• 제목/요약/키워드: randomized response model

검색결과 52건 처리시간 0.023초

로컬 차분 프라이버시 실제 적용 사례연구 : 프라이버시 보존형 설문조사 (Case Study on Local Differential Privacy in Practice : Privacy Preserving Survey)

  • 정수용;홍도원;서창호
    • 정보보호학회논문지
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    • 제30권1호
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    • pp.141-156
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    • 2020
  • 차분 프라이버시는 데이터 프라이버시를 보존함과 동시에 데이터를 수집 및 분석할 수 있는 기법으로써 프라이버시 보존형 데이터 활용 분야에서 널리 적용되고 있다. 이러한 차분 프라이버시의 지역적 모델인 로컬 차분 프라이버시 알고리즘은 무작위 응답을 기반으로 데이터 소유자가 직접 데이터를 가공 처리하여 공개한다. 따라서 개인은 데이터 프라이버시를 보장받을 수 있으며, 데이터 분석가는 수집된 다수의 데이터를 통해 유용한 통계적 결과값을 도출할 수 있다. 이러한 로컬 차분 프라이버시 기법은 세계적 기업인 Google, Apple, Microsoft에서 실질적으로 사용자의 데이터를 수집 및 분석할 때 활용되고 있다. 본 논문에서는 현실에 실질적으로 활용되고 있는 로컬 차분 프라이버시 기법에 대해 비교분석한다. 또한, 실제 적용 사례 연구로써 개인의 프라이버시가 결과의 신뢰성에 큰 영향을 미치는 설문 및 여론조사 시나리오를 기반으로 로컬 차분 프라이버시 기법을 적용하여 현실에서의 활용 가능성에 대해 연구한다.

Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Versus Placebo as Maintenance Therapy for Advanced Non-small-cell Lung Cancer: A Meta-analysis of Randomized Controlled Trials

  • Alimujiang, S.;Zhang, Tao;Han, Zhi-Gang;Yuan, Shuai-Fei;Wang, Qiang;Yu, Ting-Ting;Shan, Li
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권4호
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    • pp.2413-2419
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    • 2013
  • Background: Use of epidermal growth factor receptor inhibitors (EGFR-TKIs ) is now standard for non-small-cell lung cancer (NSCLC). However, the effects of EGFR-TKIs in maintenance therapy for advanced NSCLC patients are still unclear. The preent meta-analysis was performed to examine pooled data of randomized control trials (RCT) where EGFR-TKIs were compared against placebo in maintenance regimens for patients with advanced NCSLC to quantify potential benefits and determine safety. Methods: Several data bases were searched, including PubMed, EMBASE and CENTRAL, and we performed an internet search of conference literature. The endpoints were objective response rates (ORR), progression-free survival (PFS) and overall survival (OS). We performed a meta-analysis of the published data, using Comprehensive Meta Analysis software (Version 2.0). with a fixed effects model and an additional random effects model, when applicable. The results of the meta-analysis are expressed as hazard ratios (HRs) or risk ratios (RRs), with their corresponding 95% confidence intervals (95%CIs). Results: The final analysis included six trials, covering 3,758 patients. Compared with placebo, EGFR-TKIs maintenance therapy improved ORR and PFS for patients with advanced NSCLC, the difference being statistically significant (P<0.05), but proved unable to prolong patients' OS. The main adverse reactions were diarrhea and rashes. Conclusion: EGFR-TKIs demonstrated encouraging efficacy, safety and survival when delivered as maintenance therapy for patients with advanced NSCLC after first-line chemotherapy, especially for the patients who had adenocarcinomas, were female, non-smokers and patients with EGFR gene mutations.

