• Nuclear Engineering and Technology
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• 제53권12호
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• pp.4080-4092
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• 2021

In this study, the performance of sequence tracking methods for multiple interaction events in specific CdZnTe Compton imagers was evaluated using Monte Carlo simulations. The Compton imager consisted of a 6 × 6 array of virtual Frisch-grid CZT crystals, where the dimensions of each crystal were 5 × 5 × 12 mm³. The sequence tracking methods for another Compton imager that consists of two identical CZT crystals arrays were also evaluated. When 662 keV radiation was incident on the detectors, the percentages of the correct sequences determined by the simple comparison and deterministic methods for two sequential interactions were identical (~80%), while those evaluated using the minimum squared difference method (55-59%) and Three Compton method (45-55%) for three sequential interactions, differed from each other. The reconstructed images of a 662 keV point source detected using single and double arrays were evaluated based on their angular resolution and signal-to-noise ratio, and the results showed that the double arrays outperformed single arrays.

• 천문학회보
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• 제36권2호
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• pp.84.1-84.1
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• 2011

In this study, we intend to inquire of how the temporal variation and spatial distribution of magnetic helicity injection in a CME-producing solar active region are related to the CME occurrence. We therefore investigate long-term (a few days) variation of magnetic helicity injection in the active region NOAA 9236 which produced multiple CME events. As a result, it is found that a noticeable increase in helicity of negative sign was first made for the first ~1.5 days and then 6 CMEs occurred while the relatively more injection of oppositely signed (positive) helicity was taking place for the next ~2 days. Afterwards, 2 CMEs in the region occurred while a more negative helicity is being injected again compared to a positive helicity. In addition, from helicity flux density maps, we found that the CMEs originated from this active region seem to be involved with the interaction of two magnetic field systems characterized by opposite signs of helicity.

• 대한가정학회지
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• 제34권3호
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• pp.305-325
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• 1996

This study was designed to compare mothers' beliefs of literacy development and home literacy environment and to explore how the children interacted with their mother during literacy activities and how they used the strategies to develop knowledge of literacy. The qualitative data was collected from multiple sources of naturalistic information and analyzed through triangulation of diverse methods including participant observations in the home, parental during literacy events, written logs kept by the mothers, the children's writing products, three emergent assessment forms, and photographs. The three preschoolers and their mothers provided different literacy experiences to support their children's emerging conventional literacy development. Child 1's mother highly valued the rich home literacy environment and the child 1's initiative interactions during literacy events. Child 3's home literacy context was very similar to her Montessori classroom's phonic approach and writing skills. Child 2 was provided with an inappropriate literacy environment at home through direct instruction and an emphasis on correct writing. All of the children were interested and attended to story. Child 1 interacted with her mother in expanded cycles as child's initiation, mother's clarification, and child's evaluation, compared with the child 2's simple cycle and the child 3's classroom-like cycle as mother's initiation, child's response, and mother's evaluation. The children and their mothers employed a number of diverse strategies to understand knowledge of literacy. Importantly parent education needs to emphasize the importance of playful one to one mother-child interaction, a functional holistic literacy environment., and strategies for expanding child's knowledge with parent as mediator.

• 산업기술연구
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• 제18권
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• pp.225-232
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• 1998

Train crashes involve complex interaction between deformable bodies in multiple collisions. The purpose of this study is to suggest the effective analytical procedure using finite element model for the crashworthiness of motorized trailer of high speed train. Various types of crash events are investigated and the conditions for numerical simulation are defined. Finally korean high speed train which consists of aluminum members can be analyzed and designed by the numerical simulation.

