• International Area Studies Review
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• v.20 no.1
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• pp.209-234
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• 2016

This study examines the effects of exporter agglomeration on purely local firms' decision to undertake internationalization and the resultant performance enhancement from internationalization using propensity score matching and difference-in-differences approach. We find that the likelihood of starting to export is higher when purely local firms are located in a region with a higher level of exporter agglomeration, as positive externalities allow them to overcome insufficient internal resources and reduce the large initial foreign market entry costs. We also find that newly exporting firms are more likely to experience greater performance enhancement from exporting when they are locate in a region with a lower level of exporter agglomeration.

• Asia Marketing Journal
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• v.22 no.1
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• pp.1-26
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• 2020

Firms employing hierarchical loyalty programs (HLPs) periodically demote customers from higher to lower status level to divest from unprofitable customers and boost profitability. However, existing literature lacks objective evidence on how customer demotion affects demoted customers' future purchase behaviors and ultimately profitability for the firm. Moreover, customers in the HLP's higher position may respond to customer demotion differently from those in the HLP's lower position. Drawing upon emotions and equity theories, this study quantifies how the profits that customers contribute to the firm change after customer demotion, and compares demoted customers' behavioral reactions from top-tier with those from bottom-tier based on customers' actual behavior data from a major retail bank in South Korea. The findings show that withdrawing customer status actually deteriorates customer profitability, and customers with top-tier status decrease their profitability more dramatically than those with bottom-tier status after demotion. The results contribute to previous literature on customer demotion and relationship marketing, and provide specific guidelines into how firms should design and implement customer demotion in HLPs.

• Journal of Korea Trade
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• v.26 no.3
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• pp.102-116
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• 2022

Purpose - This paper empirically investigates the relationship between firm productivity and importing intermediate inputs in the Korean manufacturing sector. Design/methodology - This paper tests the two related hypotheses on the relationship between importing and productivity for a sample of Korean manufacturing firms. We test the self-selection hypothesis by comparing pre-entry levels of productivity between importers and non-importers. We test the learning-by-importing hypothesis by employing propensity score matching with differencein-differences approach. Findings - Future importers are more productive than future non-importers years before they start to import, which supports the self-selection hypothesis. In contrast, there is no strong evidence for learning-by-importing. Originality/value - This paper is the first study to explore the relationship between importing and firm-level productivity for Korean firms. The results have an important implication on trade policies to lower or raise trade barriers in imported inputs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.8
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• pp.2137-2156
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• 2024

Customer reviews are the second-most reliable source of information, followed by family and friend referrals. However, there are many existing customer reviews. Some online shopping platforms address this issue by ranking customer reviews according to their usefulness. However, we propose an alternative method to rank customer reviews, given that this system is easily manipulable. This study aims to create a ranking model for reviews based on their usefulness by combining product and seller service aspects from customer reviews. This methodology consists of six primary steps: data collection and preprocessing, aspect extraction and sentiment analysis, followed by constructing a regression model using random forest regression, and the review ranking process. The results demonstrate that the ranking model with service considerations outperformed the model without service considerations. This demonstrates the model's superiority in the three tests, which include a comparison of the regression results, the aggregate helpfulness ratio, and the matching score.

• Journal of Korean Academy of Nursing
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• v.23 no.1
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• pp.107-117
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• 1993

