• 제목/요약/키워드: Subgroup Method

검색결과 189건 처리시간 0.029초

Corporate Social Responsibility and Firm Risk: Controversial Versus Noncontroversial Industries

  • ERIANDANI, Rizky;WIJAYA, Liliana Inggrit
    • The Journal of Asian Finance, Economics and Business
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    • 제8권3호
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    • pp.953-965
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    • 2021
  • This study aims to analyze the benefits of corporate social responsibility (CSR) performance on corporate risk in controversial and non-controversial industries. The hypothesis of this study is based on the conflicting effects of industry type on CSR and firm risk. The research sample consisted of 927 companies listed on the Indonesia Stock Exchange from 2016 to 2019. The main method for data processing was the ordinary least square method and subgroup analysis as a robustness test. The findings suggest that the performance of CSR can reduce corporate risk. However, the impact was only significant for non-controversial firms and weakened for controversial industries. These results support risk management and signaling theory. Firm risk in this study reflects the company's total risk, further research can categorize it into systematic and idiosyncratic risk. Besides, the number of samples of controversial industry research is not as much as non-controversial; further research can use paired samples. Regulators can use the results to create a new policy regarding CSR implementation. This study contributes to the existing literature by showing that the ability of social responsibility to reduce corporate risk only works in non-controversial industries. This result may be due to the controversial industry receiving negative stigma from its stakeholders.

A pooled Bayes test of independence using restricted pooling model for contingency tables from small areas

  • Jo, Aejeong;Kim, Dal Ho
    • Communications for Statistical Applications and Methods
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    • 제29권5호
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    • pp.547-559
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    • 2022
  • For a chi-squared test, which is a statistical method used to test the independence of a contingency table of two factors, the expected frequency of each cell must be greater than 5. The percentage of cells with an expected frequency below 5 must be less than 20% of all cells. However, there are many cases in which the regional expected frequency is below 5 in general small area studies. Even in large-scale surveys, it is difficult to forecast the expected frequency to be greater than 5 when there is small area estimation with subgroup analysis. Another statistical method to test independence is to use the Bayes factor, but since there is a high ratio of data dependency due to the nature of the Bayesian approach, the low expected frequency tends to decrease the precision of the test results. To overcome these limitations, we will borrow information from areas with similar characteristics and pool the data statistically to propose a pooled Bayes test of independence in target areas. Jo et al. (2021) suggested hierarchical Bayesian pooling models for small area estimation of categorical data, and we will introduce the pooled Bayes factors calculated by expanding their restricted pooling model. We applied the pooled Bayes factors using bone mineral density and body mass index data from the Third National Health and Nutrition Examination Survey conducted in the United States and compared them with chi-squared tests often used in tests of independence.

Detection of Circulating Tumor Cells in Breast Cancer Patients: Prognostic Predictive Role

  • Turker, Ibrahim;Uyeturk, Ummugul;Sonmez, Ozlem Uysal;Oksuzoglu, Berna;Helvaci, Kaan;Arslan, Ulku Yalcintas;Budakoglu, Burcin;Alkis, Necati;Aksoy, Sercan;Zengin, Nurullah
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권3호
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    • pp.1601-1607
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    • 2013
  • A determination of circulating tumor cell (CTC) effectiveness for prediction of progression-free survival (PFS) and overall survival (OS) was conducted as an adjunct to standard treatment of care in breast cancer management. Between November 2008 and March 2009, 22 metastatic and 12 early stage breast carcinoma patients, admitted to Ankara Oncology Training and Research Hospital, were included in this prospective trial. Patients' characteristics, treatment schedules and survival data were evaluated. CTC was detected twice by CellSearch method before and 9-12 weeks after the initiation of chemotherapy. A cut-off value equal or greater than 5 cells per 7.5 ml blood sample was considered positive. All patients were female. Median ages were 48.0 (range: 29-65) and 52.5 (range: 35-66) in early stage and metastatic subgroups, respectively. CTC was positive in 3 (13.6%) patients before chemotherapy and 6 (27.3%) patients during chemotherapy in the metastatic subgroup whereas positive in only one patient in the early stage subgroup before and during chemotherapy. The median follow-up was 22.0 (range: 21-23) and 19.0 (range: 5-23) months in the early stage and metastatic groups, respectively. In the metastatic group, both median PFS and OS were significantly shorter in any time CTC positive patients compared to CTC negative patients (PFS: 4.0 vs 14.0 months, Log-Rank p=0.013; and OS: 8.0 months vs. 20.5 months, Log-Rank p<0.001). OS was affected from multiple visceral metastatic sites (p=0.055) and higher grade (p=0.044) besides CTC positivity (log rank p<0.001). Radiological response of chemotherapy was also correlated with better survival (p<0.001). As a result, CTC positivity was confirmed as a prospective marker even in a small patient population, in this single center study. Measurement of CTC by CellSearch method in metastatic breast carcinoma cases may allow indications of early risk of relapse or death with even as few as two measurements during a chemotherapy program, but this finding should be confirmed with prospective trials in larger study populations.

