Earticle

This study examined the relationship between moderate-to-vigorous physical activity (MVPA), sedentary behavior (SB), and metabolic syn-drome, employing both cross-sectional and Mendelian randomization methods to enhance causal inference. The cross-sectional analysis in-cluded adults aged 20 years and older with arthritis (n=4,227) from the National Health and Nutrition Examination Survey and assessed the as-sociations between MVPA, SB, and metabolic syndrome. Mendelian randomization analysis used genome-wide association studies to vali-date causal relationships, employing instrumental variables selected from single nucleotide polymorphisms linked to accelerometer-based physical activity (fraction of time with accelerations >425 milli-gravi-ties) and SB. The primary Mendelian randomization methods included inverse variance weighting and Bayesian Weighted Mendelian Ran-domization. Sensitivity analyses, including Mendelian Randomization- Egger intercept test, the weighted median method, and Mendelian Ran-domization Pleiotropy RESidual Sum and Outlier, were conducted to en-sure result robustness. Cross-sectional analysis revealed a significant association between higher levels of MVPA and reduced SB with a lower prevalence of metabolic syndrome. Participants in the high MVPA/low SB group demonstrated lower odds of metabolic syndrome (odds ratio [OR], 0.40; 95% confidence interval [CI], 0.29–0.56), hypertension (OR, 0.55; 95% CI, 0.40–0.75), fasting glucose (OR, 0.52; 95% CI, 0.35–0.77), and waist circumference (OR, 0.34; 95% CI, 0.22–0.54). Mendelian ran-domization analysis confirmed a causal relationship, showing that phys-ical activity decreases risk factors for metabolic syndrome, while SB exacerbates them. This study emphasizes the critical roles of regular physical activity and reduced SB in mitigating the risk of metabolic syn-drome, especially among older adults with arthritis.

현재 상용화된 온라인 시험 플랫폼들은 문제 목록 및 출제의 체계화가 부족하고 대규모 인원에 대한 이 용 접근성이 낮다. 이런 단점을 보완하고 평가의 교육적 효과와 효율성을 확대하기 위해 변수 랜덤 방식으로 출제 문제를 다변화하는 온라인 시험 및 평가 시스템을 개발했다. 본 플랫폼은 랜덤 변수 다지선다형 객관식 문제출제, 문제 미리보기-원클릭 시험지 구성, 교수자들과 문제은행 및 시험지 공유, 및 개별 학생의 접속상태 감지/알림과 같은 독창적인 기능을 구비하고 있다. 또한 모바일 기기에서도 사용할 수 있도록 개발되어 대규모 수강 인원의 학 습역량 평가에 대한 사용 편의성 및 효율성도 높였다. 이러한 장점들로 인해, 기존의 플랫폼들과 차별화된 방향으로 개발된 본 플랫폼이 종이 기반 시험을 대체할 수 있는 효과적이고 효율적인 평가 수단으로 위치할 수 있을 것으로 기대한다.

The current commercial online assessment platforms have a lack of systematization for question listing and testing structures, and low accessibility to a large number of students. To address these constraints and enhance the effectiveness and efficiency of assessments in education, we have developed an online assessment platform that diversifies test questions employing a variable randomization method. Our platform incorporates unique features, such as testing with random-variable multiple-choice questions, test sheet configuration by pre-previewing and one-click problem selection, convenient sharing of question lists and test sheets with other instructors, and monitoring/alarming connectivity status for individual students. Additionally, it was developed to be compatible with mobile devices, increasing usage efficiency and convenience for a large number of students. With these aspects, we believe our platform, developed with distinct directions from existing platforms, would position itself as an efficient and effective assessment tool with the potential to replace paper-based tests.

