• 제목/요약/키워드: Local Regression Rate

검색결과 203건 처리시간 0.023초

입구 와류발생과 질량분사가 있는 연소실 내부유동의 LES 해석 (LES for Turbulent Duct Flow with Surface Mass Injection and Vortex Shedding)

  • 몬킨우;구희석;이창진
    • 한국항공우주학회지
    • /
    • 제40권9호
    • /
    • pp.745-751
    • /
    • 2012
  • 하이브리드 로켓은 축 방향의 산화제 유동과 고체 연료의 기화로 인한 벽면 분출 유동사이의 상호 간섭에 의해 복잡한 형태의 혼합 전단층이 존재한다. 연소실 입구에 링이 설치되어 있고 질량분사가 있는 실린더 유동에 대하여 압축성 효과를 고려한 LES(Large Eddy Simulation) 기법을 적용하여 수치계산을 수행하였다. 최근의 실험에 의하면 연료 중간에 링과 같은 다이아프램이 설치된 경우, 연소율의 증가가 관찰되었다. 계산 결과에 따르면, 축방향 유동과 벽면 분출 유동이 상호 간섭하여 발생하는 벽면 와류가 국부적인 연료 표면으로의 열전달을 증가시켜 실험에서 관찰되는 딤플이 생성되는 것을 확인하였다. 또한 연소실 입구에 설치된 링에 의하여 발생되는 와류는 벽면 와류가 보다 활발하게 생성되고 열전달과 혼합을 향상시키는 역할을 하며 이 때문에 연소율이 증가되는 것으로 보인다.

Risk factors of delayed diagnosis of acute appendicitis in children: for early detection of acute appendicitis

  • Choi, Jea Yeon;Ryoo, Eell;Jo, Jeong Hyun;Hann, Tchah;Kim, Seong Min
    • Clinical and Experimental Pediatrics
    • /
    • 제59권9호
    • /
    • pp.368-373
    • /
    • 2016
  • Purpose: This study examined the risk factors of a delayed diagnosis of acute appendicitis in children undergoing an appendectomy. Methods: This retrospective study involved children aged below 18 years, who underwent an appendectomy. After dividing them into a delayed diagnosis group and nondelayed diagnosis group according to the time interval between the initial hospital visit and final diagnosis, the risk factors of delayed diagnosis were identified using logistic regression analysis. Results: Among 712 patients, 105 patients (14.7%) were classified in the delayed diagnosis group; 92 patients (12.9%) were diagnosed using ultrasonography (US), and both US and computed tomography were performed in 38 patients (5.3%). More patients in the delayed diagnosis group underwent US (P=0.03). Spring season and prior local clinic visit were significantly associated with a delayed diagnosis. Fever and diarrhea were more common in the delayed diagnosis group (fever: odds ratio [OR], 1.37; 95% confidence interval [CI], 1.05-1.81; diarrhea: OR, 1.94; 95% CI, 1.08-3.46; P<0.05). These patients showed symptoms for a longer duration (OR, 2.59; 95% CI, 1.78-3.78; P<0.05), and the admission course (OR, 1.26; 95% CI, 1.11-1.44; P<0.05) and C-reactive protein (CRP) levels (OR, 1.47; 95% CI, 1.19-1.82; P<0.05) were associated with the delayed diagnosis. Conclusion: To decrease the rate of delayed diagnoses of acute appendicitis, symptoms such as fever and diarrhea, seasonal variations, admission course, and CRP levels should be considered and children with a longer duration of symptoms should be closely monitored.

Antibiotic use in nasal bone fracture: a nationwide population-based cohort study in Korea

