• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.1
• /
• pp.17-24
• /
• 2013

In this paper, a micro-mechanical failure prediction program is developed based on SIFT (Strain Invariant Failure Theory) by using the multi-scale modeling method for fiber-reinforced composite materials. And the failure analysis are performed for open-hole composite laminate specimen in order to verify the developed program. First of all, the critical strain invariants are obtained through the tensile tests for three types of specimens. Also, the matrices of strain amplification factors are determined through the finite element analysis for micro-mechanical model, RVE (Representative Volume Element). Finally, the microscopic failure analysis is performed for the open-hole composite laminate specimen model by applying a failure load obtained from tensile test, and the predicted failure indices are evaluated for verification of the developed program.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.9
• /
• pp.3915-3923
• /
• 2012

Prior research has shown empirically that social capital is as a critical factor determining organizational effectiveness. The purpose of this study is to examine the relationship between the social capital, social workers' job satisfaction and organizational commitment in the social welfare organization. For the research, social capital was consisted of trust, norms and network. The results of this study were summarized as follows: Mean analyses showed that social workers perceived the level of social capital had a higher than medium. By using a structural equations modeling(SEM), trust and norms had a positive effect on the social workers' jon satisfaction and organizational commitment. This study finally discusses theoretical implications for future study and practical implications for social capital strategies on the results.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.5
• /
• pp.1082-1088
• /
• 2005

Generating fast round key in AES Rijndael algorithm using three key sizes, such as 128, 192, and 256-bit keys is a critical factor to develop high throughput AES processors. In this paper, we propose on-the-fly round key generator which is applicable to the pipelined and non-pipelined AES processor in which cipher and decipher nodes must be implemented on a chip. The proposed round key generator has modular and area-and-time efficient structure implemented with simple connection of two key expander modules, such as key_exp_m and key_exp_s module. The round key generator for non-pipelined AES processor with support of three key lengths and cipher/decipher modes has about 7.8-ns delay time under 0.25um 2.5V CMOS standard cell library and consists of about 17,700 gates.

• Journal of Intelligence and Information Systems
• /
• v.20 no.4
• /
• pp.59-87
• /
• 2014

In MIS field, the researches on payment services are focused on adoption factors of payment service using behavior theories such as TRA(Theory of Reasoned Action), TAM(Technology Acceptance Model), and TPB (Theory of Planned Behavior). The previous researches presented various adoption factors according to types of payment service, nations, culture and so on even though adoption factors of identical payment service were presented differently by researchers. The payment service industry relatively has strong path dependency to the existing payment methods so that the research results on the identical payment service are different due to payment culture of nation. This paper aims to suggest a successful adoption factor of noble payment service regardless of nation's culture and characteristics of payment and prove it. In previous researches, common adoption factors of payment service are convenience, ease of use, security, convenience, speed etc. But real cases prove the fact that adoption factors that the previous researches present are not always critical to success to penetrate a market. For example, PayByPhone, NFC based parking payment service, successfully has penetrated to early market and grown. In contrast, Google Wallet service failed to be adopted to users despite NFC based payment method which provides convenience, security, ease of use. As shown in upper case, there remains an unexplained aspect. Therefore, the present research question emerged from the question: "What is the more essential and fundamental factor that should takes precedence over factors such as provides convenience, security, ease of use for successful penetration to market". With these cases, this paper analyzes four cases predicted on the following hypothesis and demonstrates it. "To successfully penetrate a market and sustainably grow, new payment service should find non-customer of the existing payment service and provide noble payment method so that they can use payment method". We give plausible explanations for the hypothesis using multiple case studies. Diners club, Danal, PayPal, Square were selected as a typical and successful cases in each category of payment service. The discussion on cases is primarily non-customer analysis that noble payment service targets on to find the most crucial factor in the early market, we does not attempt to consider factors for business growth. We clarified three-tier non-customer of the payment method that new payment service targets on and elaborated how new payment service satisfy them. In case of credit card, this payment service target first tier of non-customer who can't pay for because they don't have any cash temporarily but they have regular income. So credit card provides an opportunity which they can do economic activities by delaying the date of payment. In a result of wireless phone payment's case study, this service targets on second of non-customer who can't use online payment because they concern about security or have to take a complex process and learn how to use online payment method. Therefore, wireless phone payment provides very convenient payment method. Especially, it made group of young pay for a little money without a credit card. Case study result of PayPal, online payment service, shows that it targets on second tier of non-customer who reject to use online payment service because of concern about sensitive information leaks such as passwords and credit card details. Accordingly, PayPal service allows users to pay online without a provision of sensitive information. Final Square case result, Mobile POS -based payment service, also shows that it targets on second tier of non-customer who can't individually transact offline because of cash's shortness. Hence, Square provides dongle which function as POS by putting dongle in earphone terminal. As a result, four cases made non-customer their customer so that they could penetrate early market and had been extended their market share. Consequently, all cases supported the hypothesis and it is highly probable according to 'analytic generation' that case study methodology suggests. We present for judging the quality of research designs the following. Construct validity, internal validity, external validity, reliability are common to all social science methods, these have been summarized in numerous textbooks(Yin, 2014). In case study methodology, these also have served as a framework for assessing a large group of case studies (Gibbert, Ruigrok & Wicki, 2008). Construct validity is to identify correct operational measures for the concepts being studied. To satisfy construct validity, we use multiple sources of evidence such as the academic journals, magazine and articles etc. Internal validity is to seek to establish a causal relationship, whereby certain conditions are believed to lead to other conditions, as distinguished from spurious relationships. To satisfy internal validity, we do explanation building through four cases analysis. External validity is to define the domain to which a study's findings can be generalized. To satisfy this, replication logic in multiple case studies is used. Reliability is to demonstrate that the operations of a study -such as the data collection procedures- can be repeated, with the same results. To satisfy this, we use case study protocol. In Korea, the competition among stakeholders over mobile payment industry is intensifying. Not only main three Telecom Companies but also Smartphone companies and service provider like KakaoTalk announced that they would enter into mobile payment industry. Mobile payment industry is getting competitive. But it doesn't still have momentum effect notwithstanding positive presumptions that will grow very fast. Mobile payment services are categorized into various technology based payment service such as IC mobile card and Application payment service of cloud based, NFC, sound wave, BLE(Bluetooth Low Energy), Biometric recognition technology etc. Especially, mobile payment service is discontinuous innovations that users should change their behavior and noble infrastructure should be installed. These require users to learn how to use it and cause infra-installation cost to shopkeepers. Additionally, payment industry has the strong path dependency. In spite of these obstacles, mobile payment service which should provide dramatically improved value as a products and service of discontinuous innovations is focusing on convenience and security, convenience and so on. We suggest the following to success mobile payment service. First, non-customers of the existing payment service need to be identified. Second, needs of them should be taken. Then, noble payment service provides non-customer who can't pay by the previous payment method to payment method. In conclusion, mobile payment service can create new market and will result in extension of payment market.