CLUSTERING DNA MICROARRAY DATA BY STOCHASTIC ALGORITHM

  • Shon, Ho-Sun;Kim, Sun-Shin;Wang, Ling;Ryu, Keun-Ho
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.438-441
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    • 2007
  • Recently, due to molecular biology and engineering technology, DNA microarray makes people watch thousands of genes and the state of variation from the tissue samples of living body. With DNA Microarray, it is possible to construct a genetic group that has similar expression patterns and grasp the progress and variation of gene. This paper practices Cluster Analysis which purposes the discovery of biological subgroup or class by using gene expression information. Hence, the purpose of this paper is to predict a new class which is unknown, open leukaemia data are used for the experiment, and MCL (Markov CLustering) algorithm is applied as an analysis method. The MCL algorithm is based on probability and graph flow theory. MCL simulates random walks on a graph using Markov matrices to determine the transition probabilities among nodes of the graph. If you look at closely to the method, first, MCL algorithm should be applied after getting the distance by using Euclidean distance, then inflation and diagonal factors which are tuning modulus should be tuned, and finally the threshold using the average of each column should be gotten to distinguish one class from another class. Our method has improved the accuracy through using the threshold, namely the average of each column. Our experimental result shows about 70% of accuracy in average compared to the class that is known before. Also, for the comparison evaluation to other algorithm, the proposed method compared to and analyzed SOM (Self-Organizing Map) clustering algorithm which is divided into neural network and hierarchical clustering. The method shows the better result when compared to hierarchical clustering. In further study, it should be studied whether there will be a similar result when the parameter of inflation gotten from our experiment is applied to other gene expression data. We are also trying to make a systematic method to improve the accuracy by regulating the factors mentioned above.

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봉화군 장군봉 일대 자연림의 식생유형과 임분특성 (Vegetation Type and Stand Characteristics of Natural Forest in Mt. Janggunbong, Bonghwa-Gun)

