• Journal of Information Processing Systems
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• 제16권3호
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• pp.530-540
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• 2020

In order to solve the problem of low tracking accuracy caused by complex noise in the fault diagnosis of complex nonlinear system, a fault diagnosis method of high precision cost reference particle filter (CRPF) is proposed. By optimizing the low confidence particles to replace the resampling process, this paper improved the problem of sample impoverishment caused by the sample updating based on risk and cost of CRPF algorithm. This paper attempts to improve the accuracy of state estimation from the essential level of obtaining samples. Then, we study the correlation between the current observation value and the prior state. By adjusting the density variance of state transitions adaptively, the adaptive ability of the algorithm to the complex noises can be enhanced, which is expected to improve the accuracy of fault state tracking. Through the simulation analysis of a fuel unit fault diagnosis, the results show that the accuracy of the algorithm has been improved obviously under the background of complex noise.

• 지역사회간호학회지
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• 제32권1호
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• pp.73-85
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• 2021

Purpose: The purpose of this qualitative study is to explore the adaptation process of correctional officers' job stress. Methods: Participants collected were fourteen officers who had experienced the adaptation process of job stress. Data were collected through individual in-depth interviews until the point of theoretical saturation from May to August, 2017. Transcribed interview contents were analyzed using Corbin and Strauss' grounded theory method. Results: A total of 98 concepts, 27 subcategories, and 10 categories were identified through the open coding. As a result of axial coding based on the paradigm model, the job stress adaptation process centering phenomenon of correctional officers was revealed as 'repeat-mark hardening', and the core category was extracted as 'endurance in hardening' consisting of a three-step process: enduring, understanding prisoner management procedures, and rebuilding. The rebuilding was considered as the key phase to escape the repeat-mark hardening and the participants utilized various strategies such as finding fun elsewhere, restoring confidence, accepting values of the prison officer in this phase. Conclusion: The results of this study suggest that the adaptation process of correctional officers' job stress can be a process that endurance the hardening. Therefore, it is necessary to develop systematic practical education and vocational motivation programs.

• Communications for Statistical Applications and Methods
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• 제30권2호
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• pp.163-178
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• 2023

GARCH-X(1, 1) model specifies that conditional variance follows an AR(1) process and includes a past exogenous variable. This study proposes a new class from that model by allowing a more general (non-linear) variance function to follow an AR(1) process. The functions applied to the variance equation include exponential, Tukey's ladder, and Yeo-Johnson transformations. In the framework of normal and student-t distributions for return errors, the empirical analysis focuses on two stock indices data in developed countries (FTSE100 and SP500) over the daily period from January 2000 to December 2020. This study uses 10-minute realized volatility as the exogenous component. The parameters of considered models are estimated using the adaptive random walk metropolis method in the Monte Carlo Markov chain algorithm and implemented in the Matlab program. The 95% highest posterior density intervals show that the three transformations are significant for the GARCHX(1, 1) model. In general, based on the Akaike information criterion, the GARCH-X(1, 1) model that has return errors with student-t distribution and variance transformed by Tukey's ladder function provides the best data fit. In forecasting value-at-risk with the 95% confidence level, the Christoffersen's independence test suggest that non-linear models is the most suitable for modeling return data, especially model with the Tukey's ladder transformation.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제34권4호
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• pp.258-267
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• 2023