층화 및 층화 이표본 조건부 무관질문모형 (A Stratified and Two Sample Stratified Conditional Unrelated Question Model)

  • 이기성
    • Journal of the Korean Data Analysis Society
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    • 제20권6호
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    • pp.2883-2893
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    • 2018
  • 본 논문에서는 모집단이 층으로 구성되어 있고 얻고자 하는 속성이 민감할 때, 덜 민감한 속성 B와 강요응답으로 구성되어 있는 확률장치를 통해 "예"라고 응답한 사람들에게만 민감한 속성 A 와 무관한 속성 Y를 포함하고 있는 Greenberg et al.(1969)의 무관질문모형을 사용하도록 하여 모집단이 층화된 경우 층화추정을 위한 층화 조건부 무관질문모형을 제안하였다. 그리고 제안한 층화 조건부 무관질문모형에서 각 층에 표본을 배분할 때 비례배분과 최적배분 문제를 다루었다. 또한 층화 조건부 무관질문모형을 무관한 속성이 미지인 경우 두 개의 독립표본을 이용하는 층화 이표본 조건부 무관질문모형으로 확장하였으며, 제안한 층화 이표본 조건부 무관질문모형의 두 번째 단계에서 사용되는 h층의 표본의 크기에 대한 최적값을 도출하여 최소분산을 구하였다. 마지막으로 층화 조건부 무관질문모형이 층화 무관질문모형과 층화 Carr et al.(1982)의 모형보다 효율적이 되는 조건을 제시하여 일정한 조건하에서 제안한 모형이 기존 모형들보다 효율적임을 보였으며, 제안한 층화 조건부 무관질문모형이 ${\pi}_{h2}$ 값이 작고 ${\pi}_{hy}$ 값이 작을수록 층화 Carr et al.(1982)의 모형보다 효율적임을 수치적으로 보였다.

뉴로피드백 훈련이 후기청소년의 신체적, 정서심리적 스트레스 반응과 자기조절에 미치는 효과: 비무작위 연구 (The Effects of Neurofeedback Training on Physical, Psychoemotional Stress Response and Self-Regulation for Late Adolescence: A Non-Randomized Trial)

  • 최문지;박완주
    • 대한간호학회지
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    • 제48권2호
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    • pp.208-220
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    • 2018
  • Purpose: The aim of this study was to analyze the effects of neurofeedback training for reducing stress and enhancing self-regulation in late adolescence to identify the possibility of use for nursing intervention. Methods: A nonequivalent control group pre-post quasi-experimental design was used. Participants were 78 late adolescents assigned to the experimental group (n=39) that received the neurofeedback training and the control group (n=39). Data were collected on heart rate variability (HRV) and skin conductance level (SCL) to assess stress-biomarker response. The questionnaire contained 164 items from: Positive and Negative Affect Schedule (PANAS), Symptom Checklist-90-Revised (SCL-90-R) and Self-regulatory Ability scale. The neurofeedback training was based on the general adaptation syndrome and body-mind medicine. The intervention was conducted in a total of 10 sessions for 30 minutes per session with high-beta, theta and sensory motor rhythm training on scalp at central zero. Results: There were significant difference in standard deviation of normal to normal interval (p=.036) in HRV and SCL (p=.029) of stress-biomarker response between the two groups. Negative affect (p=.036) in PANAS and obsessive compulsive (p=.023) and depression (p<.001) in SCL-90-R were statistically significant. Self-regulation mode (p=.004) in self-regulation ability scale showed a significant difference between the two groups. Conclusion: The results indicated that the neurofeedback training is effective in stress-biomarkers, psychoemotional stress response and self-regulation. Therefore, neurofeedback training using neuroscientific approach based on brain-mind-body model can be used as an effective nursing intervention for late adolescents in clinics and communities for effective stress responses.

