• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.5
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• pp.43-59
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• 2019

The promotion of social economy is one of the Korean government's top 100 initiatives. As of August 2019, there are 2,249 certified social enterprises in Korea, showing explosive growth with a 41-fold increase from 2007 when the Social Enterprise Promotion Act was first enacted. Currently, the discussion of the sustainability of social-economic organizations is lively, including the issue of changing the certification system to the registration system. Noting the unusual management structure of social enterprise - seeking both social and economic value, this study identifies factors affecting the performance of social enterprises. The study focuses on an empirical investigation of the relationships between characteristics of entrepreneurs' experiences in social economy, strategic competency, the extent to which they seek social value, and their performance. This study is unique in social enterprise research due to its approach to the hybrid management structure of social enterprise with a focus on entrepreneurs' characteristics. Accordingly, this empirical investigation focuses on how social-value seeking mediates the relationships between strategic competency emphasized in typical for-profit enterprises, the characteristics of experiences stressed in social-economic organizations, and the performance of social enterprises. The study findings suggest that, firstly, social entrepreneurs must seek social value as a top priority and improve economic performance using strategic competency to keep pursuing social value, and secondly, social-value seeking must be founded upon entrepreneurs' understanding and experiences in social economy. Practical implications of the study findings include concrete directions for training in social enterprises offered by relevant agencies and the establishment of competency models for current and future entrepreneurs.

• Journal of the Korean Geotechnical Society
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• v.37 no.5
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• pp.5-17
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• 2021

In this study, the shear behavior between pile-sandy soil interface was quantified based on series of rigorous ring shear test results. Ring shearing test was carried out to observe the shear behavior prior to failure and behavior at residual state between most commonly used pile materials - steel and concrete - and Jumunjin sand. The test was set to clarify the shear behavior under various confinement conditions and soil densities. The test results were converted in to representative friction angles for various test materials. Additional numerical analysis was executed to validate the accuracy of the test results. Based on the test results and the numerical validation, it was found that due to the dilative and contractive nature of sand, its interface behavior can be categorized in to two different types : soils with higher densities tend to show peak shear stress and moves on to residual state, while on the other hand, soils with lower densities tend to show bilinear load-transfer curves along the interface. However, the relative density and the confining stress was found to affect the friction angle only in the small train range, and converges as it progresses to large deformation. This study established a large deformation analysis method which can successfully simulate and predict the large deformation behavior such as ring shear tests. Moreover, the friction angle derived from the ring shear test result and verified by numerical analysis can be applied to numerical analysis and actual design of various pile foundations.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1175-1183
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• 2020

Purpose To evaluate the technical feasibility and clinical efficacy of percutaneous transgastric stent placement after the failure of treatment attempt with the transoral approach in malignant gastroduodenal obstruction patients. Materials and Methods From October 2008 to April 2016, nine patients (M:F = 4:5; mean age = 66 years) with malignant gastroduodenal obstruction underwent stent placement via a gastrostomy tract, which was attributed to the failure of the transoral approach. The primary etiologies of the obstruction were pancreatic (n = 5), gastric (n = 2), and metastatic (n = 2) cancers. Through percutaneous gastrostomy, dual stents (inner bare metal and outer polytetrafluoroethylene-covered) were deployed at the obstruction site. The technical and clinical success rates, as well as complications were evaluated during the follow-up period. Results Stents were successfully inserted in eight patients (88%). We failed to insert stent in one patient due to the presence of a tight obstruction. After stent placement, symptoms improved in seven patients. Gastrostomy tube was removed 9 to 20 days (mean = 12 days) after the stent insertion. During the mean follow-up of 136 days (range, 3-387 days), one patient developed a recurrent symptom due to tumor overgrowth. However, there were no other major complications associated with the procedure. Conclusion Percutaneous transgastric stent placement appeared to be technically feasible and clinically effective in patients who underwent a failed transoral approach.