Objectives: This study aimed to compare the utility of the Psychoeducational Profile-Revised (PEP-R), Korean Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (K-WPPSI-IV), and Vineland Adaptive Behavior Scale, Second Edition (VABS-II) for evaluating developmental disabilities (DD) in preschool children. Additionally, we examined the correlations between the PEP-R, K-WPPSI-IV, and VABS-II. Methods: A total of 164 children aged 37-84 months were assessed. Children's development was evaluated using the PEP-R, K-WPPSI-IV, VABS-II, Preschool Receptive-Expressive Language Scale, and Korean Childhood Autism Rating Scale, Second Edition. Results: Of the 164 children, 103 had typical development (TD) and 61 had DD. The mean of the PEP-R Developmental Quotient (DQ), K-WPPSI-IV Full-Scale Intelligence Quotient (FSIQ), and VABS-II Adaptive Behavior Composite (ABC) scores were significantly higher in the TD group than in the DD group (p<0.001). The estimated area under the curve of the PEP-R DQ, K-WPPSI-IV FSIQ, and VABS-II ABC scores was 0.953 (95% confidence interval [CI]=0.915-0.992), 0.955 (95% CI=0.914-0.996), and 0.961 (95% CI=0.932-0.991), respectively, which did not indicate a statistically significant difference. The PEP-R DQ scores were positively correlated with the K-WPPSI-IV FSIQ (r=0.90, p<0.001) and VABS-II ABC scores (r=0.84, p<0.001). A strong correlation was observed between the K-WPPSI-IV FSIQ and VABS-II ABC scores (r=0.89, p<0.001). Conclusion: This study found that the PEP-R, K-WPPSI-IV, and VABS-II effectively distinguished DD from TD in preschool children, and no significant differences in utility were observed between them.

• Korean Journal of Radiology
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• 제22권5호
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• pp.688-698
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• 2021

Objective: To compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS). Materials and Methods: The Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods. Bland-Altman plots were used to evaluate the agreement between the measurements. Results: Lumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 mm³; 95% confidence interval [CI], 4.9-24.3 mm³); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, -0.7 mm³; 95% CI, -9.1-7.7 mm³). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 mm²; 95% CI, 0.89-1.25 mm²) but not in the larger lumen area group (mean of difference, -0.07 mm²; 95% CI, -0.22-0.08 mm²). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 mm²; 95% CI, 0.27-0.65 mm²) than in that of IVUS and SATM (1.53 mm²; 95% CI, 1.27-1.79 mm²). Conclusion: SATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM.

• 한국지진공학회논문집
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• 제6권4호
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• pp.65-73
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• 2002

성능에 기초한 설계법에서는 비선형 응답산정이 필수적이며, 이를 위한 방법으로는 비선형시각이력해석법, 비선형 정적해석법, 비선형 효과를 고려한 등가선형해석법 등이 있다. 일부 규준에서는 pushover곡선으로부터 작성한 성능스펙트럼과 선형 응답스펙트럼으로부터 작성한 요구스펙트럼으로 이루어진 능력스펙트럼법을 제안하고 있다. 이 방법은 개념적으로는 간단하나 반복과정이 요구되며, 부정확한 결과를 산출하는 경우가 많다. 이에 따라 시행착오적인 등가선형 스펙트럼대신 비선형스펙트럼을 사용하는 방법들에 대한 연구들이 진행되고 있다. 비선형 요구스펙트럼은 표준적 선형 설계스펙트럼으로부터 결정될 수 있으며, 이 방법은 등가선형의 경우보다는 계산과정이 대폭 줄어들기는 하나 아직도 다소의 연산과정이 요구된다. 따라서 본 연구에서는 다자유도계의 구조물에 대한 pushover곡선으로부터 구조물의 진동주기와 항복강도를 구한 다음, 일련의 계산과정을 거치지 않고도, 직접적으로 비선형 최대응답을 구할 수 있는 비선형 직접스펙트럼법(NDSM)을 제시하극 집중질량계의 MDF(다자유도계) 모델에 대해 다양한 지진기록과 제하강성저하지수를 변수로 하여 NDSM의 적용성과 신뢰성을 평가하고자 한다. 본 연구의 결론은 다음과 같다. 1) 다자유도계 구조물에 대한 비선형 직접스펙트럼법에 의한 최대변위 응답은 비선형 시각이력해석법에 의한 응답과 거의 일치하므로 실용적인 방법으로 사료된다. 2) 비선형 직접스펙트럼법과 비선형 시각이력해석에 의해 산정된 죄상층 변위 결과를 비교하면, 항복후강성계수가 0.1, MAD(modal adaptive distribution)에 의한 수평정적하중분폰 그리고 제하강성저하지수가 0.2~O.3일 때 평균오차가 가장 줄어드는 것으로 나타났다.

