 접속되는 진출입부의 교통상의 영향 최소화를 위해 첫째, 진출입부와 접한 도로·교통 환경을 고려하여 상·하류부 교차로의 대기행렬 길이와 진출입부에서 교차로간 차로변경에 필요한 소요길이를 재정립하여 기존 상·하류 교차로 사이에서 물리적으로 접속 가능한 진출입부 접속위치 및 접속형태 결정 기준을 제시하였다. 둘째, 진출입부 접속형태(신호교차로, 단순접속교차로)에 따른 좌회전차로와 가·감속차로의 교통시설 설치 비용과 진출입부 설치 전·후의 교통 비용의 차이인 부(-)의 사회적 비용을 통해 사업지 임계유발량을 산정한 후 주변 교차로 서비스수준과의 관계로부터 진출입부 운영방식을 정량적으로 결정할 수 있음을 제시하였다.

일개 종합병원을 방문한 어선원에서 발생한 소음성 난청의 특징 (Characteristics of Noise Induced Hearing Loss of Fishermen Visiting a General Hospital)

  • 정유선;김창회
    • 농촌의학ㆍ지역보건
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    • 제48권1호
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    • pp.41-49
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    • 2023
  • 2022년 11월부터 2023년 2월까지 동국대학교 경주병원 이비인후과 외래를 내원한 환자 중에서 소음성 난청을 가진 어선원의 의무기록을 후향적으로 검토하여 소음성 난청을 가진 총 10명의 19개 귀의 청각학적 특성을 분석하였다. 모두 60세 이상의 남자였고 소음에 노출된 기간은 평균적으로 38.9 ± 10.8년으로 장기간 소음에 노출되었으나 난청기간은 평균적으로 13.4 ± 4.3년으로 소음노출에 비해서 늦게 난청을 인지하였다. 고음역 평균역치가 저음역 평균역치보다 높지만, 8 kHz에서 하강하는 청력도를 보였고 고음역 평균 청력역치가 75 dB 초과인 경우는 10.5%이나 저음역 평균 청력역치가 40 dB 초과인 경우가 57.9%를 차지하였다. 순음청력검사상 평균 청력역치는 52.2 ± 7.1 dB, 어음청취역치는 34.0 ± 11.1 dB, 어음명료도검사는 81.5 ± 11.4%, 청성뇌간반응검사의 청력역치는 56.8 ± 6.7 dB, 청성지속반응검사의 청력역치는 63.7 ± 7.6 dB였다. 향후 다기관 연구에서는 어선의 소음의 크기 및 근로시간 등 근로환경에 대한 조사를 같이 시행하여 소음노출을 확인 후 어선원 소음성 난청 청각학적 특성을 분석해야 할 것이다.

Effects of Residual Hearing on the Auditory Steady State Response for Cochlear Implantation in Children

  • Kim, Young Seok;Han, Sun A;Woo, Hyunjun;Suh, Myung-Whan;Lee, Jun Ho;Oh, Seung Ha;Park, Moo Kyun
    • 대한청각학회지
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    • 제23권3호
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    • pp.153-159
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    • 2019
  • Background and Objectives: We aim to explore the effects of residual auditory steady state response (ASSR) on cochlear implantation (CI) outcomes in children lacking auditory brainstem responses (ABRs). Subjects and Methods: We retrospectively reviewed the data of child CI recipients lacking ABRs. All ears were divided into two groups: with residual ASSR and without ASSR. For each frequency, the T- and C-levels and the electrical dynamic ranges of postoperative 3-month and 1-year mappings were compared between the groups. To evaluate speech perception, patients who received simultaneous bilateral CIs were divided into two groups: group 1 exhibited responses at all frequencies in both ears; in group 2, at least one ear evidenced no response. The Categories of Auditory Perception (CAP) and Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) scores were compared between the groups. Results: We enrolled 16 patients. At 2 kHz, the postoperative 3-month and 1-year T-levels of patients with residual hearing were lower than those of hearing loss group (p=0.001, p=0.035). In residual hearing group, the ASSR threshold correlated positively with the postoperative 1-year T-level (p=0.012, R2=0.276) and C-level (p=0.002, R2=0.374). Of 10 simultaneous bilateral CI recipients, 5 exhibited ASSRs at all frequencies and the other 5 showed no response at ≥1 frequency. The latter had higher CAP scores at the postoperative 1-year (p=0.018). Conclusions: In children exhibiting hearing loss in ABR testing, residual hearing at 2 kHz ASSR correlated positively with the post-CI T-level. Those with ASSRs at all frequencies had significantly lower CAP scores at the postoperative 1year. CI should not be delayed when marginal residual hearing is evident in ASSR.