This study was a clinical Quasi-experiment to examine the effects of the range of motion exercise on powerlessness and life satisfaction among the E-Institutionalized elderly in Pusan. The purpose was to test the effect of the range of motion exercises on powerlessness and life satis-faction, and to examine the correlation between powerlessness and life satisfaction. The subjects for this study were 54 elderly people, both were over 60 and residing at I-Institution in Pusan. The research samples of 54 elderly were divided into an experimental and control group by matching randomized assignment. The instruments for this study were the Assessment Tool of Powerlessness in the elderly developed by Miller, Life satisfaction developed by Yoon Jin, and the Active-Passive Range of Motion Exercise Program which was developed and utilized by Shin, Jae-Shin. The data were collected from December 15, 1990 to November 1991. The paired t-test, t-test and ANCOVA were used to test hypothesis I and II, related to the Effect of the Range of Motion Exercises to powerlessness and life satisfaction. To identify the relationship of the range of motion exercises to powerlessness and life satisfaction, path analysis was done through multiple regression. The interrelationship of the variables was analyzed using t-test paired t-test. The results of the three hypothesis can be summarized as follows : 1. Hypothesis I -the experimental group which participated in the Range of Motion Exercise gets lower powerlessness score than that of the control group-was accepted by t-test (t = -3.40, p = .001) but not accepted by ANCOVA (F = .1, p =.96). 2. Hypothesis II - the experimental group which participated in the Range of Motion Exercise gets a higher Life Satisfaction Score than that of the control group-was not supported by t-test(t = 1.01, p = .316) but was accepted by ANCOVA (F = 4.39, p = .006). 3. Hypothesis III - if the powerlessness Score becomes higher, the Life Satisfaction Score will be-come lower - was accepted by Pearson Correlation Coefficient (pre-exercise : r : -.34, p=.006), (post exercise : r = -.06, p=.32) . The relation-ship between the score of powerlessness and life satisfaction was negatively correlated. The results obtained clearly showed that the effects of the range of motion exercises on powerlessness and life satisfaction are beneficial to the elderly The relation between the scores of powerlessness and life satisfaction was negatively correlated and the range of motion exercise had a direct influence to powerlessness. Therefore, it is concluded that the relationship between powerlessness and life satis-faction was not a causal one. Also it is concluded that the range of motion exercises can be applied as a nursing intervention to reduce powerlessness and to improve life satisfaction in the elderly.

• Journal of Korean Clinical Nursing Research
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• v.24 no.2
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• pp.170-177
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• 2018

Purpose: The aim of this study was to examine effectiveness of 12-hour shifts for nurses compared to 8-hour shifts for the variables: Work-Life Balance, fatigue and work errors. Methods: In 2014, an opportunity to choose a 12-hour shift duty was given to a group of 8-hour shift nurses. In 2016, two years after this change, this study was done to compare the two groups. Data were collected using questionnaires. Data were sampled by a matching method with propensity score matching (PSM). The participants were 128 nurses: 64 nurses on 12-hour shifts and 64 nurses on 8-hour shifts. The comparison was analyzed using $x^2$ test, t-test. Results: The nurses on 12-hour shifts showed higher scores for Work-Life Balance (3.37) than the groups on 8-hour shifts (2.99)(p=.018) whereas were no statistical differences between the groups for fatigue (p=.132) or work errors (p=.703). Conclusion: The Work-Life Balance scores for nurses who chose the 12-hour shift shows an enhancement without an increase in fatigue or work errors.

• The Journal of Korean Medicine
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• v.43 no.3
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• pp.65-78
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• 2022

Objectives: The purpose of this study is to analyze the weight loss and the adverse events of overweight and obese adults on weight loss program with face-to-face treatment (FTF) and non-face-to-face treatment (NFTF) in 6 Korean Medicine obesity clinics. Methods: From March 2nd to March 10th, 2021, we collected data with a retrospective way from overweight and obese adults (body mass index, BMI≥23 kg/m²) who registered for a 12-week Gamitaeeumjowi-tang prescription program. After matching initial information of the FTF group and the NFTF group using propensity matching score, weight loss and BMI change were analyzed, and adverse events were evaluated in terms of causality, severity and system-organ classes. Results: Weight and BMI change from baseline to 12 weeks was -7.98±3.09kg (10.41±3.57%), -3.03±1.14kg/m² and -7.30±3.11kg (9.59±3.45%), -2.76±1.15kg/m² for FTF group and NFTF group, respectively. Body weight and BMI significantly decreased before and after treatment in both groups, and there was no significant difference in weight loss and BMI change between the two groups. No serious adverse events were reported. Conclusions: This study showed the potential that NFTF weight management treatment could be a good alternative way to FTF weight management treatment without serious adverse events.

