• Title/Summary/Keyword: observational methods

검색결과 687건 처리시간 0.03초

Structure and Physical Conditions in MHD Jets from Young Stars

  • SHANG HSIEN
    • 천문학회지
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    • 제34권4호
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    • pp.297-299
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    • 2001
  • We have constructed the foundations to a series of theoretical diagnostic methods to probe the jet phenomenon in young stars as observed at various optical forbidden lines. We calculate and model in a self-consistent manner the physical and radiative processes which arise within an inner disk-wind driven magneto centrifugally from the circumstellar accretion disk of a young sun-like star. Comparing with real data taken at high angular resolution, our approach will provide the basis of systematic diagnostics for jets and their related young stellar objects, to attest the emission mechanisms of such phenomena. This work can help bring first-principle theoretical predictions to confront actual multi-wavelength observations, and will bridge the link between many very sophiscated numerical simulations and observational data. Analysis methods discussed here are immediately applicable to new high-resolution data obtained with HST and Adaptic Optics.

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고차원 관측자료에서의 Q-학습 모형에 대한 이중강건성 연구 (Doubly-robust Q-estimation in observational studies with high-dimensional covariates)

  • 이효빈;김예지;조형준;최상범
    • 응용통계연구
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    • 제34권3호
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    • pp.309-327
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    • 2021
  • 동적 치료 요법(dynamic treatment regimes; DTRs)은 다단계 무작위 시험에서 개인에 맞는 치료를 제공하도록 설계된 의사결정 규칙이다. 모든 개인이 동일한 유형의 치료를 처방받는 고전적인 방법과 달리 DTR은 시간이 지남에 따라 변할 수 있는 개별 특성을 고려한 환자 맞춤형 치료를 제공한다. 최적의 치료 규칙을 파악하기 위한 회귀 기반 알고리즘 중 하나인 Q-학습 방법은 쉽게 구현될 수 있기 때문에 더욱 인기를 끌고 있다. 그러나 Q-학습 알고리즘의 성능은 Q-함수를 제대로 설정했는지의 여부에 크게 의존한다. 본 논문에서는 고차원 데이터가 수집되는 DTRs 문제에 대한 다양한 이중강건 Q-학습 알고리즘을 연구하고 가중 최소제곱 추정 방법을 제안한다. 이중강건성(double-robustness)은 반응변수에 대한 모형 혹은 처리변수에 대한 모형 둘 중 하나만 제대로 설정되어도 불편추정량을 얻을 수 있음을 의미한다. 다양한 모의실험 연구를 통해 제안된 방법이 여러 시나리오 하에서도 잘 작동함을 확인하였으며 실제 데이터 예제를 통해 방법론에 대한 예시를 제시하였다.

신호교차로 안전성향상을 위한 단속카메라의 효과분석 연구 -측면직각 충돌사고를 중심으로- (Effect Analysis on Red Light Camera for Signalized Intersection Safety -Focused on Side Right-Angle Collision Accidents-)

  • 오주택;김용석;이용철
    • 한국도로학회논문집
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    • 제17권1호
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    • pp.119-127
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    • 2015
  • PURPOSES : Before-and-after studies of red light cameras were conducted with the aim of reducing the number of side right-angle collisions. Three different methods were used for the before-and-after studies, and the analysis results were compared. METHODS : This research used the naive before-and-after method, the comparison-group method, and the empirical Bayes method to study the effects of red light cameras on side-angle collisions. The results of the three before-and-after methods were compared and interpreted in terms of safety indications at signalized intersections. RESULTS : The research results showed that side right-angle collisions can be reduced by installing red light cameras at signalized intersections. All three methods guarantee safety improvements of 25~30% on average. With regard to the results of each method, the naive before-and-after method, the comparison-group method, and the empirical Bayes method showed safety improvements of 25.6%, 27.8%, and 29.7%, respectively. CONCLUSIONS : It was concluded that red light cameras are an effective countermeasure to improve intersection safety. In particular, by installing red light cameras, side right-angle collisions can be reduced by up to approximately 25~30%.