일 도시 청년 인구의 불안 우울 공존 증상 네트워크 분석 (Network Analysis of Depressive and Anxiety Symptom in Young Adult of an Urban City)

  • 박종완;이효철;홍재은;이석범;이정재;김경민;정효석;김도현
    • 정신신체의학
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    • 제31권2호
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    • pp.118-124
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    • 2023
  • 연구목적 우울장애와 불안장애는 흔히 공존하며 임상전단계에서도 흔히 공존한다. 본 연구는 일반인구 집단에서 우울장애와 불안장애가 공존시의 복합 네트워크를 구성하여 중심 증상과 중개 증상을 밝히고자 했다. 방 법 2022년 아산시 청년 정신건강실태조사 데이터를 활용하여 진행하였다. 일반 인구집단 810명의 성인을 대상으로 PHQ-9과 GAD-7을 이용하여 각각 우울과 불안증상의 정도를 측정하였고, 각 증상에 대해 Isingfit model을 기반으로 네트워크 구조를 도출하였다. 주요 증상 및 중개 증상을 찾기 위해 네트워크 지표 중 강도 중심성과 bridge expected influence를 활용하였다. 결 과 우울한 기분, 안절부절 못함과 초조함이 네트워크에서 가장 높은 강도중심성을 보였으며, 불안증상과 우울증상 간의 높은 중개 역할을 하는 증상은 안절부절 못함과 과민성이었다. 결 론 일반 인구집단에서 우울증상과 불안증상이 공존할 때의 중심증 상과 중개증상을 규명하였고 치료적 중재의 목표가 되면 두 질환의 동반이환율을 감소시키는데 기여할 수 있을 것으로 기대된다.

Influences of luting cement shade on the color of various translucent monolithic zirconia and lithium disilicate ceramics for veneer restorations

  • Ghada Alrabeah;Nawaf Alamro;Atif Alghamdi;Ahmed Almslam;Meshari Azaaqi
    • The Journal of Advanced Prosthodontics
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    • 제15권5호
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    • pp.238-247
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    • 2023
  • PURPOSE. The purpose of this study was to assess the effect of resin cement shade on the color of different novel ultratranslucent monolithic zirconia and lithium disilicate veneer materials. MATERIALS AND METHODS. For a total of 40 specimens, flat cylindrical discs with a 9-mm diameter and 0.5-mm thickness were created using CAD/CAM technology. The specimens were divided into five groups according to their material (n = 8) (e.max, Prettau, Aidite, Shofu and Dima) using A1 shade. Resin discs with the same diameter and shade as the specimens served as tooth-colored substructures. Three shades (neutral, light and warm) of resin cement try-in pastes (Variolink Esthetic LC) were used as the luting cement material. The color of each material group was measured before and after cementation using the three cement shades, and the CIE L*a*b* coordinates were obtained with a spectrophotometer. Values for the translucency parameter (TP) and color change delta E (E) before (baseline) and after cementation of each specimen were determined. To compare differences among the material groups within each shade of cement and among various shades of cement within each material, the data were analyzed using one-way ANOVA and post hoc testing. RESULTS. Color coordinates L*, a* and b* significantly changed after the application of try-in pastes relative to baseline values, with a noticeable decrease in lightness (L*) (P < .05). A significant color change (ΔE) was observed in all tested materials after cementation, with ΔE values exceeding 3.3 (P < .05). Although TP changed after cementation for most materials tested, these changes were not statistically significant (P > .05). Shofu and Dima ceramics showed the lowest TP values, while Aidite and Prettau showed the highest TP values. For e.max, translucency decreased after cementation with neutral and warm shades, and it significantly increased after cementation with a light shade. CONCLUSION. The shade of cement significantly altered the final color of the ceramic veneer material to a level above the threshold at which the clinical perception of color change occurred (> 3.3). The TP was not influenced by the cement shade. The translucency levels of the novel ultratranslucent multilayer monolithic zirconia ceramics Aidite and Prettau were higher than that of the lithium disilicate e.max material.

