• Korean Circulation Journal
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• 제52권9호
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• pp.699-711
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• 2022

Background and Objectives: We investigated whether extra-pulmonary vein (PV) ablation targeting a high maximal slope of the action potential duration restitution curve (Smax) improves the rhythm outcome of persistent atrial fibrillation (PeAF) ablation. Methods: In this open-label, multi-center, randomized, and controlled trial, 178 PeAF patients were randomized with 1:1 ratio to computational modeling-guided virtual Smax ablation (V-Smax) or empirical ablation (E-ABL) groups. Smax maps were generated by computational modeling based on atrial substrate maps acquired during clinical procedures in sinus rhythm. Smax maps were generated during the clinical PV isolation (PVI). The V-Smax group underwent an additional extra-PV ablation after PVI targeting the virtual high Smax sites. Results: After a mean follow-up period of 12.3±5.2 months, the clinical recurrence rates (25.6% vs. 23.9% in the V-Smax and the E-ABL group, p=0.880) or recurrence appearing as atrial tachycardia (11.1% vs. 5.7%, p=0.169) did not differ between the 2 groups. The post-ablation cardioversion rate was higher in the V-Smax group than E-ABL group (14.4% vs. 5.7%, p=0.027). Among antiarrhythmic drug-free patients (n=129), the AF freedom rate was 78.7% in the V-Smax group and 80.9% in the E-ABL group (p=0.776). The total procedure time was longer in the V-Smax group (p=0.008), but no significant difference was found in the major complication rates (p=0.497) between the groups. Conclusions: Unlike a dominant frequency ablation, the computational modeling-guided V-Smax ablation did not improve the rhythm outcome of the PeAF ablation and had a longer procedure time.

• 대한인간공학회지
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• 제36권2호
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• pp.87-108
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• 2017

Objective: The purpose of this study was to precede the acceptance study based on automation steps and user experience that was lacked in the past study on the core technology of autonomous vehicle, ADAS. The first objective was to construct the acceptance model of ADAS technology that is the core technology, and draw factors that affect behavioral intention through user experience-based evaluation by applying driving simulator. The second one was to see the change of factors on automation step of autonomous vehicle through the UX/UA score. Background: The number of vehicles with the introduction of ADAS is increasing, and it caused change of interaction between vehicle and driver as automation is being developed on the particular drive factor. For this reason, it is becoming important to study the technology acceptance on how driver can actively accept giving up some parts of automated drive operation and handing over the authority to vehicle. Method: We organized the study model and items through literature investigation and the scenario according to the 4 stages of automation of autonomous vehicle, and preceded acceptance assessment using driving simulator. Total 68 men and woman were participated in this experiment. Results: We drew results of Performance Expectancy (PE), Social Influence (SI), Perceived Safety (PS), Anxiety (AX), Trust (T) and Affective Satisfaction (AS) as the factors that affect Behavioral Intention (BI). Also the drawn factors shows that UX/UA score has a significant difference statistically according to the automation steps of autonomous vehicle, and UX/UA tends to move up until the stage 2 of automation, and at stage 3 it goes down to the lowest level, and it increases a little or stays steady at stage 4. Conclusion and Application: First, we presented the acceptance model of ADAS that is the core technology of autonomous vehicle, and it could be the basis of the future acceptance study of the ADAS technology as it verifies through user experience-based assessment using driving simulator. Second, it could be helpful to the appropriate ADAS development in the future as drawing the change of factors and predicting the acceptance level according to the automation stages of autonomous vehicle through UX/UA score, and it could also grasp and avoid the problem that affect the acceptance level. It is possible to use these study results as tools to test validity of function before ADAS offering company launches the products. Also it will help to prevent the problems that could be caused when applying the autonomous vehicle technology, and to establish technology that is easily acceptable for drivers, so it will improve safety and convenience of drivers.