Quadrilateral Irregular Network for Mesh-Based Interpolation

  • Tae Beom Kim;Chihyung Lee
    • 지질공학
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    • 제33권3호
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    • pp.439-459
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    • 2023
  • Numerical analysis has been adopted in nearly all modern scientific and engineering fields due to the rapid and ongoing evolution of computational technology, with the number of grid or mesh points in a given data field also increasing. Some values must be extracted from large data fields to evaluate and supplement numerical analysis results and observational data, thereby highlighting the need for a fast and effective interpolation approach. The quadrilateral irregular network (QIN) proposed in this study is a fast and reliable interpolation method that is capable of sufficiently satisfying these demands. A comparative sensitivity analysis is first performed using known test functions to assess the accuracy and computational requirements of QIN relative to conventional interpolation methods. These same interpolation methods are then employed to produce simple numerical model results for a real-world comparison. Unlike conventional interpolation methods, QIN can obtain reliable results with a guaranteed degree of accuracy since there is no need to determine the optimal parameter values. Furthermore, QIN is a computationally efficient method compared with conventional interpolation methods that require the entire data space to be evaluated during interpolation, even if only a subset of the data space requires interpolation.

경추 추간판 탈출증 입원 환자 102례에 관한 한의학적 복합치료 효과의 관찰 연구 (Effects of Korean Medical Combination Treatment for 102 Cases of Cervical Disc Herniation : An Observational Study)

  • 최지훈;이순호;김상민;김현중;구자성;이현호;정성현;윤덕원
    • Journal of Acupuncture Research
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    • 제33권2호
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    • pp.11-20
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    • 2016
  • Objectives : The purpose of this study is to investigate the clinical effectiveness of Korean medical combination treatment for cervical disc herniation. Methods : This is an observational study. 102 patients diagnosed with cervical disc herniation by MRI (Magnetic Resonance Imaging) were investigated from January, 2015 through to December, 2015 at Daejeon Jaseng Hospital of Korean Medicine. They were sorted according to the distribution of sex, age, causing factor, the period of disease, admission day and pain area. All patients were treated with acupuncture, Chuna treatment, and herbal therapy and physical therapy during the admission period. After treatment, NRS (Numeric Rating Scale), NDI (Neck Disability Index) and EQ-5D were assessed to evaluate the treatment efficacy. Results : There were more females than Males with a ratio of 1 : 1.37, the age of fifty was the most with 35.29 %, reason unknown was the most with 72.55 % and the subacute stage was the most with 38.24 %. According to disc herniation types, patients with protruded disc types were the most with 66.67 % and a lesion of C5/6 was the most with 41.18 %. For patients diagnosed with cervical disc herniation, neck and shoulder pain NRS decreased from $6.43{\pm}1.77$ to $3.96{\pm}1.96$(p<0.001) and radiating pain NRS decreased from $5.64{\pm}1.96$ to $3.57{\pm}1.88$ (p<0.001). NDI decreased from $41.72{\pm}14.04$ to $30.84{\pm}15.34$(p<0.001), and the EQ-5D index increased from $0.68{\pm}0.17$ to $0.79{\pm}0.14$(p<0.001) after treating cervical disc patients. Conclusion : Korean medical combination treatment might be effective in decreasing pain and raising the life quality of patients with cervical disc herniation.

Protocol of a Nationwide Observational Study among Patients with Nontuberculous Mycobacterium Pulmonary Disease in South Korea (NTM-KOREA)

  • Kwak, Nakwon;Choi, Hongjo;Jeon, Doosoo;Jhun, Byung Woo;Jo, Kyung-Wook;Kang, Young Ae;Kwon, Yong-Soo;Lee, Myungsun;Mok, Jeongha;Shim, Tae-Sun;Shin, Hong-Joon;Whang, Jake;Yim, Jae-Joon
    • Tuberculosis and Respiratory Diseases
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    • 제83권2호
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    • pp.141-146
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    • 2020
  • Background: The burden of nontuberculous mycobacterial (NTM) pulmonary disease (PD) is increasing globally. To understand the treatment outcomes and prognosis of NTM-PD, a unified registry is needed. In this project, we aim to construct a multicenter prospective observational cohort with NTM-PD in South Korea (NTM-KOREA). Methods: The primary objective of this study is to analyze treatment outcomes according to the species. In addition, recurrence rate, adverse events, the impact of each drug on treatment outcomes as well as the impact of characteristics of mycobacteriology will be analyzed. The inclusion criteria for the study are as follows: fulfilling the criteria for NTM-PD having one of the following etiologic organisms: Mycobacterium avium complex, M. abscessus subspecies abscessus, M. abscessus subspecies massiliense, or M. kansasii; receiving the first treatment for NTM-PD after enrollment; age >20 years; and consenting to participate in the study. Seven institutions will participate in patient enrollment and about 500 patients are expected to be enrolled. Participants will be recruited from 1 March 2020 until 19 March 2024 and will be observed through 19 March 2029. During the follow-up period, participants' clinical course will be tracked and their clinical data as well as NTM isolates will be collected. Conclusion: NTM-KOREA will be the first nationwide observational cohort for NTM-PD in South Korea. It will provide the information to optimize treatment modalities and will contribute to deeper understanding of the treatment outcomes and long-term prognosis of patients with NTM-PD in South Korea.