유방 초음파 검사에서 석회화 유발 환경에 따른 반짝 허상과 팸텀을 활용한 영상 변화에 관한 연구 (A Study on the Image Change Using Twinkle Artifact Images and Phantom according to Calcification-Inducing Environment in Breast Ultrasonography)

  • 전철민
    • 한국방사선학회논문지
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    • 제17권5호
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    • pp.751-759
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    • 2023
  • 유방 초음파 검사는 지방형 유방에서 영상화가 어렵고 미세 석회화를 찾는 데 어려움이 있지만, 미세 석회화의 발견은 유방암 선별 검사에 매우 중요하다. 초음파의 컬러 도플러 허상 중 반짝 허상은 영상에서 주로 결석이나 석회화 같은 강한 반사체에 발생되며 이를 이용한 평가 방법이 임상적으로 사용 중이다. 본 연구는 유방 석회화 중 가장 많이 차지하는 인산칼슘을 이용한 유방 모의 팬텀을 제작하여 초음파 장비의 컬러 도플러 설정 변수인 펄스 반복 주파수, 앙상블, 퍼시스트, 월 필터, 평활화, 선밀도, 임계값에 대해 실험을 진행했고 이를 통해 유방 초음파 검사에서 반짝 허상의 대조도를 개선하는 조건과 임상에서 이를 최대한 활용하기 위한 방안을 연구하고자 하였다. 그 결과 펄스 반복 주파수가 3.6 kHz ~ 7.2 kHz 범위에서 반짝 허상이 발생하며 10.5 kHz 이상에서는 발생하지 않았다. 앙상블의 경우 낮은 조건에서는 모든 크기의 석회화에 반짝 허상이 발생하였고 임계값 설정에서는 80에서 100 조건에서만 반짝 허상이 조금 증가했으며 1 mm 크기의 석회화에서는 발생하지 않았다. 퍼시스트, 월 필터, 평활화, 선밀도 설정은 반짝 허상이 발생하긴 했으나 조건별로 증가하지는 않아 설정 변수에 큰 의미가 없었으며 반짝 허상에 가장 큰 영향을 미친 것은 펄스 반복 주파수, 앙상블, 임계값으로 나타났다. 본 연구는 검사자가 컬러 도플러 설정을 조절하여 반짝 허상을 효과적으로 증가시키는 최적의 조건을 선택하는 데 도움이 될 것으로 사료된다.