• 한국토양비료학회지
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• 제36권4호
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• pp.210-217
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• 2003

산화물에 대한 카드뮴의 흡착특성을 모사하기 위하여 토양에 존재하는 대표적 산화광물인 침철광과 석영을 대상으로 회분형 카드뮴 흡착실험을 수행하였다. 토양 광물에 대한 카드뮴의 흡착을 예측하기 위해 기존의 경험적 흡착모델 대신 표면착물 모델을 적용하였다. 모델을 검증하기 위하여 카드뮴의 흡착에 영향을 미치는 pH, 중금속 농도, 산화물 농도 및 이온강도 등의 인자를 조절하며, 다양한 조건하에서 회분형 흡착실험을 수행하였다. 실험결과, 카드뮴의 농도가 증가함에 따라 pH에 따른 흡착 곡선은 알칼리 쪽으로 평행하게 이동하였다. 흡착 실험으로부터 계산한 50%의 카드뮴이 흡착되는 pH인 $pH_{50}$은 합성 침철광이 5.25로 석영의 7.83에 비해 매우 낮아 카드뮴에 대한 표면 결합력이 석영에 비해 합성 침철광이 우세함을 시사하였고 이는 모델의 모사 결과와도 잘 부합하였다. 또한 배경전해질로 사용한 $KNO_3$의 이온강도는 카드뮴의 흡착에 영향을 미치지 않았다. 따라서 카드뮴은 산화광물 표면에 내부이온흡착 메커니즘에 의하여 흡착되는 것으로 판단할 수 있었다.

• Journal of Ecology and Environment
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• 제44권1호
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• pp.33-40
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• 2020

Background: Understanding the geographical distribution of a species is a key component of studying its ecology, evolution, and conservation. Although Schlegel's Japanese gecko (Gekko japonicus) is widely distributed in Northeast Asia, its distribution has not been studied in detail. We predicted the present and future distribution of G. japonicus across China, Japan, and Korea based on 19 climatic and 5 environmental variables using the maximum entropy (MaxEnt) species distribution model. Results: Present time major suitable habitats for G. japonicus, having greater than 0.55 probability of presence (threshold based on the average predicted probability of the presence records), are located at coastal and inland cities of China; western, southern, and northern coasts of Kyushu and Honshu in Japan; and southern coastal cities of Korea. Japan contained 69.3% of the suitable habitats, followed by China (27.1%) and Korea (4.2%). Temperature seasonality (66.5% of permutation importance) was the most important predictor of the distribution. Future distributions according to two climate change scenarios predicted that by 2070, and overall suitable habitats would decrease compared to the present habitats by 18.4% (scenario RCP 4.5) and 10.4% (scenario RCP 8.5). In contrast to these overall trends, range expansions are expected in inland areas of China and southern parts of Korea. Conclusions: Suitable habitats predicted for G. japonicus are currently located in coastal cities of Japan, China, and Korea, as well as in isolated patches of inland China. Due to climate change, suitable habitats are expected to shrink along coastlines, particularly at the coastal-edge of climate change zones. Overall, our results provide essential distribution range information for future ecological studies of G. japonicus across its distribution range.

• Asian Pacific Journal of Cancer Prevention
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• 제17권2호
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• pp.661-665
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• 2016

Background: Stomach cancer is the fifth most common cancer and the third leading cause of death among cancers throughout the world. Therefore, stomach cancer outcomes can affect health systems at the national and international levels. Although stomach cancer mortality and incidence rates have decreased in developed countries, these indicators have a raising trend in East Asian developing countries, particularity in Iran. In this study, we aimed to determine the time trend of age-standardized rates of stomach cancer in different districts of Iran from 2000 to 2010. Materials and Methods: Cases of cancer were registered using a pathology-based system during 2000-2007 and with a population-based system since 2008 in Iran. In this study, we collected information about the incidence of stomach cancer during a 10 year period for 31 provinces and 376 districts, with a total of 49,917 cases. We employed two statistical approaches (a random effects and a random effects Markov model) for modeling the incidence of stomach cancer in different districts of Iran during the studied period. Results: The random effects model showed that the incidence rate of stomach cancer among males and females had an increasing trend and it increased by 2.38 and 0.87 persons every year, respectively. However, after adjusting for previous responses, the random effects Markov model showed an increasing rate of 1.53 and 0.75 for males and females, respectively. Conclusions: This study revealed that there are significant differences between different areas of Iran in terms of age-standardized incidence rates of stomach cancer. Our study suggests that a random effects Markov model can adjust for effects of previous responses.