패스워드 기반 인증[1]은 사용자의 기억에 의존하는 인증방식으로 시스템 구현이 간단하여 컴퓨터 산업의 태동시부터 널리 사용되어져 왔다. 토큰 인증[2][3]은 서버가 발급한 특정 토큰을 소유하고 있 다는 것을 보임으로써 사용자를 인증하는 방식으로 오늘날의 대규모 웹서비스 환경에서 서버의 부담 을 줄여줄 수 있다는 효용성이 있어서 자동로그인 방식으로 널리 사용되고 있다. 그러나 이러한 인증 방식은 고정된 패스워드나 토큰이 통신로를 통해 평문으로 반복 전달되기 때문에 도청공격 등으로 노출될 수 있는 위험이 있어서 반드시 암호화된 통신 환경에서 사용되어야 한다. 고정된 패스워드 인 증의 취약성을 해결하기 위해 TOTP(Time-Based One-Time Password)[4] 방식이 사용될 수 있는데 이 것은 매 로그인시마다 공유되고 있는 고정된 패스워드와 현재의 시간정보를 입력으로 하여 난수화된 로그인 정보를 생성하여 제출하게 하는 것으로 도청공격에 대응할 수 있게 하였다. 이 논문에서는 TOTP의 난수화 방식을 일부 응용하여 현재 널리 사용되고 있는 웹서비스에서의 고 정된 토큰 인증을 시간정보를 이용하여 난수화할 수 있는 방법을 제시한다. 이를 이용하면 토큰인증 정보가 시간에 따라 달라져서 도청공격을 무력화시킬 수 있다. 이러한 방법론은 기존에 사용되던 JWT[3] 토큰 인증 시스템을 약간 수정하여 난수화된 자동로그인을 제공할 수 있다는 장점이 있다.

Password-based authentication[1] depends on human’s memory and is simple to implement that it had been widely used in the real world from the beginning of computer industry. Token-based authentication[2][3] is an authentication of user by showing that the user possesses a specific token that was issued by the server, and it is widely used to implement auto login in current massive web service environment since it can greatly reduce server’s workload. But in these authentication protocols fixed information is sent to the server repeatedly over the communication channel that it is subject to eavesdropping attack, thus these authentication protocols have to be executed over a secure communication channel such as SSL/TLS. To solve these eavesdropping attack TOTP(Time-based One Time Password) [4] protocol can be used which produces randomized authentication information depending on shared password and current time. In this paper we propose a new randomized token-based authentication protocol by using TOTP approach to modified token-based authentication. This protocol can thwart eavesdropping attack since the authentication information changes depending on time. This approach can provide randomized token- based authentication with simple modification of traditional JWT authentication.

In this letter, we propose a data randomization scheme for endurance and interference mitigation of deeply-scaled multilevel flash memory. We address the relationships between data patterns and the raw bit error rate. An on-chip pseudorandom generator composed of an address-based seed location decoder is developed and evaluated with respect to uniformity. Experiments performed with 2x-nm and 4x-nm NAND flash memory devices illustrate the effectiveness of our scheme. The results show that the error rate is reduced up to 86% compared to that of a conventional cycling scheme. Accordingly, the endurance phenomenon can be mitigated through analysis of interference that causes tech shrinkage.

In this paper, we propose two power randomization schemes for the random beamforming (RBF) based MIMO systems in cellular downlink. In the proposed system, a BS randomizes not only the pre-coding matrix but also the power allocation matrix, while the conventional RBF system allocates an equal power to each transmit stream. The proposed water-filling based power randomization scheme (Scheme-I) is proper in the low SNR values and the proposed random-power based randomization scheme (Scheme-II) is proper in the high SNR values. The proposed system with the power randomization outperforms the conventional RBF system which allocates the same power for each data stream.

Basu (1980) examined Fisher Randomization Test (FRT) of matched pair experimental data with critical point of view. Additionally, Lane (1980) pointed out that "the experimenter may be interested in a weaker notion of equality between two treatments, " than the notion of equality which FRT relies on. In this study, a randomization test is developed so that it can test a weaker hypothesis of equality. equality.

The role of randomization is examined with regard to the Simpson's paradox. When the sample size n is large, it is known that the randomization is powerful in preventing the Simpson's paradox. In the present study, the question is whether is performs well for small n.

Mendelian randomization (MR), a powerful statistical tool for causal inference, has been widely applied in various fields of medical research, even extending to economics and psychology. In hepatology, MR has been utilized to identify risk factors and potential therapeutic targets for liver diseases, including metabolic dysfunction-associated steatotic liver disease, cholestatic and autoimmune liver diseases, and hepatobiliary cancer. MR can provide evidence of causation via associations between genetic variants, modifiable exposures and liver disease occurrence or outcomes, using large existing datasets. However, results from MR studies are sometimes scattered, biologically not plausible or even controversial between analyses, potentially reflecting a trend of inappropriate application of this method (e.g., inappropriate selection of genetic instruments, insufficient assessment of horizontal pleiotropy, compromised statistical power, and neglected genetic diversity among different populations), and thus hinder the translation of MR findings from bench to bedside. Assessing these critical issues and pinpointing bona fide evidence are essential but quite challenging for clinicians. In this review, we aim to introduce the MR method to hepatologists and provide a comprehensive overview of the current MR findings that are relevant for hepatologists. Furthermore, we will discuss how to evaluate the quality of MR publications, interpret MR findings, and illustrate good practice of using MR studies in hepatology.

