• Title/Summary/Keyword: complex variable

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Point Cloud-Based Spatial Environment Development for Near Real-Time Erection Simulation in Shipyards

  • Yeon-Jun Kim;SeungYeol Wang;Jaewon Jang;Bon-Yeong Park;Dong-Kun Lee;Daekyun Oh
    • Journal of Ocean Engineering and Technology
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    • v.37 no.6
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    • pp.247-255
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    • 2023
  • Interference and collisions often occur in the loading process at shipyards. Existing simulation methods focus primarily on resource processes and schedules, and there is a lack of real-time reflection in the complex and highly variable loading process. This study aims to develop a spatial environment incorporating real-time product data, such as hulls, and confirms its effectiveness by simulating various construction scenarios. As a method, a near real-time spatial environment based on broadband laser scanning was established, with the situation of loading heavy cargo assumed when converting an existing ship into an LNG dual-fuel propulsion ship. A case study simulation of near-real-time cargo loading processes was then conducted using Unity 3D to confirm the interference and collision risks within the spatial environment. The results indicated that interference occurred in structures previously not identified in the design data, and a collision occurred during the loading object erection phase. The simulation confirmed that the identification of interference and collision risks during the erection phase highlights the need for a relocation or removal process of potential hazards before erection takes place. An improved erection simulation that integrates near real-time data could effectively prevent interference and collision risks.

A comparison study of pathological features and drug efficacy between Drosophila models of C9orf72 ALS/FTD

  • Davin Lee;Hae Chan Jeong;Seung Yeol Kim;Jin Yong Chung;Seok Hwan Cho;Kyoung Ah Kim;Jae Ho Cho;Byung Su Ko;In Jun Cha;Chang Geon Chung;Eun Seon Kim;Sung Bae Lee
    • Molecules and Cells
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    • v.47 no.1
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    • pp.100005.1-100005.15
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    • 2024
  • Amyotrophic lateral sclerosis is a devastating neurodegenerative disease with a complex genetic basis, presenting both in familial and sporadic forms. The hexanucleotide (G4C2) repeat expansion in the C9orf72 gene, which triggers distinct pathogenic mechanisms, has been identified as a major contributor to familial and sporadic Amyotrophic lateral sclerosis cases. Animal models have proven pivotal in understanding these mechanisms; however, discrepancies between models due to variable transgene sequence, expression levels, and toxicity profiles complicate the translation of findings. Herein, we provide a systematic comparison of 7 publicly available Drosophila transgenes modeling the G4C2 expansion under uniform conditions, evaluating variations in their toxicity profiles. Further, we tested 3 previously characterized disease-modifying drugs in selected lines to uncover discrepancies among the tested strains. Our study not only deepens our understanding of the C9orf72 G4C2 mutations but also presents a framework for comparing constructs with minute structural differences. This work may be used to inform experimental designs to better model disease mechanisms and help guide the development of targeted interventions for neurodegenerative diseases, thus bridging the gap between model-based research and therapeutic application.

Exploring the variations of the pancreatic ductal system: a systematic review and meta-analysis of observational studies

  • Adil Asghar;Ravi Kant Narayan;Nagavalli Basavanna Pushpa;Apurba Patra;Kumar Satish Ravi;R. Shane Tubbs
    • Anatomy and Cell Biology
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    • v.57 no.1
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    • pp.31-44
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    • 2024
  • The exocrine part of the pancreas has a duct system called the pancreatic ductal system (PDS). Its mechanism of development is complex, and any reorganization during early embryogenesis can give rise to anatomical variants. The aim of this study is to collect, classify, and analyze published evidence on the importance of anatomical variants of the PDS, addressing gaps in our understanding of such variations. The MEDLINE, Web of Science, Embase, and Google Scholar databases were searched to identify publications relevant to this review. R studio with meta-package was used for data extraction, risk of bias estimation, and statistical analysis. A total of 64 studies out of 1,778 proved suitable for this review and metanalysis. The meta-analysis computed the prevalence of normal variants of the PDS (92% of 10,514 subjects). Type 3 variants and "descending" subtypes of the main pancreatic duct (MPD) predominated in the pooled samples. The mean lengths of the MPD and accessory pancreatic duct (APD) were 16.53 cm and 3.36 cm, respectively. The mean diameters of the MPD at the head and the APD were 3.43 mm and 1.69 mm, respectively. The APD was present in only 41% of samples, and the long type predominated. The pancreatic ductal anatomy is highly variable, and the incorrect identification of variants may be challenging for surgeons during ductal anastomosis with gut, failure to which may often cause ductal obstruction or pseudocysts formation.