• Biomedical Engineering Letters
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• 제8권4호
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• pp.383-392
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• 2018

For prompt gamma ray imaging for biomedical applications and environmental radiation monitoring, we propose herein a multiple-scattering Compton camera (MSCC). MSCC consists of three or more semiconductor layers with good energy resolution, and has potential for simultaneous detection and differentiation of multiple radio-isotopes based on the measured energies, as well as three-dimensional (3D) imaging of the radio-isotope distribution. In this study, we developed an analytic simulator and a 3D image generator for a MSCC, including the physical models of the radiation source emission and detection processes that can be utilized for geometry and performance prediction prior to the construction of a real system. The analytic simulator for a MSCC records coincidence detections of successive interactions in multiple detector layers. In the successive interaction processes, the emission direction of the incident gamma ray, the scattering angle, and the changed traveling path after the Compton scattering interaction in each detector, were determined by a conical surface uniform random number generator (RNG), and by a Klein-Nishina RNG. The 3D image generator has two functions: the recovery of the initial source energy spectrum and the 3D spatial distribution of the source. We evaluated the analytic simulator and image generator with two different energetic point radiation sources (Cs-137 and Co-60) and with an MSCC comprising three detector layers. The recovered initial energies of the incident radiations were well differentiated from the generated MSCC events. Correspondingly, we could obtain a multi-tracer image that combined the two differentiated images. The developed analytic simulator in this study emulated the randomness of the detection process of a multiple-scattering Compton camera, including the inherent degradation factors of the detectors, such as the limited spatial and energy resolutions. The Doppler-broadening effect owing to the momentum distribution of electrons in Compton scattering was not considered in the detection process because most interested isotopes for biomedical and environmental applications have high energies that are less sensitive to Doppler broadening. The analytic simulator and image generator for MSCC can be utilized to determine the optimal geometrical parameters, such as the distances between detectors and detector size, thus affecting the imaging performance of the Compton camera prior to the development of a real system.

• 한국임상약학회지
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• 제32권3호
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• pp.204-214
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• 2022

Objective: This study aimed to investigate the occurrence and types of the adverse events (AEs) associated with oral fluconazole and itraconazole and factors associated with specific types of AEs. Methods: We analyzed AEs reported by community pharmacies nationwide over 10 years using the Korea Adverse Event Reporting System database. Various AE terms were categorized into 18 types, and concomitant medications were classified by drug-drug interaction (DDI) severity. The relationship between the specific type of AE and age, sex, and number of concomitant medications was investigated using multiple logistic regression analysis. Results: A total of 879 AE reports of fluconazole and 401 reports of itraconazole were analyzed; of these reports, 321 and 83 reports of fluconazole and itraconazole, respectively, described concomitant drug administration categorized as DDI severity of contraindicated or major. Women had a higher risk of psychiatric AEs associated with fluconazole use (OR, 1.587; p=0.042). Polypharmacy increased the risk for psychiatric AEs (OR, 3.598; p<0.001 for fluconazole and OR, 2.308; p=0.046 for itraconazole). In dermatologic AEs, the mean age of patients who received itraconazole was lower than that of patients who received fluconazole (46.3±16.8 vs. 54.9±15.4; p<0.001). Co-administration of fluconazole with 1-3 drugs increased the risk of neurological AEs (OR, 1.764; p=0.028). Conclusion: When using fluconazole and itraconazole, psychiatric AEs should be noted, particularly in women and in case of polypharmacy; moreover, when fluconazole is co-administered with other drugs, attention should be paid to the occurrence of neurological AEs.

• 아태비즈니스연구
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• 제14권4호
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• pp.289-303
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• 2023

Purpose - The purpose of this study is to investigate the types and forms of various marketing activities actually used in pharmaceutical companies and to empirically analyze the impact of these marketing activities on sales. Design/methodology/approach - This study categorize five years' worth of marketing activity data from a foreign pharmaceutical company 'A' which operates in South Korea into five categories. Multiple regression analysis and interaction effects are employed for data analysis. Findings - First, CRM calls, Detail calls, GP, and Web events have a positive impact on sales, but SoV does not show significant differences. Second, in the comparison between HQ1 and HQ2 based on patent ownership, Detail calls and Web events had a stronger impact on sales in HQ2, where the patent period is still in effect, compared to HQ1. However, SoV showed no difference between HQ1 and HQ2. Research implications or Originality - First, Detail Calls are more effective for drugs with active patents, while CRM Calls work better for drugs with expired patents. This emphasizes the need to customize call strategies based on patent status. Second, the significant impact of Web Events on sales in HQ2 compared to HQ1 suggests that online information access is crucial, indicating that customer receptivity varies based on product nature. Third, these insights, derived from data analysis, call for a shift in pharmaceutical marketing analysis methods away from traditional approaches. Finally, this study holds significance as one of the first empirical analyses using actual marketing data from pharmaceutical companies in South Korea.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.867-872
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• 2016