• 유통과학연구
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• 제13권11호
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• pp.47-58
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• 2015

Purpose - This study aims to seek determinants of department store sales commission rates under consignment contracts based on transaction cost theory, the power-dependence view, and the resource-based view. A consignment contract is a unique contract where the retailer, over a given period, takes possession of goods owned by a supplier, promotes the sales of these goods, and receives a profit share from their sales. Under this contract, the supplier owns the goods until they are sold. In department stores in South Korea, over 70% of overall sales comes through consignment contracts. In other words, this is the most popular contract agreement between large retailers and vendors in South Korea. Consignment contracts yield high profits to department stores with minimal sales uncertainty, stock cost, and marketing investment. Many suppliers believe the consignment contract commission rates are too high. However, department stores disagree. They state that the commissions are not high as they generate new value for the suppliers by accumulating up-to-date merchandise and supporting various marketing programs on their behalf. Recently, consignment contracts have been critically examined and scrutinized by politicians, mass media, and the public of Korea. This study further intends to derive implications reflecting both buyer and seller perspectives as well as offer insights to policy makers in making appropriate decisions. Research design, data, and methodology - To verify the proposed research model and test hypotheses, the authors selected 164 suppliers, which currently have relationships with department stores. This study carefully investigated the reliability, content validity, convergent validity, and discriminant validity of the proposed model. The data were analyzed using SPSS 18.0 and AMOS structural equation modeling program Results - For the transaction cost theory and the power-dependence view, the results indicated that product diversity and demand volatility had a positive impact on the sales dependence on a department store. Dependence in turn had a positive effect on the sales commission under the consignment contract. Based on the resource-based view, the department store's marketing capability, the supplier's perception toward merchandising, and supporting activities could enhance the department store's channel leadership in the buyer-seller relationship. Subsequently, the channel leadership had a positive effect on the sales commission. However, product complexity had no relationship with department store dependence. Conclusions - This is the first empirical research that investigates the determinants of sales commissions under consignment contracts in the domestic retail industry. This study reveals several theoretical and practical implications for both marketing scholars and marketers. In terms of theoretical implication, this study integrated and enlarged certain theoretical background, such as transaction cost theory, the power-dependence view, and the resource-based view, to explain the determinants of sales commissions under consignment contracts that include sales revenue. From a business management viewpoint, this research offers useful insights for policy makers by applying two different perspectives, both the manufacturer and the retailer, in terms of the sales commission issue under a consignment contract.

• Nutrition Research and Practice
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• 제14권3호
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• pp.218-229
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• 2020

BACKGROUND/OBJECTIVES: Type 2 Diabetes mellitus (T2DM) is a hereditary disease that is also strongly dependent on environmental factors, lifestyles, and dietary habits. This study explored the relationship between lifestyle habits and glycosylated hemoglobin management in T2DM patients to provide empirical outcomes to improve T2DM management and patient health literacy. SUBJECTS/METHODS: This study enrolled 349 diabetic patients with more than 5 care visits to a Diabetes Mellitus care network under the Health Management Plan led by Taiwan Department of Health (DOH). Based on relevant literature, an Outpatient Record Form of Diabetes Mellitus Care was designed and lipid profile tests were conducted for data collection and analysis. RESULTS: When modeling the data, the results showed that the odds for HbA1c > 7.5% in T2DM patients duration over 10 years was 3.785 (P = 0.002) times that in patients with disease duration of fewer than 3 years. The odds of HbA1c > 7.5% in illiterate patients was 3.128 (P = 0.039) times that in patients with senior high school education or above. The odds of HbA1c > 7.5% in patients with other chronic illness was 2.207 (P = 0.019) times that in participants without chronic illness. Among 5 beneficial lifestyle habits, the odds of HbA1c > 7.5% in patients with 2 or 3 good habits were 3.243 (P = 0.003) and 3.424 (P = 0.001) times that in patients with more than 3 good habits, respectively. CONCLUSION: This empirical outcome shows that maintaining a good lifestyle improves T2DM management and patients' knowledge, motivation, and ability to use health information. Patients with longer disease duration, education, or good lifestyle habits had optimal HbA1c management than those in patients who did not. Thus, effective selfmanagement and precaution in daily life and improved health literacy of diabetic patients are necessary to increase the quality of T2DM care.

• 대한인간공학회지
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• 제34권3호
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• pp.279-291
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• 2015