  • Jeon, Yeo Reum;Jung, Ji Hyuk;Song, Joon Ho;Chung, Seum
    • 대한두개안면성형외과학회지
    • /
    • 제22권5호
    • /
    • pp.254-259
    • /
    • 2021
  • Background: Prophylactic antibiotics are commonly used in craniofacial surgeries. Despite the low risk of surgical site infection after nasal surgery, a lack of consensus regarding the use of antibiotic prophylaxis in the closed reduction of nasal bone fractures has led to inappropriate prescribing patterns. Through this study, we aimed to investigate the status of prophylactic antibiotic use in closed reductions of nasal bone fractures in Korea. Methods: This retrospective cohort study was conducted using data from the National Health Insurance Service-National Sample Cohort of Korea from 2005 to 2015. We analyzed the medical records of patients who underwent closed reduction of nasal bone fractures. The sex, age, region of residence, comorbidities, and socioeconomic variables of the patients were collected from the database. Factors that affect the prescription of perioperative antibiotics were evaluated using multivariate logistic regression analysis. Results: A total of 3,678 patients (mean±standard deviation of age, 28.7±14.9 years; 2,850 men [77.5%]; 828 women [22.5%]) were included in this study. The rate of antibiotic prescription during the perioperative period was 51.4%. Approximately 68.8% of prescriptions were written for patients who had received general anesthesia. The odds of perioperative prophylactic antibiotic use were significantly higher in patients who received general anesthesia than who received local anesthesia (odds ratio, 1.59). No difference was found in terms of patient age and physician specialty. Second-generation cephalosporins were the most commonly prescribed antibiotic (45.3%), followed by third- and first-generation cephalosporins (20.3% and 18.8%, respectively). In contrast, lincomycin derivatives and aminoglycosides were not prescribed. Conclusion: The findings of this study showed that there was a wide variety of perioperative antibiotic prescription patterns used in nasal bone surgeries. Evidence-based guidance regarding the prescribing of antimicrobial agents for the closed reduction of nasal bone fractures should be considered in future research.

P파를 이용한 지진 현장 경보체계기술의 국내 적용 (Application of the Onsite Earthquake Early Warning Technology Using the Seismic P-Wave in Korea)

  • 이호준;이진구;전인찬
    • 한국재난정보학회 논문집
    • /
    • 제14권4호
    • /
    • pp.440-449
    • /
    • 2018
  • 연구목적: 본 연구는 단일 지진관측기로부터 P파를 추출하여 PGV를 산출하는 현장지진경보(Onsite EEW)를 설계와 검증을 목적으로 한다. 연구방법: 국내에서 발생한 12개의 지진파형데이터를 이용하여 적합한 P파 감지 시간(PTW)의 크기를 정하여, P파 물성치인 Pd, Pv 및 Pa를 산출하고, 경험식을 통한 PGV 추정값을 관측치와 비교하였다. 연구결과: PGV 관측치와 추정치의 비교결과를 경보 발령 기준인 진도 등급 내에서 비교하였을 때 오보 비율은 최소 86.7%의 적중률을 보였으며, PTW를 2초로 줄이는 효과로 경보시간은 1초, 공백역은 6Km를 단축할 수 있다. 결론: 본 연구를 통해 국내에서 지진현장경보의 가용성을 확인하였으며, 실제 활용을 위해서는 지속적인 관측을 통해 지진파형 데이터수를 늘이고, 현장 노이즈를 제거하는 기술을 통해 한국형의 회귀식과 알고리즘 개발이 필요하다.

300인 미만 사업장근로자의 6개월 이내 재흡연 관련요인 (Factors Related to Smoking Recurrence within Six-months Smoking Cessation among Employees in Enterprises with Smaller than 300 Workers)

  • 진병준;김철웅;이승은;임효빈;이태용
    • 지역사회간호학회지
    • /
    • 제32권1호
    • /
    • pp.107-115
    • /
    • 2021
  • Purpose: The purpose of this study is to identify factors associated with smoking relapse within six months after quit attempts among workers in small and medium-sized enterprises in South Korea. Methods: The analysis was conducted for a total of 194 people who attempted to quit smoking by applying for a smoking cessation support service at the Regional Tobacco Control Center. The data used in the study were extracted from the Smoking Cessation Service Integrated Information System. Kaplan-Meier estimator and Cox proportional hazards regression model were used to identify variables associated with smoking relapse within six months' time period. Results: Smoking relapse rate within six months was 66.0%, and variables associated with relapse included the cases such as carbon monoxide (CO) at the time of registration (HR: 2.15, 95% CI: 1.10~4.22 for CO ≥20 ppm or more vs.CO <10 ppm), the average number of cigarettes smoked per day (HR: 1.04, 95% CI: 1.00~1.07), and the number of counseling(HR: 0.60, 95% CI: 0.54~0.67). Conclusion: Smoking characteristics and counseling showed one of the strongest correlations with relapse within six months. This implies that it is necessary to understand the smoking characteristics and patterns of workers and to provide continuous smoking cessation counseling tailored to individual characteristics for effective smoking relapse prevention.