• Journal of Labour Economics
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• v.24 no.3
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• pp.13-38
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• 2001

The question about whether a shorter workweek may increase employment has been a serious issue and been furiously debated among collective bargainers. The advocators recommend publicly that a reduction in standard working hours will provide benefits to the unemployed through the provision of new jobs, and also can improve the quality of life workers. The opponents argue that a shorter workweek will increase labor costs and induce firms to reduce their production levels, and consequently cut back their demand for labor. Although the debate is still continuing, considerable has been made toward achieving the goal workweek reduction. The analytical framework of this paper is a Putty-clay-model, in which the short-and long-term impacts of changes in working time on the employment associated with the interrelations of wages, prices, hourly labour productivity, the firm's labor demand, business cycle and economic growth etc. must be analyzed.

• Journal of the Korea Institute of Building Construction
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• v.22 no.6
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• pp.651-662
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• 2022

The electrochemical impedance spectroscopy(EIS) method was used to evaluate the concrete deterioration process related to chloride-induced steel corrosion with various corrosion levels(initiation, rust propagation and acceleration periods). The impressed current technique, with four total current levels of 0C, 13C, 65C and 130C, was used to accelerate steel corrosion in concrete cylinder samples with w/c ratio of 0.4, 0.5, and 0.6, immersed in a 0.5M NaCl solution. A series of EIS measurements was performed to monitor concrete deterioration during the accelerated corrosion test in this study. Some critical parameters of the equivalent circuit were obtained through the EIS analysis. It was observed that the charge transfer resistance(R_c) dropped sharply as the impressed current increased from 0C to 13C, indicating a value of approximately 10kΩcm². However, the sensitivity of R_c significantly decreased when the impressed current was further increased from 13C to 130C after corrosion of steel had been initiated. Meanwhile, the double-layer capacitance value(C_dl) linearly increased from 50×10^-6μF/cm² to 250×10^-6μF/cm² as the impressed current in creased from 0C to 130C. The results in this study showed that monitoring C_dl is an effective measurement parameter for evaluating the progress of internal concrete damages(de-bonding between steel and concrete, micro-cracks, and surface-breaking cracks) induced by steel corrosion. The findings of this study provide a fundamental basis for developing an embedded sensor and signal interpretation method for monitoring concrete deterioration due to steel corrosion at various corrosion levels.

• Fashion & Textile Research Journal
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• v.24 no.6
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• pp.667-685
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• 2022

This paper aims to investigate 4D printing materials for soft robots. 4D printing is a targeted evolution of the 3D printed structure in shape, property, and functionality. It is capable of self-assembly, multi-functionality, and self-repair. In addition, it is time-dependent, printer-independent, and predictable. The shape-shifting behaviors considered in 4D printing include folding, bending, twisting, linear or nonlinear expansion/contraction, surface curling, and generating surface topographical features. The shapes can shift from 1D to 1D, 1D to 2D, 2D to 2D, 1D to 3D, 2D to 3D, and 3D to 3D. In the 4D printing auxetic structure, the kinetiX is a cellular-based material design composed of rigid plates and elastic hinges. In pneumatic auxetics based on the kirigami structure, an inverse optimization method for designing and fabricating morphs three-dimensional shapes out of patterns laid out flat. When 4D printing material is molded into a deformable 3D structure, it can be applied to the exoskeleton material of soft robots such as upper and lower limbs, fingers, hands, toes, and feet. Research on 4D printing materials for soft robots is essential in developing smart clothing for healthcare in the textile and fashion industry.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.23 no.1
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• pp.25-30
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• 2023

