• Asian Pacific Journal of Cancer Prevention
• /
• 제14권6호
• /
• pp.3963-3967
• /
• 2013

Background: The presence of Epstein-Barr virus (EBV) in Non-Hodgkin's lymphoma can be identified by immunohistochemistry for detection of EBV latent membrane protein (LMP). The role of EBV as an etiologic agent in the development of non-Hodgkin lymphoma has been supported by detection of high levels of latent membrane protein 1 (LMP-1) expression in tumors. However, no study has been conducted in a Pakistani population up till now to determine the frequency of Epstein-Barr virus positivity. The objective of our study was to determine a value for non-Hodgkin lymphoma patients using EBV LMP-1 immunostaining in our institution. Materials and Methods: This study was carried out at the Department of Histopathology, Armed Forces Institute of Pathology (AFIP), Pakistan from December 2011 to December 2012. It was a cross sectional study. A total of 71 patients who were diagnosed with various subtypes of NHL after histological and EBV LMP-1 immunohistochemical evaluation were studied. Sampling technique was non-probability purposive. Statistical analysis was achieved using SPSS version 17.0. Mean and SD were calculated for quantitative variables like patient age. Frequencies and percentages were calculated for qualitative variables like subgroup of NHL, results outcome of IHC for EBV and gender distribution. Results: Mean age of the patients was $53.6{\pm}16$ years (Mean${\pm}$SD). A total of 50 (70.4%) were male and 21 (29.6%) were female. Some 9 (12.7%) out of 71 cases were positive for EBV-LMP-1 immunostaining, 2 (22.2%) follicular lymphoma cases, 1 (11.1%) case of T-cell lymphoblastic lymphoma, 4 (44.4%) cases of diffuse large B cell lymphomas, 1 (11.1%) mantle cell lymphoma and 1 (11.1%) angioimmunoblastic T cell lymphoma case. Conclusion: In our study, frequency of EBV in NHL is 12.7% and is mostly seen in diffuse large B cell lymphoma. This requires further evaluation to find out whether this positivity is due to co-infection or has a role in pathogenesis.

• 한국산업정보학회논문지
• /
• 제22권6호
• /
• pp.71-84
• /
• 2017

Over the past decade, we have witnessed Serious Debates in MISQ and Other Journals Between Two Camps that have Differing Views on the use of Causal Indicators to Measure Constructs. There is the Camp that advocates Causal Indicators (ADVOCATE) and the Camp that opposes Their Usage (OPPONENT). The Debates have been primarily centered on the OPPONENT's Argument that the Meaning of a Latent Variable is determined by its Outcome Variables. However, Little Effort has been made to Validate the ADVOCATE's Dispute (Against the OPPONENT's Arguments) that the Meaning of a Latent Variable is decided by its Causal Indicators if there is no Misspecification. Our Study precisely examines the Integrity of the Argument. For this, we empirically examine how the two Primary Psychometric Properties-Comprehensiveness and Interrelationship-of Causal Indicators Influence Theory Testing between Latent Variables through Three Different Tests (i.e., Comprehensive Test, Interrelationship Test, and Mixed Test). Conducted on Two Different Datasets, Our Analysis Consistently Reveals that Structural Path Coefficients are Hardly Sensitive to the Changes (i.e., Misspecification) in the Properties of Causal Indicators. The Discovery offers Important Evidence that the Sound Theoretical Logic of a Causal Model is not in Sync with the Empirical Mechanism of Parameter Estimation. This Underscores that a Latent Variable Formed by Causal Indicators is empirically an elusive notion that is Difficult to Operationalize. As Our Results have Significant Implications on the Integrity of Numerous IS studies which have conducted Theory or Hypothesis Testing Using Causal Indicators, we strongly advocate Open Discussions among Methodologists regarding Our Findings and Their Implications for Both Published IS Research and Future Practices.

• 아동학회지
• /
• 제28권5호
• /
• pp.127-141
• /
• 2007

The purpose of this research was to analyze the trajectory of child's academic attainment and the effect of family socioeconomic background on the trajectory. Data were part of the Korea Youth Panel Survey 2003-2005(Middle School 2) and were analyzed by Latent Growth Curve Modeling(LGM). The degree of child's academic attainment decreased over 3 years. Socioeconomic status variables that influenced academic trajectory were family poverty, parent's attainments in scholarship, and family structure. Findings from this study suggest that societal support for low socioeconomic status families is needed for improvement of academic attainment of their children.