• 인지과학
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• 제20권3호
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• pp.357-381
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• 2009

이전의 연구들이 외부 피드백 정보에 대한 반응민감도에 성격특성적 개인차가 반영된다는 사실을 밝힌바 있지만, 재인기억과 관련한 의사결정에서 이러한 기질 혹은 특성적 개인차가 어떻게 관여하는지는 아직 알려진 바가 없다. 본 연구는 재인기억 과제에서 피드백에 근거한 의사결정 준거의 순응적 변화정도와 피드백에 대한 일반적 반응민감도의 개인차간 관계를 살펴보았다. 통제 조건인 실험 1에서는 올바른 피드백 조건이 의사결정 준거의 유동성에 영향을 미치지 않음을 보인 반면 피드백 조작이 이루어진 실험 2에서는 확신도가 높은 오기억 반응에만 선택적으로 편향된 피드백이 주어졌음에도 전반적인 Old/New 반응 범주의 결정준거 또한 순응적으로 이동함이 나타났다. 보다 중요하게 이 피드백에 근거한 의사결정 준거 학습에 나타나는 개별 피험자들의 반응민감도 차이가 강화 추구 혹은 불안 회피와 밀접하게 관련된 안정적 성격(Behavioral Activation System-BAS 혹은Behavioral Inhibition System-BIS)의 개인차에 의해 유의미하게 예측될 수 있음이 나타났다. 이러한 결과는 그동안 외현적인 재인 기억 의사 결정에 있어서 중요하게 여기지 않았던 점증적 강화학습 기제가 결정 준거의 설정에 관여할 수 있음을 보여준다는 데에서 중요한 의미를 찾을 수 있다.

• Genomics & Informatics
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• 제14권3호
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• pp.125-135
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• 2016

Helicobacter pylori is a Gram-negative bacteria that is responsible for gastritis in human. Its spiral flagellated body helps in locomotion and colonization in the host environment. It is capable of living in the highly acidic environment of the stomach with the help of acid adaptive genes. The genome of H. pylori 26695 strain contains 1,555 coding genes that encode 1,445 proteins. Out of these, 340 proteins are characterized as hypothetical proteins (HP). This study involves extensive analysis of the HPs using an established pipeline which comprises various bioinformatics tools and databases to find out probable functions of the HPs and identification of virulence factors. After extensive analysis of all the 340 HPs, we found that 104 HPs are showing characteristic similarities with the proteins with known functions. Thus, on the basis of such similarities, we assigned probable functions to 104 HPs with high confidence and precision. All the predicted HPs contain representative members of diverse functional classes of proteins such as enzymes, transporters, binding proteins, regulatory proteins, proteins involved in cellular processes and other proteins with miscellaneous functions. Therefore, we classified 104 HPs into aforementioned functional groups. During the virulence factors analysis of the HPs, we found 11 HPs are showing significant virulence. The identification of virulence proteins with the help their predicted functions may pave the way for drug target estimation and development of effective drug to counter the activity of that protein.

• Korean Journal of Radiology
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• 제24권1호
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• pp.51-61
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• 2023