  • 변성엽;윤충원
    • 한국환경생태학회지
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    • 제31권3호
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    • pp.297-317
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    • 2017
  • 본 연구는 봉화 장군봉의 자연림을 대상으로 산림식생의 유형을 분류하고, 그에 따른 임분특성을 구명하고자 수행되었다. 2014년 6월부터 2016년 8월까지 식생조사를 실시하였으며, 총 71개소의 식생조사자료를 토대로, 종-면적곡선, 식물사회학적 식생유형분류, 중요치, 종다양도, 일치법, CCA 분석을 실시하였다. 종-면적곡선과 누적종수 추정치를 분석해본 결과, 조사구의 설치는 적절하게 이루어졌으며, 총 227개 분류군(67과 152속 197종 3아종 27변종)이 출현하였다. 식생유형분류를 실시한 결과, 총 7개의 식생단위로 분류되었으며, 최상위 수준에서 신갈나무군락군, 신갈나무군락군은 고로쇠나무군락(동자꽃군과 물참대군), 잣나무군락(시닥나무군과 잣나무전형군), 굴참나무군락(담쟁이덩굴군과 굴참나무전형군)으로 분류되었으며, 담쟁이덩굴군은 담쟁이덩굴전형소군과 호랑버들소군으로 분류되었다. 중요치 분석결과, 식생단위 1~5의 교목층에서는 신갈나무(38.0~70.4%), 식생단위 6은 박달나무(35.3%), 식생단위 7은 소나무(45.4%)가 각각 가장 높게 나타났다. 박달나무와 소나무가 우점하는 식생단위 6과 7은 교목층을 제외한 층위에서 신갈나무와 굴참나무가 높은 중요치를 나타내어, 향후 이들 식생단위는 신갈나무와 굴참나무에 의한 군락이 형성될 것으로 사료되었다. 종다양도는 식생단위 1, 2, 3의 종다양도(2.130~2.353)가 높게 나타났으며, 이는 계곡의 지형적 특성에 의한 영향 때문인 것으로 사료되었다. 일치법과 CCA를 실시한 결과, 식생유형은 해발고도와 가장 높은 상관관계를 가지고 있는 것으로 나타났다.

Artificial Intelligence-Based Colorectal Polyp Histology Prediction by Using Narrow-Band Image-Magnifying Colonoscopy

  • Istvan Racz;Andras Horvath;Noemi Kranitz;Gyongyi Kiss;Henriett Regoczi;Zoltan Horvath
    • Clinical Endoscopy
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    • 제55권1호
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    • pp.113-121
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    • 2022
  • Background/Aims: We have been developing artificial intelligence based polyp histology prediction (AIPHP) method to classify Narrow Band Imaging (NBI) magnifying colonoscopy images to predict the hyperplastic or neoplastic histology of polyps. Our aim was to analyze the accuracy of AIPHP and narrow-band imaging international colorectal endoscopic (NICE) classification based histology predictions and also to compare the results of the two methods. Methods: We studied 373 colorectal polyp samples taken by polypectomy from 279 patients. The documented NBI still images were analyzed by the AIPHP method and by the NICE classification parallel. The AIPHP software was created by machine learning method. The software measures five geometrical and color features on the endoscopic image. Results: The accuracy of AIPHP was 86.6% (323/373) in total of polyps. We compared the AIPHP accuracy results for diminutive and non-diminutive polyps (82.1% vs. 92.2%; p=0.0032). The accuracy of the hyperplastic histology prediction was significantly better by NICE compared to AIPHP method both in the diminutive polyps (n=207) (95.2% vs. 82.1%) (p<0.001) and also in all evaluated polyps (n=373) (97.1% vs. 86.6%) (p<0.001) Conclusions: Our artificial intelligence based polyp histology prediction software could predict histology with high accuracy only in the large size polyp subgroup.

간호사, 비말기 암환자 및 말기 암환자가 지각한 간호요구의 중요도와 제공정도에 대한 비교 (A Comparison of Perceived Nursing Needs among Oncology Nurses, Patients with Non-terminal Cancer and Patients with Terminal Cancer)

  • 최자윤
    • 대한간호학회지
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    • 제35권6호
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    • pp.1135-1143
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    • 2005
  • Purpose: The purpose of this study was to compare the perceived importance and the perceived caring of nursing needs among oncology nurses, patients with non-terminal cancer and patients with terminal cancer. Method: A total of 83 oncology nurses, 56 patients with non-terminal cancer and 39 patients with terminal cancer served as subjects. Data was collected based on the 4-point Likert scale using a self-administered questionnaire from Mar. to Sept. 2004. Finally, data was analyzed using mean, SD, paired-test,. and ANOVA. Results: The score of the perceived importance of nursing needs was higher than that of the perceived performance of nursing needs in all three groups. There was also a difference in the degree of perceived performance of nursing needs among the three groups. In contrast, there was no difference in the total score of the perceived importance of nursing needs among the three groups, unlike the importance of informational and physical needs as a subgroup of perceived importance, where a difference was noted. Conclusions: Strategies should be developed to narrow down these gaps between nurses and patients. In particular, informational and educational programs should be designed for patients with terminal cancer.