Assessing the repeatability of reflection seismic data in the presence of complex near-surface conditions CO2CRC Otway Project, Victoria, Australia (복잡한 천부구조하에서 반사법 탄성파자료의 반복성에 대한 평가, 호주, 빅토리아, CO2CRC Otway 프로젝트)

  • Al-Jabri, Yousuf;Urosevic, Milovan
    • Geophysics and Geophysical Exploration
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    • v.13 no.1
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    • pp.24-30
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    • 2010
  • This study utilises repeated numerical tests to understand the effects of variable near-surface conditions on time-lapse seismic surveys. The numerical tests were aimed at reproducing the significant scattering observed in field experiments conducted at the Naylor site in the Otway Basin for the purpose of $CO_2$ sequestration. In particular, the variation of elastic properties of both the top soil and the deeper rugose clay/limestone interface as a function of varying water saturation were investigated. Such tests simulate the measurements conducted in dry and wet seasons and to evaluate the contribution of these seasonal variations to seismic measurements in terms of non-repeatability. Full elastic pre-stack modelling experiments were carried out to quantify these effects and evaluate their individual contributions. The results show that the relatively simple scattering effects of the corrugated near-surface clay/limestone interface can have a profound effect on time-lapse surveys. The experiments also show that the changes in top soil saturation could potentially affect seismic signature even more than the corrugated deeper surface. Overall agreement between numerically predicted and in situ measured normalised root-mean-square (NRMS) differences between repeated (time-lapse) 2D seismic surveys warrant further investigation. Future field studies will include in situ measurements of the elastic properties of the weathered zone through the use of 'micro Vertical Seismic Profiling (VSP)' arrays and very dense refraction surveys. The results of this work may impact on other areas not associated with $CO_2$ sequestration, such as imaging oil production over areas where producing fields suffer from a karstic topography, such as in the Middle East and Australia.

A Systematic Approach to Producing Oral Records (체계적인 구술기록 생산을 위한 제언)

  • Sohn, Dong You;Kwon, Yong Chan
    • Journal of Korean Society of Archives and Records Management
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    • v.13 no.1
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    • pp.135-158
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    • 2013
  • While academic discussions and methodological researches on oral history are being progressed in Korea, its exploitation has already begun to increase with a variety of methods and approaches in the private sector. Oral history is a new method of research, as well as another process of production of archives. In order to make valuable and highly qualified archives of oral history with the application of the aforementioned conditions and characteristics, its recognition, environment, process, and method should be improved and developed. From this point of view, it is regarded as reasonable that oral history is recognized as a part of the strategy for documentation. Oral history should be produced based on common sense and reasonable judgment, applying empirical know-how rather than logic or principles because it holds a great number of characteristics, which include variable elements in the field of oral history. In addition, its process or documentation methods should be improved and developed, giving consideration to thorough exploitation. The promotion or revitalization of oral history is a signal that announces the advent of new archives and the new subjects of history at the same time. Endeavors to produce highly efficient archives of oral history are expected to be continued with the complex accumulation of empirical assets achieved at academic discussions and its fields.

Self-Efficacy as a Predictor of Self-Care in Persons with Diabetes Mellitus: Meta-Analysis