Privacy preserving microdata publication has received wide attention. In this paper, we investigate the randomization approach and focus on attribute disclosure under linking attacks. We give efficient solutions to determine optimal distortion parameters, such that we can maximize utility preservation while still satisfying privacy requirements. We compare our randomization approach with l-diversity and anatomy in terms of utility preservation (under the same privacy requirements) from three aspects (reconstructed distributions, accuracy of answering queries, and preservation of correlations). Our empirical results show that randomization incurs significantly smaller utility loss.

Objective Previous studies have discovered a correlation between cigarette smoking and cortical thickness and surface area, but the causal relationship remains unclear. The objective of this investigation is to scrutinize the causal association between them.Methods To derive summary statistics from a genome-wide association study (GWAS) on cortical thickness, surface area, and four smoking behaviors: 1) age of initiation of regular smoking (AgeSmk); 2) smoking initiation (SmkInit); 3) smoking cessation (SmkCes); 4) cigarettes per day (CigDay). Linkage disequilibrium score regression (LDSC) was employed to examine genetic association analysis. Furthermore, for traits with significant genetic associations, Mendelian randomization (MR) analyses were conducted.Results The LDSC analysis revealed nominal genetic correlations between AgeSmk and right precentral surface area, left caudal anterior cingulate surface area, left cuneus surface area, left inferior parietal surface area, and right caudal anterior cingulate thickness, as well as between CigDay and left caudal middle frontal surface area, between SmkCes and left entorhinal thickness, and between SmkInit and left rostral anterior cingulate surface area, right rostral anterior cingulate thickness, and right superior frontal thickness (rg=-0.36?0.29, p<0.05). MR analysis showed a unidirectional causal association between left caudal middle frontal surface area and CigDay (β_IVW=0.056, p_Bonferroni=2×10^-4).Conclusion Left caudal middle frontal surface area has the potential to serve as a significant predictor of smoking behavior.

In clinical trials subjects are avalible sequentially and must be assigned to treatments immediately. Completely randomized procedure for the allocation of treatments to each subject may result in severe imbalance among the number of subjects in treatment groups, especially for small experiments or interim analyses of large experiments. In this study, restricted randomization methods such as biased coin designs (Efron, 1971), permuted block design, and truncated binomial design are compared to teh completely randomized design in the presence of selection and/or accidential bias by Monte Carlo simulations.

Address Space Randomization(ASR)은 성능 부하가 없고 광범위한 데이터 메모리 영역의 보호가 가능한 우수한 방어 기법이다. ASR은 사용 가능한 데이터 메모리 영역 내에서 변수를 재배치 함으로써 공격자에게 변수의 주소를 숨기는데, 데이터 메모리 영역의 크기가 한정되어서 무차별 공격에 취약한 단점이 있다. 본 논문은 기존 ASR의 단점을 제거하기 위한 다중 ASR 기법을 제시한다. 다중 ASR 기법은 데이터 메모리 영역을 원본 및 복사 영역으로 나누고 각 메모리 영역의 변수 값을 비교함으로써 공격을 탐지하고 방어한다. 다중 ASR에서 각 데이터 메모리 영역의 변수는 서로 다른 순서로 배치되므로 한 번의 공격을 통해 동시에 동일한 변수 값을 조작하는 것은 불가능하다. 다중 ASR이 적용된 프로그램은 중복 수행으로 인해 비교적 높은 성능 부하를 보이나, 실제 공격 대상이 되는 웹서버 등 I/O 처리가 많이 요구되는 프로그램의 경우 40%~50% 정도의 성능 부하를 보인다. 아울러 본 논문에서는 프로그램에 다중 ASR을 적용하기 위한 변환프로그램을 개발하였다.