Objective: To develop and test a machine learning model for classifying human papillomavirus (HPV) status of patients with oropharyngeal squamous cell carcinoma (OPSCC) using ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET-derived parameters in derived parameters and an appropriate combination of machine learning methods in patients with OPSCC. Materials and Methods: This retrospective study enrolled 126 patients (118 male; mean age, 60 years) with newly diagnosed, pathologically confirmed OPSCC, that underwent ¹⁸F-FDG PET-computed tomography (CT) between January 2012 and February 2020. Patients were randomly assigned to training and internal validation sets in a 7:3 ratio. An external test set of 19 patients (16 male; mean age, 65.3 years) was recruited sequentially from two other tertiary hospitals. Model 1 used only PET parameters, Model 2 used only clinical features, and Model 3 used both PET and clinical parameters. Multiple feature transforms, feature selection, oversampling, and training models are all investigated. The external test set was used to test the three models that performed best in the internal validation set. The values for area under the receiver operating characteristic curve (AUC) were compared between models. Results: In the external test set, ExtraTrees-based Model 3, which uses two PET-derived parameters and three clinical features, with a combination of MinMaxScaler, mutual information selection, and adaptive synthetic sampling approach, showed the best performance (AUC = 0.78; 95% confidence interval, 0.46-1). Model 3 outperformed Model 1 using PET parameters alone (AUC = 0.48, p = 0.047) and Model 2 using clinical parameters alone (AUC = 0.52, p = 0.142) in predicting HPV status. Conclusion: Using oversampling and mutual information selection, an ExtraTree-based HPV status classifier was developed by combining metabolic parameters derived from ¹⁸F-FDG PET/CT and clinical parameters in OPSCC, which exhibited higher performance than the models using either PET or clinical parameters alone.

• 초등상담연구
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• 제5권1호
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• pp.227-253
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• 2006

It seems common for students living at a small county and islands to experience psychological conflicts and be unaccustomed in the peer society because they are not familiar with peer interaction and social skills. This is a case study of L (hereinafter called L) who was grown up in the sheltered school at a small county. L was psychologically disturbed because he couldn't get along well in the transferred school. It is the reason why he had lived in the sheltered school at a small county, so he had not enough exposure to interact with peer and social skills. Sometimes he was obstinate irrationally and when he had trouble with friends, he threw something out or went out of school and tricked juniors dangerously. The fact of disperse with families, parent's indifference, and hate of older brother made L to have ill feeling against family. He had low motivation and low self confident in learning because of short attention time and accumulated poor learning progress. In this study, he was evaluated at various area, such as, intelligent, affective, personal and inter-personal, before counselling. To evaluated the effect of the counselling, K-WISC-III, KPRC, sentence filling test, social adaptation ability test, etc, were administered right after the counselling was over and 8 weeks later. For specific information gathering and analysing, observation diary and deepen counselling were accomplished by homeroom teacher, his mother, and his peers. To correct his problematic behaviors, 13 counseling sessions were accomplished for 6 months and those counselling sessions were recorded and analysed definitely. Followings are the result of this case study. First, he was recovered from the anxiety of inter-personal interaction and he started to interact with peers. The result of sac scale score of KPRC profile was lower than before as much as average student after counseling and 8 weeks later. This reveals that the distress against interpersonal relation have settled. Especially, through the result of sentence filing test, he seemed to feel attachment to peers and be positive, active in the relation of peer. For instance, he was active in the open class lesson and interacted well with peers. It could be said that he overcame the psychological distress comparing with previous time. Second, he could apologize to his peer and juniors for his fault. His attitude were well shown in the letter from an old friend at the sheltered school, average KPRC profiling score comparing with previous counseling time, and remarkable decrease of attack scale score of teacher and peer. Third, his view toward family turn out positive. He recognized his situation that he lived apart from family and even worried about his parent's financial difficulty. Through solving the confliction with his older brother, he could acquire the feeling of family reunion. Fourth, his learning motivation and self-confidence were increased. He confirmed his future positively and he might be judged more attentive because his intelligence index was higher than before as much as average student. With the main goal of this study, verification for effectiveness of counseling. understanding and helping problematic students such as L who lives at a small county and island through investigation of their real situation and problems with the method of counseling and socio-cultural analysis is worthwhile. Identification of ideal relationship with peer is related with positive self-conception, harmonic social adaptation and development of child. It is time to investigate easy adaptive in classroom and well-organised program to acquire general social skills for sheltered school students at a small county and islands.