사회생태학적 모형에 의한 건강 생활 실천 관련 요인 (Factors Influencing Healthy Living Practice by Socio-ecological Model)

  • 김윤정;박정하
    • 문화기술의 융합
    • /
    • 제7권4호
    • /
    • pp.351-361
    • /
    • 2021
  • 본 연구의 목적은 건강한 생활습관에 영향을 미치는 요인을 규명하여 개인 및 지역의 건강불평등을 해소하기 위한 기초자료를 제공하고, 건강형평성 접근과 국민의 건강권을 보호하는데 있다. 2019 지역사회건강조사자료를 사용하였고, SAS 9.4와 IBM SPSS를 이용하여 기술통계분석과 다변량 로지스틱 회귀분석을 수행하였다. 건강한 생활실천율은 전체의 33.8%로 지역별로 11~20%의 차이가 있었다. 개인요인으로는 성별, 연령, 직업, 수면시간, 주관적 건강상태, 주관적 스트레스 정도에서 건강한 생활습관이 유의한 차이를 보였다. 개인 간 관계 요인에서는 건강한 생활실천을 위한 사회활동에 차이가 있었고, 지역사회 요인에서는 지역의 물리적 환경에 대한 긍정적인 태도, 연간 의료불만족, 의료기관 이용에 유의한 차이가 있었다. 향후 지역별 건강한 삶의 실천을 확대하기 위해서 구체적인 전략과 함께 개인, 사회, 국가 차원에서 접근할 수 있는 종합적인 정책과 협력방안을 추진해야 할 것이다.

중증질환자의 민간의료보험 가입 현황 및 관련요인 (Status and related factors of private health insurance for severely ill patients)

  • 김석환
    • 한국산학기술학회논문지
    • /
    • 제19권1호
    • /
    • pp.497-505
    • /
    • 2018
  • 이 연구의 목적은 중증질환자들을 대상으로 민간의료보험 가입자와 미가입자간의 특성을 파악하고, 가입 요인을 분석하기 위함이다. 연구도구는 2015년도 국민건강영양조사 자료를 이용하였으며, SPSS ver 23.0을 사용하였고, 연구 대상자는 19세 이상 중증질환자(암, 심장질환, 뇌혈관질환) 417명을 선정하였다. 분석방법은 민간의료보험 가입 현황과 차이를 파악하기 위해 교차분석을 실시하였고, 민간의료보험 가입에 미치는 요인을 분석하기 위해 이항 로지스틱 회귀분석을 실시하였다. 분석 결과 사회 인구학적 특성에서는 성별, 거주지, 혼인상태와 관계없이 나이가 젊을수록 높았다. 그리고, 사회 경제적 상태에서는 교육수준과 관계없이 가구소득이 높을수록, 의료급여대상자에 비하여 건강보험대상자의 가입률이 높았다. 건강행태에서는 주관적 건강 인식 및 걷기 실천과 무관하게 활동제한이 있는 집단의 민간의료보험 가입률이 낮았으며, 설명력은 51.7%이었다. 그러므로, 중증질환자 중 민간의료보험에 가입하지 못한 집단을 선별하여 생활환경 개선 및 지방자치단체의 지원을 촉구해야 할 것이다. 또한, 사회적 취약계층 및 건강행태에 제한 있는 집단을 대상으로 중증질환 예방을 위한 정부의 보건교육 또는 프로그램 제공 등 다양한 보건정책을 고려해야 할 것이다.