Correlation of Tumour Response with Starting Tumour Size and Dose of Tamoxifen in an N-Methyl-N-Nitrosourea (NMU)-Induced Rat Mammary Cancer Model

  • Yankuzo, Hassan Muhammad;Emilia, Sharifah Tuan Sheriff;Shaari, Rumaizi;Yaacob, Nik Soriani
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권16호
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    • pp.6721-6726
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    • 2014
  • Background: The aim of this preliminary study was to address variations of responses observed with different starting tumor sizes of 10 and 15 mm, and the effects of different doses of tamoxifen (TAM) on experimental rat mammary tumors. Materials and Methods: Thirty-five inbred female Sprague Dawley rats aged 43 days were administered with three weekly doses of N-methyl-N-nitrosourea (NMU) intraperitoneally (ip) at 50 mg/kg body weight. Animals were randomized (beginning from 10 mm tumor size) into four TAM-treated (50, 100, 200 and $500{\mu}g/day$) groups of six animals each, and another group (n=6) treated with TAM $100{\mu}g/day$ at starting tumour size of 15 mm. The animals were treated by oral gavage daily for 8 weeks before sacrifice. Results: Serum urea and creatinine, and overall physical tumor burden were significantly modulated in animals treated with variable doses of TAM compared to the untreated controls (n=5). Final body weight and tumor number were significantly different in the 10 mm-treated animals compared to those treated at 15 mm. There were no significant differences in histopathological features among all the groups. Conclusions: Our findings suggest the importance of standardizing tumour size and drug doses before initiation of treatment, particularly in the direct comparison of basic end-tumour physical parameters.

Proline, Sugars, and Antioxidant Enzymes Respond to Drought Stress in the Leaves of Strawberry Plants

  • Sun, Cunhua;Li, Xuehua;Hu, Yulong;Zhao, Pingyi;Xu, Tian;Sun, Jian;Gao, Xiali
    • 원예과학기술지
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    • 제33권5호
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    • pp.625-632
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    • 2015
  • Drought is a severe abiotic stress that affects global crop production. A drought model was created for 'Toyonoka' Fragaria ${\times}$ ananassa, and the effects of drought stress on contents of proline, sugars, and antioxidant enzyme activities were investigated. Strawberry transplants with identical growth were chosen for the experiments and the randomized design included four replications (10 plants per block). The experimental sets differed in the moisture level of the culture medium relative to the range of moisture content as follows: control, 70-85%; mild drought stress, 50-60%; moderate drought stress, 40-50%; and severe drought stress, 30-40%. Drought stress was imposed by limiting irrigation. Plants were sampled and physiological parameters w ere measured on 0, 2, 4, 6, 8, and 10 days after the commencement of droughts tress. The water potential of strawberry leaves decreased in the plants under mild, moderate, and severe stress during the course of the water stress treatment and exhibited a significant difference from the control. Strawberry leaves subjected to drought stress had higher accumulation of proline, sugars, and malondialdehyde, and higher activities of superoxide dismutase, peroxidase, and catalase than leaves of control plants. Malondialdehyde levels increased in parallel with the severity and duration of drought stress. By contrast, antioxidant enzyme activity displayed dynamic responses to drought stress, first increasing and subsequently decreasing as the severity and duration of drought stress increased. These results suggest that strawberry plants respond to drought stress by altering the activities of antioxidant enzymes and the levels of osmotically active metabolites. These biochemical response changes may confer adaptation to drought stress and improve the capacity of plants to withstand water-deficit conditions.

Dose-dependent effects of a microbial phytase on phosphorus digestibility of common feedstuffs in pigs