Background: Esophageal cancer is one of the most serious malignancies. Due to the aggressive nature of this cancer, the prognosis is poor. A network meta-analysis with simultaneous comparison of multiple treatments can help determine better treatment options that have higher effects on overall survival of patients with lower adverse events. The aim of this review is to simultaneously compare efficacy and adverse events of treatment interventions for esophageal cancer. Materials and Methods: In this review, only randomized control trials (RCT) will be considered for network meta-analysis. All international electronic databases including Medline, Web of Sciences, Scopus, Cochran's library, EMBASE and Cancerlit will be searched to find randomized control trials which compared two or more treatment interventions for esophageal cancer. A network plot will be drawn for visual representation of all available treatment interventions. Bayesian approach will be used to combine the direct and indirect evidence. Treatment effects (e.g. hazard ratio for time to event outcomes, risk ratio for binary outcomes, and rate ratio for count outcomes with 95% credible interval) will be reported. Moreover, cumulative probability of the treatment ranks will be reported using the surface under the cumulative ranking (SUCRA) graphs. Consistency assumption will be assessed by the loop-specific and design-by-treatment interaction approaches. Conclusions: The results of this study may be helpful for the patients, clinicians and health policy makers in selecting treatments that have the best effect on survival and lowest adverse events.

• 인터넷정보학회논문지
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• 제16권4호
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• pp.25-37
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• 2015

본 연구에서는 모바일 환경에서 사용자가 원하는 마커 위에 2D 이미지, 3D 모델, 동영상과 같은 가상객체를 증강시키고 인터랙션 이벤트를 연결시켜 주는 모바일 증강현실 콘텐츠 빌더(MARB ; Moblie AR contents Builder, 이하 MARB)를 개발하였다. MARB은 사용자가 원하는 마커 위에 다양한 가상객체를 증강시켜주며, 마커에 따른 여러 인터랙션 이벤트를 선택적으로 제공한다. 또한 모바일 환경에서 간편하게 구동하기 위해 모바일 콘텐츠 형태로 개발되었으며, 모바일기기에 설치하면 간단한 GUI(Graphical User Interface)를 이용한 저작이 가능하다. MARB은 기존 개발자뿐만 아니라 일반 사용자가 모바일 콘텐츠를 자유롭게 저작할 수 있도록 하여 다양한 모바일 증강현실 콘텐츠를 원하는 사용자들에 의해 다방면적으로 활용될 것으로 기대되며, 모바일 증강현실 시장 확장에 걸림돌이 되고 있는 모바일 증강현실 콘텐츠 개발의 어려움을 극복하는데 기여할 것으로 예상된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.198-204
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• 2001

Train crashes involve complex interaction between deformable bodies in multiple collisions. The purpose of this study is to suggest the effective analytical procedure using hybrid model for the crashworthiness of motorized trailer of high speed train. The hybrid approach, with very short modeling times and reduced computation times to extract the global behaviour and to perform a pre-optimization of the considered structure. Firstly, various types of crash events are investigated and the conditions for numerical simulation are defined. In this paper, the structural crashwonhiness of Korean High Speed Train trailer was examined through FE analysis. Crash analyses on energy absorbing part and safety zone were carried out to determine each section force. Rollover analysis was performed to observe the amount of intrusion in the passenger's area in case of rollover accident.