멀티캐스팅 정보보안을 위한 그룹키 관리 프로토콜 구현 (Implementation of Group Key Management Protocol for Multicasting Information Security)

  • 홍종준
    • 한국컴퓨터정보학회논문지
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    • 제9권3호
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    • pp.177-182
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    • 2004
  • 소규모의 라우팅 구조에 적용된 기존 그룹키 관리 구조는 항상 키 분배에 따른 많은 부하를 갖는 문제점을 갖게 된다. 이에 본 논문에서는 소규모 라우팅 구조에 적합한 PIM-SM 라우팅을 이용하여, 안전한 멀티캐스트 통신이 가능한 그룹키 관리 구조를 제안한다. 제안한 방식은 멀티캐스트 통신 그룹을 RP단위의 부그룹으로 나누고, 각 RP에 부그룹 키 관리자를 부여하여 그룹키를 주고 받도록 한다. 이로서 송/수신자간에 보호채널이 설정되고, 그룹키에 따른 데이터 변환작업이 필요하지 않고 경로 변경에 따른 새로운 키 분배가 불필요하게 되어 데이터 전송시간이 단축되는 장점을 갖게 된다.

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혼합학습 프로그램이 간호대학생의 윤리적 가치관에 미치는 효과 (Effects of a Blended Learning Program on Ethical Values in Undergraduate Nursing Students)

  • 김상돌
    • 간호행정학회지
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    • 제20권5호
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    • pp.567-575
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    • 2014
  • Purpose: This study was performed to investigate the effects of a blended learning program on ethical values in undergraduate nursing students. Methods: This study was a one group pretest-posttest design. Seventy-one undergraduate nursing students who were taking a nursing ethics course at K University in S city were conveniently selected. The blended learning program was undertaken for 120 minutes one day weekly for 15 weeks. It consisted of case-based learning through an online method combined with problem-based learning offline. Scores for ethical value were measured using the ethical values scale. Results: The ethical values score increased significantly in the students after the blended learning (p=.004). Of the subgroup of ethical values human-life, relationship with collaborator, and nursing job scores increased significantly in students after the blended learning, respectively (p=.034; p<.001; p<.001), the score for area as relationship with nursing clients decreased significantly in the students after the blended learning (p<.001). Conclusion: The blended learning program was identified as an educational program which induces a positive effect on the development of ethical values in undergraduate nursing students, and in future it can be utilized in nursing ethics education.

Taxonomic Position of Korean Isolates of Rhizoctonia solani Based on RAPD and ITS Sequencing of Ribosomal DNA

  • Jeon, Young-Ah;Kim, Wan-Gyu;Kim, Dae-Ho;Kwon, Soon-Wo;Hong, Seung-Beom
    • The Plant Pathology Journal
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    • 제26권1호
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    • pp.83-89
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    • 2010
  • Taxonomic position of 46 Korean isolates of Rhizoctonia solani which were classified into nine intraspecific groups by anastomosis and cultural characteristics was analyzed by randomly amplified polymorphic DNA (RAPD) and sequence analyses of the internal transcribed spacer (ITS) regions of ribosomal DNA. All the isolates within each group showed highly similar band patterns in RAPD. The ITS regions of the isolates within the same groups showed a high level of sequence similarity above 96.0% whereas similarities among different groups were below 94.4%. When compared with several reference strains of R. solani from foreign countries, all the Korean isolates were clustered with the foreign isolates belonging to the same groups in the phylogenetic tree. All six Korean strains of AG-4 were identified as HG-1 out of 3 subgroup of AG-4. We discussed taxonomic position of Korean isolates of R. solani and showed that sequence analysis with ITS regions could be a rapid and useful method for identification of intraspecific group of R. solani.