요통환자들의 성생활 행태와 영향 요인 조사 (A survey on sex life behavior and factors of low back pain)

  • 남철현;우광석
    • 대한물리치료과학회지
    • /
    • 제9권3호
    • /
    • pp.31-49
    • /
    • 2002
  • The purpose of this study was to investigate discomforts and sexual life and to identify the relation between the discomforts and sexual life with low back pain. The data were collected from March 2 through July 31, 2001. Four hundred forty-two questionnaires were returned (response rate=88.0%). Analysis of the data was done with SPSS PC+ and use descriptive statistics, $x^2$-test, t-test, ANOVA. regression. The statistics shows that over than 80% of the adults experienced lumbago at least one time in their life, and Back pain is known as one of the most common complaints made by the patients of all ages in the general hospital or local medical clinics throughout. However, in certain case it leads to a chronic condition which can cause a great deal of problems in management and in financial burden to individuals and society. The result of this study was summarized as follows: 1) It appeared that regarding the distribution of gender, male was the higher(63.6%) then that of female, the portion of forties was 28.5%. Sitting for long time was 23.1% in men and 21.7% in women. Unknown reason including sexual behaviour was 12.9% in men and 15.5% in women. Patients treated medicine and physical therapy were 36.4%. In level of educational background, the rate of high school was 31.0%, technical college was 28.5%. The highest proportion by occupation was 18.3% of office workers, occupation posture was 41.9% of sitting. 2) Men(26.0%) and most of women(34.8%) were not satisfied in the explanation satisfaction rate of sex life concerned disease. 23.8% in men and 23.6% in women considered flexibility of waist good. Man(33.3%) and most of woman(35.0%) considered that Health education is necessary. 32.7% in men and 27.3% in women did't mind educator is whoever. Preventing of lower back pain(LBP) and proper Health education of sex life are demanded in daily life. 3) 58.0% of man and 64.0% of woman mostly had a posture which is man over woman. 28.5% in men and 27.8% in women considered that proper information finding of LBP and sex life was very few and few. 37.7% in men and 42.7% in women have acquired information about sex life flung their friends. 4) The number of sex life was decreased from 2.96 0.98 to 2.61 1.63 and also the time of sex life was decreased from 3.65 1.89 to 226 1.64. The satisfaction rate of sex life changed from 3.60 0.86 to 2.77 1.10. In the number of sex life, The non correct group was 2.62 1.91 and the correct group was higher in 2.68 1.65. In the time of sex life, The non correct group was 2.02 1.47 and the correct group was higher in 229 1.65. The satisfaction rate of sex life was 2.76 0.86 in non correct group and 2.88 1.10 in correct group. So there was a difference. 5) In the satisfaction rate of sex life, Men who have a lower back pain were higher than women and no attack group was higher than attack group. As they had many sex life, the satisfaction rate was higher significantly in statistics. As the time of sex life was short, the satisfaction rate was lower significantly in statistics. As the age was low, the demand rate of Health education was high and as means of patient who had a lower back pain was high, the demand rate of Health education was high. As the patient who had a lower back pain had a long married life, the demand rate of Health education was high and as education level was high, the demand rate of Health education was high. It is necessary to provide patients with conservative treatment, educational teaching, and training to prevent further injuries in the future. In general, it is important to educate the public how to prevent back injuries and how to treat themselves in an onset period to prevent further injuries sliding into a chronic state. Sexuality is an integral part of normal and healthy relationships, but patients are unable to enjoy sex because they are riot able to get into a comfortable position due to back pain. Many conditions of the spine can make certain positions uncomfortable. Health educator should make the education program of the discomforts and the sexual pattern for low back pain in workplace and/or hospital. Further study Is needed on how to integrate the educational program on sexuality into the total rehabilitation program.

  • PDF

Breast Screening and Breast Cancer Survival in Aboriginal and Torres Strait Islander Women of Australia

