• ETRI Journal
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• 제41권5호
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• pp.637-647
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• 2019

Separating highly correlated users can reduce the loss caused by spatial correlation (SC) in multiuser multiple-input multiple-output (MU-MIMO) systems. However, few accurate analyses of the loss caused by SC have been conducted. In this study, we define signal-to-interference-plus-noise ratio (SINR) loss to characterize it in multiuser multiple-input single-output (MU-MISO) systems, and use coefficient of correlation (CoC) to describe the SC between users. A formula is deduced to show the accurate relation between SINR loss and CoC. Based on this relation, we propose a user selection method that utilizes CoC to minimize the average SINR loss of users in massive MU-MISO systems. Simulation results verify the correctness of the relation and show that the proposed user selection method is very effective at reducing the loss caused by SC in massive MU-MISO systems.

• Communications for Statistical Applications and Methods
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• 제29권6호
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• pp.655-664
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• 2022

On the motivation by an integrative study of multi-omics data, we are interested in estimating the structure of the sparse cross correlation matrix of two high-dimensional random vectors. We rewrite the problem as a multiple testing problem and propose a new method to estimate the sparse structure of the cross correlation matrix. To do so, we test the correlation coefficients simultaneously and threshold the correlation coefficients by controlling FRD at a predetermined level α. Further, we apply the proposed method and an alternative adaptive thresholding procedure by Cai and Liu (2016) to the integrative analysis of the protein expression data (X) and the mRNA expression data (Y) in TCGA breast cancer cohort. By varying the FDR level α, we show that the new procedure is consistently more efficient in estimating the sparse structure of cross correlation matrix than the alternative one.

• 동아시아식생활학회지
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• 제16권1호
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• pp.1-12
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• 2006

This study examine the relationship between the intake of food conformable to each Sasang constitution and the recognition of irregular symptoms of health condition. The study subjects were 362 university students nationwide, classified by heir Sasang constitution. In terms of the intakes of conformable food and the symptom recognition, the number of multiple subjective symptoms tended to rise as the Soeum type digested the conformable food. As for the kinds of food, the Soyang type showed a significant positive correlation between the intake of cucumber namul and the symptoms of eyes and skin, but a negative correlation between the intake of Chongak Kimchi and the symptoms of the digestive system The Soeum type showed a significant positive correlation between multiple subjective symptoms and the intake of Gatkimchi, fernbrake namul, naeng-i soup, naeng-i namul, Korean leek Kimchi, crown daisy namul, and curled mallow soup, a significant positive correlation between the symptom recognition of the respiratory system and the intake of fried flatfish, and chicken gomtang but a negative correlation between the symptom recognition of the eye and skin and the intake of boiled eel. The Taeum type presented the a sigmificant positive correlation between multiple subjective symptoms and the intake of spaghetti, a positive correlation between the symptoms of the respiratory system and the intake of tuna salad, a positive correlation between the symptoms of the eye and skin and the intake of mafa tofu, spaghetti, and tuna salad, a negative correlation between the symptoms of the mouth and anus and the intake of codfish jiri, and a negative correlation between the symptoms of the respiratory system and the intake of tuna salad.

• 한국전산구조공학회논문집
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• 제33권6호
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• pp.401-409
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• 2020

확률론적 지진취약도 평가는 구조물 혹은 기기의 손상확률을 각 취약도 변수별 조합을 통해 이루어진다. 지진취약도로부터 구해지는 2개 이상 기기의 동시손상확률 계산은 기존에는 각 기기의 손상확률을 독립으로 가정해 왔다. 하지만 기기별 손상확률에 상관성이 있으며, 이를 평가한 결과 상관성에 따라 동시손상확률이 변화할 수 있는 결과를 보였다. 이 지진상관성을 무시하면 비보수적인 결과가 나오고 따라서 이를 고려해서 계산되어야 한다. 이 연구에서는 지진상관계수를 해석적으로 평가하기 위해 몇 가지 확률 변수를 선정하여 각 변수별로 혹은 통합하여 평가하고 그 차이를 비교했다. 그리고 단순화된 모델과, 복잡한 모델에 대한 상관계수 차이도 비교하였다. 이들 방법에 따른 상관계수의 결과와 차이를 분석했다. 그 결과 각 변수별로 평가하는 것과 통합하여 평가할 때 변수별 영향의 차이에 따라 상관성이 변화함을 확인하였고, 모델이 단순할수록 상관성이 높아짐을 확인하였다.

• 한국음향학회지
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• 제13권6호
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• pp.15-23
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• 1994

본 논문은 소음원이 여러개 존재할 때 다중입력 다중제어의 능동적응제어에 관한 연구이다. 다중채널 제어의 ANC(Active Noise Control)에 관한 현재까지의 연구는 소음원이 여러개 존재하는 경우, 적응필터의 입력신호사이에 상관이 없는 것으로 가정하고 연구되었다. 그러나 실제는 소음신호의 수신마이크로폰에서 제거하고자 하는 소음신호들 사이에 상관이 존재하며, 다수개의 소음원 신호를 독립적으로 검출하는 것이 곤란한 경우가 많고 여기에 관한 연구가 불충분하다. 본 연구에서는 적응필터의 입력신호간에 소음원의 상관을 제거하는 상관제거필터를 제안하였다. 제안한 상관제거 필터를 삽입하여 소음제거 시뮬레이션 결과, 혼합비율을 $b_{12}=0.95$일 때 상관을 제거한 경우가 약 2배 정도 빠른 수렴속도를 나타냈다.