ASR is an excellent program security technique that protects various data memory areas without run-time overhead. ASR hides the addresses of variables from attackers by reordering variables within a data memory area; however, it can be broken by brute force attacks because of a limited data memory space. In this paper, we propose Multiple ASR to overcome the limitation of previous ASR approaches. Multiple ASR separates a data memory area into original and duplicated areas, and compares variables in each memory area to detect an attack. In original and duplicated data memory areas variables are arranged in the opposite order. This makes it impossible to overwrite the same variables in the different data areas in a single attack. Although programs with Multiple ASR show a relatively high run-time overhead due to duplicated execution, programs with many I/O operations such as web servers, a favorite attack target, show 40~50% overhead. In this paper we develop and test a tool that transforms a program into one with Multiple ASR applied.

Background and Purpose To explore the causal relationships of elements of the exposome with ischemic stroke and its subtypes at the omics level and to provide evidence for stroke prevention. Methods We conducted a Mendelian randomization study between exposure and any ischemic stroke (AIS) and its subtypes (large-artery atherosclerotic disease [LAD], cardioembolic stroke [CE], and small vessel disease [SVD]). The exposure dataset was the UK Biobank involving 361,194 subjects, and the outcome dataset was the MEGASTROKE consortium including 52,000 participants. Results We found that higher blood pressure (BP) (systolic BP: odds ratio [OR], 1.02; 95% confidence interval [CI], 1.01 to 1.04; diastolic BP: OR, 1.03; 95% CI, 1.01 to 1.05; pulse pressure: OR, 1.03; 95% CI, 1.00 to 1.06), atrial fibrillation (OR, 1.18; 95% CI, 1.13 to 1.25), and diabetes (OR, 1.13; 95% CI, 1.07 to 1.18) were significantly associated with ischemic stroke. Importantly, higher education (OR, 0.69; 95% CI, 0.60 to 0.79) decreased the risk of ischemic stroke. Higher systolic BP (OR, 1.06; 95% CI, 1.02 to 1.10), pulse pressure (OR, 1.08; 95% CI, 1.02 to 1.14), diabetes (OR, 1.28; 95% CI, 1.13 to 1.45), and coronary artery disease (OR, 1.58; 95% CI, 1.25 to 2.00) could cause LAD. Atrial fibrillation could cause CE (OR, 1.90; 95% CI, 1.71 to 2.11). For SVD, higher systolic BP (OR, 1.04; 95% CI, 1.00 to 1.07), diastolic BP (OR, 1.06; 95% CI, 1.01 to 1.12), and diabetes (OR, 1.22; 95% CI, 1.10 to 1.36) were causal factors. Conclusions The study revealed elements of the exposome causally linked to ischemic stroke and its subtypes, including conventional causal risk factors and novel protective factors such as higher education.

Background: Observational studies have suggested associations between dietary polyunsat- urated fatty acids (PUFAs) and cancer risk; however, causal inference regarding skin cancer remains limited due to potential recall bias, confounding, and reverse causation. Objective: This study aimed to evaluate the causal association between genetically predicted circulating PUFA levels and the risk of skin cancers, including basal cell carcinoma (BCC), squa- mous cell carcinoma (SCC), and melanoma. Methods: We conducted a 2-sample Mendelian randomization (MR) study using genome-wide association study summary statistics from the UK Biobank (PUFAs, n=115,006) and the FinnGen consortium (BCC, n=26,272; SCC, n=4,663; melanoma, n=5,753). Genetic instruments were derived for omega-3, docosahexaenoic acid, omega-6, linoleic acid, and the omega-6:3 ratio. Multiple MR methods?including inverse-variance weighted, MR-Egger, weighted median, weighted mode, and MR-PRESSO?were applied to test for consistency and assess pleiotropy and heterogeneity. Results: A higher genetically predicted linoleic acid to total fatty acid ratio was associated with a significantly lower risk of BCC and SCC. Conversely, higher genetically proxied serum omega-3 levels were associated with increased risks of BCC, SCC, and melanoma. The risk effect on SCC was attenuated upon exclusion of rs174528, a variant in the fatty acid desaturase 1 (FADS1 ) gene, suggesting a role for endogenous PUFA metabolism in carcinogenesis. Conclusion: This MR analysis supports a causal role of circulating PUFAs in skin cancer devel- opment and highlights the importance of FADS-mediated endogenous PUFA metabolism. These findings provide novel insights into the genetic and metabolic underpinnings of skin cancer susceptibility.