  • Roder, David;Webster, Fleur;Zorbas, Helen;Sinclair, Sue
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제13권1호
    • /
    • pp.147-155
    • /
    • 2012
  • Aboriginal and Torres Strait Islander people comprise about 2.5% of the Australian population. Cancer registry data indicate that their breast cancer survivals are lower than for other women but the completeness and accuracy of Indigenous descriptors on registries are uncertain. We followed women receiving mammography screening in BreastScreen to determine differences in screening experiences and survivals from breast cancer by Aboriginal and Torres Strait Islander status, as recorded by BreastScreen. This status is self-reported and used in BreastScreen accreditation, and is considered to be more accurate. The study included breast cancers diagnosed during the period of screening and after leaving the screening program. Design: Least square regression models were used to compare screening experiences and outcomes adjusted for age, geographic remoteness, socio-economic disadvantage, screening period and round during 1996-2005. Survival of breast cancer patients from all causes and from breast cancer specifically was compared for the 1991-2006 diagnostic period using linked cancer-registry data. Cox proportional hazards regression was used to adjust for socio-demographic differences, screening period, and where available, tumour size, nodal status and proximity of diagnosis to time of screen. Results: After adjustment for socio-demographic differences and screening period, Aboriginal and Torres Strait Islander women participated less frequently than other women in screening and re-screening although this difference appeared to be diminishing; were less likely to attend post-screening assessment within the recommended 28 days if recalled for assessment; had an elevated ductal carcinoma in situ but not invasive cancer detection rate; had larger breast cancers; and were more likely than other women to be treated by mastectomy than complete local excision. Linked cancer registry data indicated that five-year year survivals of breast cancer cases from all causes of death were 81% for Aboriginal and Torres Strait Islander women, compared with 90% for other women, and that the former had larger breast cancers that were more likely to have nodal spread at diagnosis. After adjusting for socio-demographic factors, tumour size, nodal spread and time from last screen to diagnosis, Aboriginal and Torres Strait Islander women had approximately twice the risk of death from breast cancer as other women. Conclusions: Aboriginal and Torres Strait Islander women have less favourable screening experiences and those diagnosed with breast cancer (either during the screening period or after leaving the screening program) have lower survivals that persist after adjustment for socio-demographic differences, tumour size and nodal status.

폐석면광산 주변 지역의 주택 침적먼지의 석면 검출과 석면폐증의 관련성 (Exposure Assessment and Asbestosis Pulmonum among Inhabitants near Abandoned Asbestos Mines Using Deposited Dust)

  • 안호기;양원호;황보영;이용진
    • 한국환경보건학회지
    • /
    • 제41권6호
    • /
    • pp.369-379
    • /
    • 2015
  • Objectives: The lack of reliable information on environmental pollution and health impacts related to asbestos contamination from abandoned mines has drawn attention to the need for a community health study. This study was performed to evaluate asbestos-related health symptoms among residents near abandoned asbestos mines located in the Chungcheong Provinces. In addition, exposure assessment for asbestos is needed although the exposure to asbestos was in the past. Methods: Past exposure to asbestos among inhabitants near abandoned asbestos mines was estimated by using surface sampling of deposited dust in indoor and outdoor residences. A total of 54 participants were divided into two groups with (34 cases) and without (20 controls) diseases related to asbestos. Surface sampling of deposited dust was carried out in indoor and outdoor residences by collecting 105 samples. Deposited dust for sampling was analyzed by polarization microscope (PLM) and scanning electron microscope?energy dispersive x-ray spectrometer (SEM-EDX) to detect asbestos. Subsequently, the elements of the deposited dust with asbestos were analyzed by SEM-EDX to assess the contribution of sources such as abandoned mines, slate and soil. Results: Among the 105 samples, asbestos was detected by PLM in 29 (27.6%) sampling points, and detected by SEM in 56 (48.6%) sampling points. Asbestos in indoor residences was detected by PLM in four sampling points, and by SEM in 12 sampling points. Asbestos detection in indoor residences may be due to ventilation between indoors and outdoors, and indicates long-term exposure. The asbestos detection rate for outdoor residences in the case group was higher than that in the control group. This can be explained as the case group having had higher exposure to asbestos, and there has been continuous exposure to asbestos in the control group as well as the case group. Conclusion: Past residential asbestos exposure may be associated with asbestosis among local residents near abandoned asbestos mines. Odds ratios were calculated for asbestos detection in outdoor residence by logistic regression analysis. Odds ratio between asbestos detection and asbestosis pulmonum was 3.36 (95% CI 0.90-12.53) (p=0.072), adjusting for age, sex, smoking status and work history with multi-variable logistic regression by PLM analysis method.