Leigh syndrome is a rare progressive neurodegenerative mitochondrial disorder with clinical and genetic heterogeneity. Recently, balletic IARS2 variants have been identified in a number of patients presenting broad clinical phenotypes from Leigh and West syndrome to a rare syndrome CAGSSS characterized by cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia syndrome (OMIM#616007). We describe a child with Korean Leigh syndrome with urologic manifestations resulting from a compound heterozygote mutation in IARS2. A 5-year-old girl visited the emergency room with a complaint of abdominal pain accompanied by abdominal distension. Abdominal-pelvic CT showed a markedly distended urinary bladder without definite obstructive lesions. She was diagnosed with neurogenic bladder dysfunction based on a urodynamic study. She had global delayed development due to neurologic regression after 6 months of age and a history of bilateral cataract surgery at the age of 2 years. Her brain magnetic resonance imaging showed symmetrically increased signal intensities in the bilateral putamen and caudate nuclei with diffuse cerebral atrophy. No gene variants were identified through whole-mitochondrial genome analysis. Whole exome sequencing was performed for diagnosis, and compound heterozygous pathogenic variants were identified in IARS2: c.2446C>T (p. Arg816Ter) and c.2450G>A (p. Arg817His). To the best of our knowledge, this is the first case report of bladder dysfunction manifestation in a patient with IARS2-related Leigh syndrome. Thus, it broadens the clinical and genetic spectrum of IARS2-associated diseases.

• Clinical and Experimental Pediatrics
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• v.50 no.1
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• pp.33-39
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• 2007

Purpose : In spite of medical advances, empyema is a serious complication of pneumonia in children. Vaccination practices and antibiotic prescribing practices promote the change of clinical manifestations of empyema and causative organisms. So we made a nationwide clinical observation of 122 cases of empyema in children from 32 hospitals during the 5 year period from September 1999 to August 2004. Methods : Demographic data, and clinical information on the course and management of empyema patients were collected retrospectively from medical records in secondary and tertiary hospitals in Korea. Results : One hundred twenty two patients were enrolled from 35 hospitals. The most frequent age group was 1-3 years, accounting for 48 percent of all cases. The male to female sex ratio was 1.2:1. The main symptoms were cough, fever, respiratory difficulty, lethargy and chest pain in order of frequency. Hematologic findings on admission revealed decreased hemoglobin levels ($10.4{\pm}1.6g/dL$) and increased leukocyte counts ($16,234.3{\pm}10,601.8/{\mu}L$). Pleural fluid obtained from patients showed high leukocyte counts ($30,365.8{\pm}64,073.0/{\mu}L$), high protein levels ($522.3{\pm}1582.3g/dL$), and low glucose levels ($88.1{\pm}523.5mg/dL$). Findings from pleural fluid cultures were positive in 80 cases(65.6 percent). The most common causative agent was Streptococcus pneumoniae. The majority of patients were treated with antibiotics and closed drainage. Some patients needed open drainage (16.4 percent) or decortication (3.3 percent). The mean duration of hospitalization was $28.6{\pm}15.3days$. Conclusion : We analyzed childhood empyema patients during a period of 5 years in Korean children. The most frequent age group was 1-3 years and the most common causative agent was Streptococcus pneumoniaeiae. The majority of patients were treated with antibiotics and close drainage.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1519-1527
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• 2002

Purpose : Although influenza virus is one of the most important causes of acute respiratory tract infections(ARTIs) in children, virus isolation is not popular and there are only a few clinical studies on influenza in Korea. We evaluated the epidemiologic and clinical features of ARTIs by influenza virus in children. Methods : From February 1995 to August 2001, nasopharyngeal aspirations were obtained and cultured for the isolation of influenza virus in children admitted with ARTIs. The medical records of patients with influenza virus infection were reviewed retrospectively. Results : Respiratory viruses were isolated in 997(22.0%) out of 4,533 patients examined, and influenza virus was isolated in 164 cases(3.6%). Influenza virus was isolated year after year mainly from December to April of next year. The ratio of male and female was 1.9 : 1 with a median age of 15 months. The most common clinical diagnosis of influenza virus infection was pneumonia, and fever and cough developed in most patients. There was no difference between influenza A and B infection in clinical diagnoses and symptoms. All patients recovered without receiving antiviral treatment except for one patient diagnosed with pneumonia who had underlying disease of Down syndrome with ventricular septal defect. Conclusion : ARTIs caused by influenza virus developed every winter and spring during the period of study. Because fatal complication can develop in the high risk group, prevention, early diagnosis and proper management of influenza should be emphasized.