요추 추간판탈출증 입원환자 72례에 대한 한의학적 복합치료 효과의 관찰 연구 (The Effect of Korean Medical Combination Treatment on 72 Cases of Herniated Intervertebral Lumbar Disc Patients: An Observational Study)

  • 김상민;이순호;신유빈;최지훈;구자성;유형진;이동현
    • Journal of Acupuncture Research
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    • 제32권2호
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    • pp.23-33
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    • 2015
  • Objectives : This study was designed to assess the general distribution and clinical effectiveness of Korean medical treatment on lumbar disc herniation. Methods : This is an observational study. 72 patients admitted to Daejeon Jaseng Hospital of Korean Medicine with a diagnosis of herniated intervertebral disc(HIVD) by lumbar-CT of lumbar-MRI were observed from July, 2014 to April, 2015. They were analyzed according to sex, age, the period of disease, causal factors, symptoms on admission, admission day, disc herniation type and treatment efficacy. All patients received a combination of treatments during hospitalization, including acupuncture, Chuna, herbal medicines and physical therapy. A zero to ten numerating rating scale(NRS) assessing pain, Oswestry disability index(ODI) and EuroQol-5 dimension(EQ-5D) was used before and after treatments. Results : Average admission duration was $28.00{\pm}12.85$ days in lumbar disc patients. For lumbar patients, lower back pain NRS decreased from $5.89{\pm}2.00$ to $3.42{\pm}1.87$(p<0.001) and radiating pain from $5.96{\pm}2.12$ to $3.38{\pm}1.83$(p<0.001). ODI decreased from $46.69{\pm}19.25$ to $35.69{\pm}16.67$(p<0.001), and EQ-5D index increased from $0.63{\pm}0.26$ to $0.71{\pm}0.20$(p<0.05) after treatment in lumbar disc patients. Conclusions : Korean medical combination treatment might be effective in reducing pain and improving quality of life for patients with lumbar disc herniation. This study further confirmed the efficacy of Korean medical treatment on HIVD.

한방병원에 입원한 화병 환자의 정서적 특성에 대한 핵심칠정척도 단축형을 활용한 후향적 관찰연구 (A Retrospective Observational Study on the Emotional Characteristics of Hwa-Byung Inpatients in a Korean Medicine Hospital Using the Core Seven-Emotions Inventory-Short Form)

  • 김주연;강동훈;강형원;정인철
    • 동의신경정신과학회지
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    • 제33권1호
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    • pp.1-19
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    • 2022
  • Objectives: The objective of this study was to confirm the Chiljeong (七情) characteristics of Hwa-byung patients using the core seven-emotions inventory-short form. Methods: We conducted a retrospective observational study based on the electronic medical records from a Korean medicine hospital. We included patients who were diagnosed with Hwa-byung and examined with Core Seven-Emotions Inventory-short Form (CSEI-S) during hospitalization periods. We presented the characteristics of Hwa-byung by demographic information, CSEI-S, Hwa-byung scale, and Korean Symptom Checklist 95. A correlation analysis was performed between CSEI-S and other clinical and psychological characteristics. Results: The Chiljeong characteristics of Hwa-byung were high in the order of Sorrow (悲), Thought (思), Fear (恐), Fright (驚), Depression (憂), Joy (喜), and Anger (怒). There was no significant difference between each emotion. After combined Korean medical treatment, Sorrow (悲) and Thought (思) significantly decreased. There were static correlations between sorrow (悲) and fright (驚), thought (思) and sorrow (悲), depression (憂) and sorrow (悲), depression (憂) and fright (驚), thought (思) and depression (憂), fear (恐) and fright (驚), anger (怒) and thought (思), thought (思) and fright (驚), sorrow (悲) and fear (恐). Sorrow (悲) and Hwa-byung characteristics scale showed static correlation. Joy (喜) showed a static correlation with disharmony between the heart and kidney scores of the Hwa-byung pattern identification. Between KSCL-95 and CSEI-S, static correlation appeared in depression (憂) with depression, anxiety, and sleep problem scale, sorrow (悲) with depression and anxiety, fright (驚) with depression and obsessive symptoms. Conclusions: Despite several limitations due to the study design and small sample size, this research successfully used CSEI-S to study the Chiljeong (七情) characteristics of Hwa-byung for the first time.