• 대한치과교정학회지
• /
• 제49권3호
• /
• pp.170-180
• /
• 2019

Objective: The purpose of this study was to investigate the relationship between the facial skeletal patterns and the shape of the mandibular symphysis in adults with malocclusion by using a structural equation model (SEM). Methods: Ninety adults who had malocclusion and had records of facial skeletal measurements performed using cone-beam computed tomography were selected for this study. The skeletal measurements were classified into three groups (vertical, anteroposterior, and transverse). Cross-sectional images of the mandibular symphysis were analyzed using generalized Procrustes and principal component (PC) analyses. A SEM was constructed after the factors were extracted via factor analysis. Results: Two factors were extracted from the transverse, vertical, and anteroposterior skeletal measurements. Latent variables were extracted for each factor. PC1, PC2, and PC3 were selected to analyze the variations of the mandibular symphyseal shape. The SEM was constructed using the skeletal variables, PCs, and latent variables. The SEM showed that the vertical latent variable exerted the most influence on the mandibular symphyseal shape. Conclusions: The relationship between the skeletal pattern and the mandibular symphysis was analyzed using a SEM, which showed that the vertical facial skeletal pattern had the highest effect on the shape of the mandibular symphysis.

• Wind and Structures
• /
• 제39권3호
• /
• pp.175-190
• /
• 2024

Aerodynamic shape optimization is very useful for enhancing the performance of wind-sensitive structures. However, shape parameterization, as the first step in the pipeline of aerodynamic shape optimization, still heavily depends on empirical judgment. If not done properly, the resulting small design space may fail to cover many promising shapes, and hence hinder realizing the full potential of aerodynamic shape optimization. To this end, developing a novel shape parameterization scheme that can reflect real-world complexities while being simple enough for the subsequent optimization process is important. This study proposes a machine learning-based scheme that can automatically learn a low-dimensional latent representation of complex aerodynamic shapes for bluff-body wind-sensitive structures. The resulting latent representation (as design variables for aerodynamic shape optimization) is composed of both discrete and continuous variables, which are embedded in a hierarchy structure. In addition to being intuitive and interpretable, the mixed discrete and continuous variables with the hierarchy structure allow stakeholders to narrow the search space selectively based on their interests. As a proof-of-concept study, shape parameterization examples of tall building cross sections are used to demonstrate the promising features of the proposed scheme and guide future investigations on data-driven parameterization for aerodynamic shape optimization of wind-sensitive structures.

• 교육시설 논문지
• /
• 제26권5호
• /
• pp.3-10
• /
• 2019

This study has a purpose to profile local sectors into meaningful groups by using facilities rates of Social Overhead Capital(SOC) for daily life. Comparing SOC for daily life among the meaningful groups, the profiling and comparison results bring the comprehensive understanding about the educational facilities in local sectors. For the research purpose, this study utilized Latent Profile Analysis(LPA) by using variables such as population, road information, SOC for daily life, usage of land, possession of land, and appraised value of land from the 2018 Geographic Information System(GIS) dataset of Gwangjin-gu, where is one of the administrative district of Seoul City. Results showed that there are four latent groups of sectors among 904 local sectors(100 squared-meters sector per each) in Gwangjin-gu. By comparing the four latent groups by using LPA, the results diagnose each sector's status and help to improve the policy about educational facilities. Specifically, by using dataset for SOC of daily life, there are four groups of local sectors and each group has different features. Based on the different features of local sector groups, there can be improved management of educational facilities matching with each group's features.

• 응용통계연구
• /
• 제35권6호
• /
• pp.739-754
• /
• 2022

텍스트 데이터는 일반적으로 많은 변수를 포함하고 있으며 변수들 사이의 연관성도 높아 통계 분석의 정확성, 효율성 등에서 문제가 생길 수 있다. 이러한 문제점에 대처하기 위해 목표 변수가 주어진 지도 학습에서는 목표 변수를 잘 설명할 수 있는 단어들을 선택하여 이 단어들만 통계 분석에 이용하기도 한다. 반면, 비지도 학습에서는 목표 변수가 주어지지 않으므로 지도 학습에서와 같은 단어 선택 절차를 활용하기 어렵다. 이 연구에서는 토픽 모형을 이용하여 지도 학습에서의 목표 변수를 대신할 수 있는 토픽을 생성하고 각 토픽별로 연관성이 높은 단어들을 선택하는 단어 선택 절차를 제안한다. 제안된 절차를 실제 텍스트 데이터에 적용한 결과, 단어 선택 절차를 이용하면 많은 토픽에서 공통적으로 자주 등장하는 단어들을 제거함으로써 토픽을 더 명확하게 식별할 수 있었다. 또한, 군집 분석에 적용한 결과, 군집과 범주 사이에 높은 연관성을 가지는 군집 분석 결과를 얻을 수 있는 것으로 나타났다. 목표 변수에 대한 정보없이 토픽 모형을 이용하여 선택한 단어들을 분류 분석에 적용하였을 때 목표 변수를 이용하여 단어들을 선택한 경우와 비슷한 분류 정확성을 얻을 수 있음도 확인하였다.