  • Almeida, Ferdinando N.;Vazquez-Anon, Mercedes;Escobar, Jeffery
    • Asian-Australasian Journal of Animal Sciences
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    • 제30권7호
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    • pp.985-993
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    • 2017
  • Objective: The objective of this study was to evaluate increasing doses of a novel microbial phytase (Cibenza Phytaverse, Novus International, St. Charles, MO, USA) on standardized total tract digestibility (STTD) of P in canola meal (CM), corn, corn-derived distiller's dried grains with solubles (DDGS), rice bran (RB), sorghum, soybean meal (SBM), sunflower meal (SFM), and wheat. Methods: Two cohorts of 36 pigs each (initial body weight = $78.5{\pm}3.7kg$) were randomly assigned to 2 rooms, each housing 36 pigs, and then allotted to 6 diets with 6 replicates per diet in a randomized complete block design. Test ingredient was the only dietary source of P and diets contained 6 concentrations of phytase (0, 125, 250, 500, 1,000, or 2,000 phytase units [FTU]/kg) with 0.4% of $TiO_2$ as a digestibility marker. Feeding schedule for each ingredient was 5 d acclimation, 5 d fecal collection, and 4 d washout. The STTD of P increased (linear or exponential $p{\leq}0.001$) with the inclusion of phytase for all ingredients. Results: Basal STTD of P was 37.6% for CM, 37.6% for corn, 68.6% for DDGS, 10.3% for RB, 41.2% for sorghum, 36.7% for SBM, 26.2% for SFM, and 55.1% for wheat. The efficiency of this novel phytase to hydrolyze phytate is best described with a broken-line model for corn, an exponential model for CM, RB, SBM, SFM, and wheat, and a linear model for DDGS and sorghum. Based on best-fit model the phytase dose (FTU/kg) needed for highest STTD of P (%), respectively, was 735 for 64.3% in CM, 550 for 69.4% in corn, 160 for 55.5% in SBM, 1,219 for 57.8% in SFM, and 881 for 64.0% in wheat, whereas a maximum response was not obtained for sorghum, DDGS and RB within the evaluated phytase range of 0 to 2,000 FTU/kg. These differences in the phytase concentration needed to maximize the STTD of P clearly indicate that the enzyme does not have the same hydrolysis efficiency among the evaluated ingredients. Conclusion: Variations in enzyme efficacy to release P from phytate in various feedstuffs need to be taken into consideration when determining the matrix value for phytase in a mixed diet, which likely depends on the type and inclusion concentration of ingredients used in mixed diets for pigs. The use of a fixed P matrix value across different diet types for a given phytase concentration is discouraged as it may result in inaccurate diet formulation.

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.

백서 천식에서 면역 증강성 CpG 올리고 뉴클레오티드 투여의 효과 (Effects of Immunostimulatory CpG-Oligodeoxynucleotides on Bronchial Asthma in Rat)

  • 이신형;김제형;정혜철;김경규;정기환;김병규;이승헌;박상면;신철;조재연;심재정;인광호;유세화;강경호
    • Tuberculosis and Respiratory Diseases
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    • 제50권1호
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    • pp.12-28
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    • 2001
  • 배경 : 면역 증강성 CpG 올리고 뉴클레오티드(immunostimulatory CpG-oligodeoxynucleotides, ISS CpG-ODN)는 $T_{H1}$ 형 면역 반응은 항진시키고, $T_{H2}$ 형의 반응은 감소시키는 것으로 보고되고 있다. 본 연구에서는 백서 천식 모델에서 ISS CpG-ODN으로 인한 면역 반응의 변화가 천식의 주요한 병태 생리 현상인, 기도 과민성, 호산구성 염증 및 점액 과다 분비에 미치는 효과에 대하여 고찰하고자 하였다. 대상 및 방법 : 천식 모델을 형성하지 않은 10마리의 정상 대조군과 ovalbumin(OVA)의 감작 및 유발로 천식 모델이 형성된 26마리의 백서를, 천식 대조군 11마리, 천식-CpG 치료군 15마리로 나누어 실험하였다. 천식-CpG 치료군은 연구 16일과 20일에 ISS CpG-ODN을, 천식 대조군은 생리 식염수를 투여하였다. CpG-ODN 혹은 생리 식염수 투여 후, 특이 기도 저항, 기관지 폐포 세척액(bronchoalveolar lavage fluid, BALF) 내의 $T_{H1}$ 형 사이토카인 (cytokine)인 IFN-${\gamma}$$T_{H2}$ 형 사이토카인인 IL-4의 농도 및 호산구의 분획, 폐조직 내 호산구의 침윤 및 배상 세포의 이형성과 MUC5AC 유전자의 발현을 고찰하였다. 결과 : ISS CpG-ODN 투여 후 천식 대조군과 비교하여, 천식-CpG 치료군에서 기관지 폐포 세척액 내에서 IFN-${\gamma}$의 농도는 유의하게 높았고, IL-4의 농도는 유의하게 낮았다. 특이 기도 저항, 기관지 폐포 세척액 내의 호산구의 분획 및 폐조직에서의 호산구의 침윤은 천식-CpG 치료군에서 천식 대조군에 비하여 유의하게 감소하였다. 그러나 점액 과다 분비의 지표인 배상 세포의 이형성 및 MUC5AC 유전자의 발현 정도는 천식 대조군과 천식-CpG 치료군간에 유의한 차이가 없었다. 결론 : 백서 천식 모델에서 면역 증강성 CpG 올리고 뉴클레오티드는 $T_{H1}$ 형 면역 반응은 항진시키고, $T_{H2}$ 형의 반응은 감소시킴으로써, 천신의 주요한 병태 생리 현상인 기도 과민성 및 호산구서 염증은 억제하나, 점액과다 분비에는 유의한 영향이 없었다.