Effects of Contrast Phases on Automated Measurements of Muscle Quantity and Quality Using CT

  • Dong Wook Kim;Kyung Won Kim;Yousun Ko;Taeyong Park;Jeongjin Lee;Jung Bok Lee;Jiyeon Ha;Hyemin Ahn;Yu Sub Sung;Hong-Kyu Kim
    • Korean Journal of Radiology
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    • 제22권11호
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    • pp.1909-1917
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    • 2021
  • Objective: Muscle quantity and quality can be measured with an automated system on CT. However, the effects of contrast phases on the muscle measurements have not been established, which we aimed to investigate in this study. Materials and Methods: Muscle quantity was measured according to the skeletal muscle area (SMA) measured by a convolutional neural network-based automated system at the L3 level in 89 subjects undergoing multiphasic abdominal CT comprising unenhanced phase, arterial phase, portal venous phase (PVP), or delayed phase imaging. Muscle quality was analyzed using the mean muscle density and the muscle quality map, which comprises normal and low-attenuation muscle areas (NAMA and LAMA, respectively) based on the muscle attenuation threshold. The SMA, mean muscle density, NAMA, and LAMA were compared between PVP and other phases using paired t tests. Bland-Altman analysis was used to evaluate the inter-phase variability between PVP and other phases. Based on the cutoffs for low muscle quantity and quality, the counts of individuals who scored lower than the cutoff values were compared between PVP and other phases. Results: All indices showed significant differences between PVP and other phases (p < 0.001 for all). The SMA, mean muscle density, and NAMA increased during the later phases, whereas LAMA decreased during the later phases. Bland-Altman analysis showed that the mean differences between PVP and other phases ranged -2.1 to 0.3 cm2 for SMA, -12.0 to 2.6 cm2 for NAMA, and -2.2 to 9.9 cm2 for LAMA.The number of patients who were categorized as low muscle quantity did not significant differ between PVP and other phases (p ≥ 0.5), whereas the number of patients with low muscle quality significantly differed (p ≤ 0.002). Conclusion: SMA was less affected by the contrast phases. However, the muscle quality measurements changed with the contrast phases to greater extents and would require a standardization of the contrast phase for reliable measurement.

Accuracy of Digital Breast Tomosynthesis for Detecting Breast Cancer in the Diagnostic Setting: A Systematic Review and Meta-Analysis

  • Min Jung Ko;Dong A Park;Sung Hyun Kim;Eun Sook Ko;Kyung Hwan Shin;Woosung Lim;Beom Seok Kwak;Jung Min Chang
    • Korean Journal of Radiology
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    • 제22권8호
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    • pp.1240-1252
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    • 2021
  • Objective: To compare the accuracy for detecting breast cancer in the diagnostic setting between the use of digital breast tomosynthesis (DBT), defined as DBT alone or combined DBT and digital mammography (DM), and the use of DM alone through a systematic review and meta-analysis. Materials and Methods: Ovid-MEDLINE, Ovid-Embase, Cochrane Library and five Korean local databases were searched for articles published until March 25, 2020. We selected studies that reported diagnostic accuracy in women who were recalled after screening or symptomatic. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A bivariate random effects model was used to estimate pooled sensitivity and specificity. We compared the diagnostic accuracy between DBT and DM alone using meta-regression and subgroup analyses by modality of intervention, country, existence of calcifications, breast density, Breast Imaging Reporting and Data System category threshold, study design, protocol for participant sampling, sample size, reason for diagnostic examination, and number of readers who interpreted the studies. Results: Twenty studies (n = 44513) that compared DBT and DM alone were included. The pooled sensitivity and specificity were 0.90 (95% confidence interval [CI] 0.86-0.93) and 0.90 (95% CI 0.84-0.94), respectively, for DBT, which were higher than 0.76 (95% CI 0.68-0.83) and 0.83 (95% CI 0.73-0.89), respectively, for DM alone (p < 0.001). The area under the summary receiver operating characteristics curve was 0.95 (95% CI 0.93-0.97) for DBT and 0.86 (95% CI 0.82-0.88) for DM alone. The higher sensitivity and specificity of DBT than DM alone were consistently noted in most subgroup and meta-regression analyses. Conclusion: Use of DBT was more accurate than DM alone for the diagnosis of breast cancer. Women with clinical symptoms or abnormal screening findings could be more effectively evaluated for breast cancer using DBT, which has a superior diagnostic performance compared to DM alone.