감로수(甘露水)를 이용한 절식요법의 임상결과에 관한 후향적 관찰연구 (Clinical Outcomes after Modified Fasting Therapy Supplied with Gamrosu: A Retrospective Observational Study)

  • 신승우;김동환;신현택;오달석
    • 한방비만학회지
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    • 제16권1호
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    • pp.36-49
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    • 2016
  • Objectives: Two historical evidence supported the concept of Gamrosu. The first one was Jeho-tang, a selected thirst quencher in Chosun Dynasty and the second one was Saeng-Maek-san, Dongeuibogam's recommendation as one of the qi-vigorating summer beverages. Gamrosu is a modified fasting therapy beverage which is manufactured from those two prescriptions and the carbohydrates (420.6 kcal/d). A retrospective observational study was conducted to evaluate the clinical outcomes. Methods: Thirty-three cases were reviewed at three local Korean Medical clinics that each site's participant has finished the modified fasting for 10 consecutive days. Clinical outcomes were reviewed at pre- and post-fasting sessions by retrieving the changes of body composition, blood pressure, blood chemistries & urine tests, and subjective symptoms & fatigue scores. Results: Demographics of the observed participants were 17 of male and 16 of female. Post-Gamrosu session, -6.89% of body weight, -8.97% of body fat mass were reduced with the nutrition indices being improved (P<0.001). -8.72% of systolic blood pressure, -39.86% of serum triglyceride, -6.75% of fast blood sugar and -8.12% of waist circumference were improved (P<0.05). The levels of high sensitivity C-reactive protein (-58.34%), CRP (-43.55%) and eosinophil (-21.30%) showed the significant diminished profiles (P<0.05). Liver/kidney functions and the standard of electrolytes were maintained within normal range in stable manners. The fatigue scale scores indicated significant lower scores. Conclusions: Taken together, obesity-related clinical outcomes after a modified fasting therapy with Gamrosu were sufficiently feasible and the observed findings should be considered for further prospective clinical studies.

Diabetes Mellitus Increases the Risk of Bladder Cancer: An Updated Meta-analysis

  • Yang, Xiao-Qing;Xu, Chen;Sun, Yan;Han, Rui-Fa
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권4호
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    • pp.2583-2589
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    • 2013
  • Purpose: Studies have indicated that diabetes mellitus (DM) is a risk factor for bladder cancer; however, not all evidence supports this conclusion. The aim of this meta-analysis was to collate and evaluate all primary observational studies investigating the risk of bladder cancer associated with DM. Methods: The PubMed and Google Scholar databases were searched to identify studies that estimated the association of DM and bladder cancer. Summary effect estimates were derived using a random-effects meta-analysis model. Results: A total of 23 studies (8 case-control studies, 15 cohort studies) including 643,683 DM and 4,819,656 non-DM cases were identified. Analysis of all studies showed that DM was associated with an increased risk of bladder cancer compared with non-DM overall (OR=1.68, 95% CI 1.32-2.13). Analysis of subgroups demonstrated this to be the case in both case-control studies (OR=1.59, 95% CI 1.28-1.97, $I^2$=58%) and cohort studies (RR=1.70, 95% CI 1.23-2.33, $I^2$=96%). There was no gender difference in DM-associated bladder cancer risk. Bladder cancer risk was increased in Asia and the North America region, but not in Europe. Furthermore, DM-associated bladder cancer risk was obviously higher in Asia than North America and Europe or in those with Caucasian ethnicity. With extension of follow-up time, the bladder cancer risk was not increased for the patients with DM. Conclusions: This meta-analysis provided further evidence supporting theDM association with a significantly higher risk of bladder cancer obtained from observational studies.