  • Lee, Hyang-Yeon
    • Journal of Korean Academy of Nursing
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    • v.29 no.5
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    • pp.1087-1102
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    • 1999
  • Diabetes mellitus, a universal and prevalent chronic disease, is projected to be one of the most formidable worldwide health problems in the 21st century. For those living with diabetes, there is a need for self-care skills to manage a complex medical regimen. Self-efficacy which refers to one's belief in his/her capability to monitor and perform the daily activities required to manage diabetes has be found to be related to self-care. The concept of self-efficacy comes from social cognitive theory which maintains that cognitive mechanism mediate the performance of behavior. The literature cites several research studies which show a strong relationship between self-efficacy and self-care behavior. Meta-analysis is a technique that enables systematic review and quantitative integration of the results from multiple primary studies that are relevant to a particular research question. Therefore, this study was done using meta-analysis to quantitatively integrate the results of independent research studies to obtain numerical estimates of the overall effect of a self-efficacy with diabetic patient on self-care behaviors. The research proceeded in three stages : 1) literature search and retrieval of studies in which self-efficacy was related to self-care, 2) coding, and 3) calculation of mean effect size and data analysis. Seventeen studies which met the research criteria included study population of adults with diabetes, measures of self-care and measures of self-efficacy as a predictive variable. Computation of effect size was done on DSTAT which is a statistical computer program specifically designed for meta-analysis. To determine the effect of self-efficacy on self-care practice homogeneity tests were conducted. Pooled effect size estimates, to determine the best subvariable for composite variables, metabolic control variables and component of self-efficacy and self-care, indicated that the effect of self-efficacy composite on self-care composite was moderate to large. The weighted mean effect size of self-efficacy composite and self-care composite were +.76 and the confidence interval was from +.66 to +.86 with the number of subjects being 1,545. The total for this meta-analysis result showed that the weighted mean effect sizes ranged from +.70 to +1.81 which indicates a large effect. But since reliabilities of the instruments in the primary studies were low or not stated, caution must be applied in unconditionally accepting the results from these effect sizes. Meta-analysis is a useful took for clarifying the status of knowledge development and guiding decision making about future research and this study confirmed that there is a relationship between self-efficacy and self-care in patients with diabetes. It, thus, provides support for nurses to promote self-efficacy in their patients. While most of the studies included in this meta-analysis used social cognitive theory as a framework for the study, some studies use Fishbein & Ajzen's attitude model as a model for active self-care. Future research is needed to more fully define the concept of self-care and to determine what it is that makes patients feel competent in their self-care activities. The results of this study showed that self-efficacy can promote self-care. Future research is needed with experimental design to determine nursing interventions that will increase self-efficacy.

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A Frequency Domain DV-to-MPEG-2 Transcoding (DV에서 MPEG-2로의 주파수 영역 변환 부호화)

  • Kim, Do-Nyeon;Yun, Beom-Sik;Choe, Yun-Sik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.2
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    • pp.138-148
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    • 2001
  • Digital Video (DV) coding standards for digital video cassette recorder are based mainly on DCT and variable length coding. DV has low hardware complexity but high compressed bit rate of about 26 Mb/s. Thus, it is necessary to encode video with low complex video coding at the studios and then transcode compressed video into MPEG-2 for video-on-demand system. Because these coding methods exploit DCT, transcoding in the DCT domain can reduce computational complexity by excluding duplicated procedures. In transcoding DV into MPEC-2 intra coding, multiplying matrix by transformed data is used for 4:1:1-to-4:2:2 chroma format conversion and the conversion from 2-4-8 to 8-8 DCT mode, and therefore enables parallel processing. Variance of sub block for MPEG-2 rate control is computed completely in the DCT domain. These are verified through experiments. We estimate motion hierarchically using DCT coefficients for transcoding into MPEG-2 inter coding. First, we estimate motion of a macro block (MB) only with 4 DC values of 4 sub blocks and then estimate motion with 16-point MB using IDCT of 2$\times$2 low frequencies in each sub block, and finish estimation at a sub pixel as the fifth step. ME with overlapped search range shows better PSNR performance than ME without overlapping.

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Study about the relationship between the amount of posterior impaction and the change of occlusal plane angle and incisor inclination in Le Fort I osteotomy (Le Fort I 골절단술에서 posterior impaction의 양과 occlusal plane angle, incisor inclination의 변화 관계에 관한 연구)