• Journal of Society of Preventive Korean Medicine
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• v.28 no.1
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• pp.69-87
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• 2024

Objectives : This study is to investigate the current National Health Insurance Database cohort studies related to complications of Parkinson's Disease (PD) and suggest the design of Korean medical epidemiological studies of PD. Methods : Nationwide longitudinal studies of PD patients in South Korea were collected through Pubmed and the Korea Citation Index (KCI). We selected cohort studies that used the National Health Insurance Database in Korea and targeted Parkinson's disease patients. Studies published before February 2024 were categorized according to study designs. We examined variables and covariates, enroll dates and matching methods. Results : Of a total of 536 studies, 18 studies met the inclusion criteria. All studies used the National Health Insurance (NHI) Research Database and among them, 5 used sample data and one senior database. Studies can be classified into two types. 11 cohort studies were comparing PD patients and non-PD patients. Another type was 4 PD patients cohort studies. Most studies used two diagnostic codes (G20 and V124) for inclusion criteria. Enroll periods were from 2002 to 2017, and follow-up periods were from 7 to 14 years. 16 studies considered age and sex as covariates. 15 studies used the propensity score matching method to increase the level of causality. There was only one study related to the Korean medical treatment. Conclusion : In future cohort studies on Korean medical treatment, more attempts should be made to reveal the effect of the treatments on PD patients by defining inclusion criteria for patient groups, covariates, exposure variables, and assessment indicators more operatively.

• Journal of Information Science Theory and Practice
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• v.12 no.3
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• pp.49-62
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• 2024

Strategy monitoring is essential for business management and for administrators, including managers and executives, to build a data-driven organization. Having a tool that is able to visualize strategic data is significant for business intelligence. Unfortunately, there are gaps between business users and information technology departments or business intelligence experts that need to be filled to meet user requirements. For example, business users want to be self-reliant when using business intelligence systems, but they are too inexperienced to deal with the technical difficulties of the business intelligence systems. This research aims to create an automatic matching framework between the key performance indicators (KPI) formula and the data in database systems, based on ontology concepts, in the case study of Prince of Songkla University. The mapping data schema with ontology (MapDSOnto) framework is created through knowledge adaptation from the literature review and is evaluated using sample data from the case study. String similarity methods are compared to find the best fit for this framework. The research results reveal that the "fuzz.token_set_ratio" method is suitable for this study, with a 91.50 similarity score. The two main algorithms, database schema mapping and domain schema mapping, present the process of the MapDS-Onto framework using the "fuzz.token_set_ratio" method and database structure ontology to match the correct data of each factor in the KPI formula. The MapDS-Onto framework contributes to increasing self-reliance by reducing the amount of database knowledge that business users need to use semantic business intelligence.

• Journal of Chest Surgery
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• v.50 no.5
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• pp.339-345
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• 2017

Background: In recent years, single-port video-assisted thoracoscopic surgery (VATS) for lobectomy in non-small cell lung cancer (NSCLC) patients has become increasingly common. The objective of this study was to compare the feasibility and safety of single-port and triple-port VATS lobectomy. Methods: A total of 73 patients with NSCLC who underwent VATS lobectomy from December 2011 to August 2016 were retrospectively reviewed, including 47 in the triple-port group and 26 in the single-port group. Statistical analysis was performed after propensity score matching. Patients were matched on a 1-to-1 basis. Results: Operative time and intraoperative blood loss in the triple-port group and the single-port group were similar ($189.4{\pm}50.8minutes$ vs. $205.4{\pm}50.6minutes$, p=0.259; $286.5{\pm}531.0mL$ vs. $314.6{\pm}513.1mL$, p=0.813). There were no cases of morbidity or mortality. No significant differences in complications or the total number of dissected lymph nodes were found between the 2 groups. In the single-port group, more mediastinal lymph nodes were dissected than in the triple-port group ($1.7{\pm}0.6$ vs. $1.2{\pm}0.5$, p=0.011). Both groups had 1 patient with bronchopleural fistula. Chest tube duration and postoperative hospital stay were shorter in the single-port group than in the triple-port group ($8.7{\pm}5.1days$ vs. $6.2{\pm}6.6days$, p=0.130; $11.7{\pm}6.1days$ vs. $9.5{\pm}6.4days$, p=0.226). However, the differences were not statistically significant. In the single-port group, the rate of conversion to multi-port VATS lobectomy was 11.5% (3 of 26). The rates of conversion to open thoracotomy in the triple-port and single-port groups were 7.7% and 3.8%, respectively (p=1.000). Conclusion: In comparison with the triple-port group, single-port VATS lobectomy showed similar results in safety and efficacy, indicating that single-port VATS lobectomy is a feasible and safe option for lung cancer patients.