Objective: The purpose of the study is to evaluate appropriate weight for aged farmers in manually handling livestock feed in bags using ergonomic methods. Background: In the livestock industry in South Korea, despite the trend of aging of labor manpower, heavy items are still manually handled in many farms. In particular, among stockbreeding works, the handling of feed in bags weighing 25~30kg is reported as a cause of frequent injuries and musculoskeletal system diseases. However, studies on the standard for recommended weight allowed considering the physical characteristics of aged farmers older than 60 years with greatly decreased physical strength and muscle strength are insufficient. Method: To evaluate appropriate weight for handling of heavy livestock feed in bags, physical techniques for measuring recognized levels of physical work loads, the NLE (NIOSH lifting equation) a method that is an observation type technique, and an ergonomic modeling technique to predict compressive force imposed on L5/S1 were used. Subjects who participated in the experiment were organized into two groups of males/females with mean age exceeding 60 years, and lifting tasks were evaluated for nine weight levels. Results: Based on the results of psychophysical measurement, females showed a tendency of more drastic increases compared to males when weight was over 19kg. The results of estimation of regression models for the weight, 18.0 kg ($r^2=0.97$) and 15.3kg ($r^2=0.97$) were evaluated as stable load for males and females, respectively. In addition, both the observation type evaluation and ergonomic model evaluation showed stable loads in a range of 15~18kg. Conclusion: Given the results of the study, the weight of the feed in bags currently distributed to farms can become a cause of not only overexertion but also farm work related disasters such as musculoskeletal disorders and safety accidents. Providing livestock feed in bags weighing not more than 19kg for aged farmers is judged desirable, and managerial improvement for this matter is considered necessary. Application: The results of the present study can be utilized as useful data for institutional improvement of the weight of livestock feed in bags.

• 대한방사성의약품학회지
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• 제2권2호
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• pp.108-112
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• 2016

Molecular imaging with the radiolabeled RGD peptides for ${\alpha}_v{\beta}_3$ integrin has been an increasing interest for tumor diagnosis and the treatment monitoring. Recently, $^{64}Cu$-NODAGA-gluco-E[c(RGDfK)]$_2$ was developed for quantification of ${\alpha}_v{\beta}_3$ integrin and its biological properties was elucidated. To better understand the molecular process in vivo, we performed the kinetic analysis for the $^{64}Cu$-NODAGA-gluco-E[c(RGDfK)]$_2$. After preparation of a radiotracer, dynamic PET images were obtained in the U87MG xenograft mice for 60 min (n = 6). Binding potential values were estimated from the 3-tissue compartment model, reference Logan and simplified reference tissue model. In the early time frame (0-20 min), the liver, kidney, intestine, urinary bladder and tumor were visualized but these uptakes were diminished as time went by. The tumors showed a good contrast at 40 min after administration. $^{64}Cu$-NODAGA-gluco-E[c(RGDfK)]$_2$ showed the 2-fold uptake in the tumor compared with that in the muscle. The parametric maps for binding values also provide the higher tumor-to-background contrast than the static images. A binding value obtained from the 3-tissue compartment model was comparable to other modeling methods. From these results, we conclude that $^{64}Cu$-NODAGA-gluco-E[c(RGDfK)]$_2$ may be a promising PET radiotracer for the evaluation of angiogenesis.

• IMMUNE NETWORK
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• 제12권2호
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• pp.58-65
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• 2012

Background: A cell line with transfected Wilms' tumor protein 1 (WT1) is has been used for the preclinical evaluation of novel treatment strategies of WT1 immunotherapy for leukemia due to the lack of appropriate murine leukemia cell line with endogenous WT1. However, silencing of the transgene occurs. Regarding the effects of hypomethylating agents (HMAs) on reactivation of silenced genes, HMAs are considered to be immune enhancers. Methods: We treated murine WT1- transfected C1498 (mWT1-C1498) with increasing doses of decitabine (DAC) and azacitidine (AZA) to analyze their effects on transgene reactivation. Results: DAC and AZA decreased the number of viable cells in a dose- or time-dependent manner. Quantification of WT1 mRNA level was analyzed by real-time polymerase chain reaction after mWT1-C1498 treated with increasing dose of HMA. DAC treatment for 48 h induced 1.4-, 14.6-, and 15.5-fold increment of WT1 mRNA level, compared to untreated sample, at 0.1, 1, and $10{\mu}M$, respectively. Further increment of WT1 expression in the presence of 1 and $10{\mu}M$ DAC was evident at 72 h. AZA treatment also induced up-regulation of mRNA, but not to the same degree as with DAC treatment. The correlation between the incremental increases in WT1 mRNA by DAC was confirmed by Western blot and concomitant down-regulation of WT1 promoter methylation was revealed. Conclusion: The in vitro data show that HMA can induce reactivation of WT1 transgene and that DAC is more effective, at least in mWT1-C1498 cells, which suggests that the combination of DAC and mWT1-C1498 can be used for the development of the experimental model of HMA-combined WT1 immunotherapy targeting leukemia.