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Estimation of the Optimal Ratio of Standardized Ileal Digestible Threonine to Lysine for Finishing Barrows Fed Low Crude Protein Diets

  • Xie, Chunyuan;Zhang, Shihai;Zhang, Guijie;Zhang, Fengrui;Chu, Licui;Qiao, Shiyan
    • Asian-Australasian Journal of Animal Sciences
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    • 제26권8호
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    • pp.1172-1180
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    • 2013
  • Two experiments were conducted to determine the standardized ileal digestible (SID) lysine (Lys) requirement and the ideal SID threonine (Thr) to Lys ratio for finishing barrows. In Exp. 1, 120 barrows with an average body weight of $72.8{\pm}3.6$ kg were allotted to one of six dietary treatments in a randomized complete block design conducted for 35 d. Each diet was fed to five pens of pigs containing four barrows. A normal crude protein (CP) diet providing 15.3% CP and 0.71% SID Lys and five low CP diets providing 12% CP with SID Lys concentrations of 0.51, 0.61, 0.71, 0.81 and 0.91% were formulated. Increasing the SID Lys content of the diet resulted in an increase in weight gain (linear effect p = 0.04 and quadratic effect p = 0.08) and an improvement in feed conversion ratio (FCR) (linear effect p = 0.02 and quadratic effect p = 0.02). For weight gain and FCR, the estimated SID Lys requirement of finishing barrows were 0.71 and 0.71% (linear broken-line analysis), 0.79 and 0.78% (quadratic analysis), respectively. Exp. 2 was a 26 d dose-response study using SID Thr to Lys ratios of 0.56, 0.61, 0.67, 0.72 and 0.77. A total of 138 barrows weighing $72.5{\pm}4.4$ kg were randomly allotted to receive one of the five diets. All diets were formulated to contain 0.61% SID Lys (10.5% CP), which is slightly lower than the pig's requirement. Weight gain was quadratically (p = 0.03) affected by SID Thr to Lys ratio while FCR was linearly improved (p = 0.02). The SID Thr to Lys ratios for maximal weight gain and minimal FCR and serum urea nitrogen (SUN) were 0.67, 0.71 and 0.64 using a linear broken-line model and 0.68, 0.78 and 0.70 using a quadratic model, respectively. Based on the estimates obtained from the broken-line and quadratic analysis, we concluded that the dietary SID Lys requirement for both maximum weight gain and minimum FCR was 0.75%, and an optimum SID Thr to Lys ratio was 0.68 to maximize weight gain, 0.75 to optimize FCR and 0.67 to minimize SUN for finishing barrows.