• 한국조사연구학회지:조사연구
• /
• 제18권2호
• /
• pp.67-98
• /
• 2017

본 연구의 목적은 학교폭력 잠재집단이 각 유형별 피해경험과 가해경험에 따라 어떻게 나눠지는지 살펴보고, 이러한 잠재집단 분류에 개인과 학교 요인들이 미치는 영향을 검증하는 것이다. 이를 위해 서울교육종단연구(SELS2010)의 초등학교 4학년 패널의 5차 자료 중 학교폭력을 한번 이상 경험한 학생 2,195명의 학교폭력 피해 및 가해경험에 대해 다층 잠재프로파일 모형(multilevel latent profile model)을 적용하여 분석하였다. 분석 결과, 학교폭력 가해 및 피해경험을 종류별, 수준별로 모두 고려하였을 때 가해피해 고수준집단(1.7%), 가해위주집단(2.1%), 피해위주집단(3.7%), 언어적 폭력경험집단(92.5%)의 4가지의 집단으로 분류되었다. 영향요인 검증 결과, 학생수준에서 성별, 탄력성, 자기통제력, 친구관계, 부모자녀관계가 유의하게 나타났고, 학교수준에서 교사학생관계, 학교폭력 예방교육, 학교 내 성비가 유의하게 나타났다. 본 연구는 학교폭력 가해와 피해 경험을 모두 포함하여 빈도별, 유형별로 집단을 한 번에 분류하여 이론적 논의를 확장하였고, 다층자료임을 반영하여 개인수준과 학교수준의 영향요인을 동시에 검증했다는 점에서 의의가 있다.

• 응용통계연구
• /
• 제33권4호
• /
• pp.365-377
• /
• 2020

선형모형에서 두개 이상의 설명변수들 사이에 존재하는 다중공선성 문제를 변수들 간에 내재되어 있는 공통의 구조인 인자를 구성하고, 인자들을 회귀변수로 사용하여 해결하는 인자회귀모형에 대하여 논의한다. 무한개로 가정 가능한 내재된 인자 중 유의미한 인자적재행렬을 구성하기 위하여 벌점모수의 값이 큰 LASSO 사전분포를 적용하는 베이지안 추정법을 사용한다. 결정된 인자적재행렬과 다른 모수들의 추정값을 각 설명변수의 선형모수로 역변환 하여, 새로운 관측값에 대한 예측 모형으로도 사용한다. 제안한 방법을 제품 서비스 관리 자료에 적용하여 정해진 인자의 개수에 대한 인자가 일반적인 공통인자회귀모형과 동일한 결과를 나타냄을 확인하였고, 일반적인 공통인자회귀모형과 비교를 위해 계산한 평균 제곱 오차값이 더 작다는 것을 알 수 있었다.

• 지역사회간호학회지
• /
• 제30권4호
• /
• pp.449-459
• /
• 2019

Purpose: The aim of this study is to explore different types of self-rated health trajectories among one-person households in Korea. Methods: We used five time-point data derived from Korea Health Panel (2011~2015). A latent growth curve modeling was used to assess the overall feature of self-rated health trajectory in one-person households, and a latent class growth modeling was used to determine the number and shape of trajectories. We then applied multinomial logistic regression on each class to explore the predicting variables. Results: We found that the overall slope of self-rated health in one-person households decreases. In addition, latent class analysis demonstrated three classes: 1) High-Decreasing class (i.e., high intercept, significantly decreasing slope), 2) Moderate-Decreasing class (i.e., average intercept, significantly decreasing slope), and 3) Low-Stable class (i.e., low intercept, flat and nonsignificant slope). The multinomial logistic regression analysis showed that the predictors of each class were different. Especially, one-person households with poor health condition early were at greater risk of being Low-Stable class compared with High-Decreasing class group. Conclusion: The findings of this study demonstrate that more attentions to one-person households are needed to promote their health status. Policymakers may develop different health and welfare programs depending on different characteristics of one-person household trajectory groups in Korea.