  • Kim, Bok-Joo;Kim, Min-Gu;Kim, Jung-Han;Kim, Chul-Hoon
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.36 no.5
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    • pp.375-379
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    • 2010
  • Introduction: In the management of dentofacial deformities, variable movement of the maxilla can be made possible by a Le Fort I osteotomy. Posterior impaction of the maxilla necessary for rotation of the maxillomandibular complex enhances the functions and esthetic results. In cases of posterior impaction of the maxilla, an increase in the figure of the occlusal plane angle and incisor inclination can occur. This study reports the relationship between the amount of posterior impaction and the change in the occlusal plane angle and incisor inclination in a Le Fort I osteotomy by preoperative and postoperative lateral cephalograms. Materials and Methods: Twenty patients who had undergone orthognathic surgery in Dong-A University Medical Center participated in this study. Lateral cephalometrics, within 3 weeks prior to surgery and 3 days after surgery, were used for analysis. Pre and postoperative measurements of the occlusal plane angle and incisal inclination based on the Frankfort horizontal (FH) plane were performed. X and Y were defined as the amount of vertical change in the upper incisor tip and the amount of vertical change in the upper first molar mesial cup tip through the operation. The amount of final posterior maxillary impaction was determined by subtracting Y from X, which is the difference in vertical height. According to the amount of posterior maxillary impaction, the change in the occlusal plane angle and incisal inclination was measured. Results: The average posterior maxillary impaction was 2.91 mm and the average change in the occlusal plane angle and incisal inclination was $6.54^{\circ}$after surgery. As a result, each mm of posterior maxillary impaction changed the occlusal plane angle and incisal inclination by $2.25^{\circ}$. Statistically, there was high significance. Two cases were observed: one with the same amount of posterior maxillary impaction performed on both the right and left showing $2.20^{\circ}$, and the other with a different amount of posterior maxillary impaction performed showing $2.35^{\circ}$. In this case, there was no significance difference between the two cases. Conclusion: Each mm of posterior maxillary impaction changes the occlusal plane angle and incisal inclination by an average of $2.25^{\circ}$. In posterior maxillary impaction, there was no significant difference in the amount of change in the occlusal plane angle and incisal inclination regardless of whether there was an equal amount of posterior maxillary impaction on both sides. This study is expected to help in the presurgical orthodontic preparation and presurgical treatment planning.

Use of Beam Transmissometer as an Indirect Measure of Suspended Sediment Concentration in the Estuarine Environment: Application and Problems (강하구에서의 부유물질농도 결정을 위한 광전도측정기의 이용 및 문제점)

  • KIM Seok-Yun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.6
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    • pp.771-781
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    • 1994
  • Monthly measurements made at 15 stations along the axis of the upper Neuse River estuary show a highly variable degree of correlation between concentration of suspended particulate material (SPM) and attenuation coefficient (c) of light as measured by transmissometer. Coefficients of determination along transect lines ranged from $0.12{\sim}0.93$ and calibration slopes ranged from $0.50{\sim}5.63$. When examined on a station-by-station basis, coefficients of determination ranged from $0.21{\sim}0.96$ and calibration slopes ranged from $1.04{\sim}4.94$. Surface calibrations made at individual stations over the full 13-month period were the most consistent of all observations and were considerably better than calibrations made using all of the stations on a given day. Organic content, which can dominate the suspended sediment load during some months, does not appear to explain the variations in reliability of the calibrations. However, an abundance of large aggregates with time-varying size and shape distributions may be partly responsible for variations in optical properties of the sediments, and thus may confound the relationship between SPM and c in the Neuse River estuary Time-varying calibrations to account for non-negligible changes in optical properties may not suffice in complex estuarine environments where the in situ particle dynamics are poorly understood. However, the best use of Beam Transmissometer will continue to be for applications such as detecting water-column events or for use in situations where wide error bars in establishing SPM concentrations are acceptable.

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The relationship between stress and suicidal ideation among the Korean Multi-Cultural family Adolescents (한국 다문화가정 청소년의 스트레스와 자살생각과의 관련성)

  • Park, Hyung-Su;Yu, Jin-Ho;Park, Bu-Yeon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.5
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    • pp.771-777
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    • 2013
  • This study was investigated the relationship between the stress and suicidal ideation of adolescents from multi-cultural families. For the purpose, the study incorporated data of Youth Risk Behavior Web-based Survey 2011-2 and attempted to understand factors of their suicide ideation and reasons of stress, targeting 607 boy students and 543 girl students. For a statistical analysis, SPSS version 17.0 was used. During the analysis, the students one of which parents was not born in Korea were considered as those from multi-cultural families and statistical significance was set to be p<0.05, To look into relations between suicide ideation and reasons of stress with the former as a subordinate variable, the study figured out Odds Ratio(OR) through a simple logistics analysis and a complex sample was set for the analysis. Boy students had 2.70 times more suicide ideation due to stress from associates than girl students while girl students had 2.50 times more suicide ideation due to conflicts with parents than boy students. In conclusion, as there were various reasons of stress relating to individuals, families and school life which may affect suicide ideation of adolescents from multi-cultural families, our society should pay attention especially to improvement of relationships with parents and friends to prevent and control their suicide ideation.