• 한국정보통신학회논문지
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• 제16권4호
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• pp.730-736
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• 2012

의사난수열은 코드 분할 다중접속과 같은 무선통신에서 중요한 역할을 한다. 여러 사용자가 동시에 시스템에 접속할 때 충돌이 발생 할 수 있는데, 의사난수열의 낮은 상관관계는 그런 통신시스템에서 다중 접속 간섭을 최소화 할 수 있다. 본 논문에서는 Welch bound의 관점에서 최적의 상호 상관관계 함숫값을 갖는 $m$-수열, GMW 수열, Kasami 수열, No 수열 등을 모두 포함하는 낮은 상호 상관관계를 갖는 비선형 확장 이진 수열군을 제안한다. 그리고 제안한 수열의 상호상관관계를 분석한다.

• 한국지진공학회논문집
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• 제24권3호
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• pp.141-148
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• 2020

For the important safety system, two or more units of identical equipment or redundant components with similar function were installed to prevent abnormal failure. If the failure probability of such equipment is independent, this redundancy could increase the system safety remarkably. However, if the failure of each component is highly correlated by installing in a structure or experiencing an earthquake event, the expected redundancy effect will decrease. Therefore, the seismic correlation of the equipment should be evaluated quantitatively for the seismic probabilistic safety assessment. The correlation effect can be explained in the procedure of constructing fragility curves. In this study, several methodologies to quantify the seismic correlation in the failure probability calculation for multiple components were reviewed and two possible ways considering the realistic situation were selected. Simple examples were tested to check the applicability of these methods. The conversion method between these two methods was suggested to render the evaluation using the advantages of each method possible.

• Journal of Korean Neurosurgical Society
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• 제29권5호
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• pp.628-634
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• 2000

Objective : The introduction of MRI makes it easy to detect multiple lumbar disc herniation. However, MRI is not a physiologic test for detecting the symptomatic level. For the surgical plan, it is very important to determine the symtomatic level among the multiple lumbar disc herniation. In this regard, we studied diagnostic significance of discography on multiple lumbar disc herniation in determining the symptomatic level. Method and Material : We retrospectvely analyzed the discographic and clinical findings of 121 patients with multiple lumbar disc herniation for investigating the diagnostic availability of discography. All were surgically treated from January 1995 through May 1998. Result : Discography provocated the same pain as usual symptom in 99 out of 121 patients(81.8%). Compared with surgical findings, the diagnostic accuracy of the discography in multiple lumbar disc herniation was 75.6%, sensitivity was 64.6%, and specificity 87.2%. There was no correlation between the pain provocation of discography and the extent of annular degeneration on CT/discogram. The pain provocation showed good correlation with the extent of annular disruption on CT/discogram. The rate of same result(correlation rate) between the discography and D.I.T.I was 81.4% in multiple lumbar disc herniation patients with unilateral leg pain. Conclusion : These results indicate that in multiple lumbar disc herniation, the discography is considered useful diagnostic tool to determine the symptomatic level and to decide the surgical plan.

• 아동학회지
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• 제25권4호
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• pp.115-128
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• 2004

In this study, we examined the relationship among Multiple Intelligence constructs and the relationship among the sub-areas and analysed the development of the Multiple Intelligence according to age and gender to evaluate Korean children's Multiple Intelligence structures that teachers evaluated based on MIDAS-MYC. The subjects of the study consisted of 158 4-5 year old children (71 4-year-old group(boy 38, girl 33); 87 5-year-old group(boy 40, girl 47)) in Seoul and Gyeonggi. We found several results which are as follows. 1) Reliability on each area of intelligence in MIDAS-MYC was good. 2) The result of confirmatory factor analysis using the model of structural equation modeling was consistent with the results of other studies that children's Multiple Intelligence consists of eight intelligent areas that are independent to each other but are relative to each other. In particular, interpersonal-intrapersonal intelligence, languistic-intrapersonal intelligence, languistic-Interpersonal intelligence, and languistic-logic/math intelligence were high correlation. However, physical/motion-naturalist intelligence and musical-logic/math intelligence were low correlation. 3) Children's multiple intelligence differed according to age and sex, the 5-year-old was higher than 4-year-old and girls were higher than boys in a general way. 4) There was high correlation between the result of evaluation based on MIDAS-MYC and the result of teacher's subjective evaluation about children's Multiple Intelligence.

• 한국치위생학회지
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• 제15권4호
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• pp.623-629
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• 2015

Objectives: The purpose of the study is to investigate the relationships between multiple intelligence, academic self-efficacy, satisfaction with major in dental hygiene students. Methods: A self-reported questionnaire was filled out by 490 dental hygiene students in Jeonbuk from March to April, 2015. The questionnaire consisted of 119 questions of multiple intelligences, 28 questions of academic self-efficacy, 5 questions of satisfaction with major by Likert 5 scale. Data were analyzed by descriptive statistics, Pearson's correlation test, and stepwise multiple regression test using SPSS 18.0 program. Results: The students had the highest score in interpersonal intelligence(3.57) and the lowest in naturalist intelligence(2.66). There was a positive correlation between the multiple intelligences, academic self-efficacy and satisfaction with major(p<0.05). The impact of multiple intelligences on academic self-efficacy was influenced by logical-mathematical intelligence, intrapersonal intelligence, musical intelligence, bodily-kinesthetic intelligence, and linguistic intelligence(p<0.05). The variables that had an impact on multiple intelligences and satisfaction with major were interpersonal intelligence and intrapersonal intelligence(p<0.01). Conclusions: The development of multiple intelligences can enhance the satisfaction with the major, quality of education, academic self-efficacy in the dental hygiene students.