• Journal of the Korea Society for Simulation
• /
• v.24 no.2
• /
• pp.1-9
• /
• 2015

The tactical employment is a critical factor to win the war in the modern battlefield. To apply optimized tactics, it needs analyses related to a battle system. Normally, M&S (Modeling & Simulation) has been studied to analyze data in general problems. However, this method is not suitable for military simulations because there are many variables which make complex interaction in the system. For this reason, we suggested the optimized simulation framework based on the M&S by using DPSO (Discrete binary version of PSO) algorithm. This optimized simulation framework makes the best tactical employment to reduce the searching time compared with the normal M&S used by Monte Carlo search method. This paper shows an example to find the best combination of anti-torpedo scenario in a short searching time. From the simulation example, the optimized simulation framework presents the effectiveness.

• Tuberculosis and Respiratory Diseases
• /
• v.85 no.2
• /
• pp.137-146
• /
• 2022

Background: Farinelli breathing (FB) exercise is a typical breathing exercise used by singers. This study aimed to compare effects of FB exercise and diaphragmatic breathing (DB) exercise on respiratory function and symptoms in patients with chronic obstructive pulmonary disease (COPD). Methods: Sixteen patients aged 51-80 years with mild or moderate COPD were recruited for this study. They were divided into two groups: DB group (n=8) and FB group (n=8). Both groups received complete breathing exercise training five times per week for 8 weeks. Their respiratory functions, COPD symptoms, cytokine levels, and oxidative stress variables were analyzed during pre- and post-tests. Dependent variables were compared between pre- and post-tests using paired t-tests. An independent t-test was used to compare variables between the groups. Differences were considered significant at p<0.05. Results: The maximal expiratory pressure (MEP), maximum oxygen consumption (VO₂max), and COPD Assessment Test (CAT) scores changed significantly in the DB group after the 8-week intervention compared to those at pre-test, whereas force vital capacity, forced expiratory volume in the first second, maximum voluntary ventilation, maximal inspiratory pressure (MIP), MEP, VO₂max, CAT score, tumor necrosis factor-α, and malondialdehyde level changed significantly in the FB group at post-test compared to those at pre-test. Moreover, both MIP and MEP in the FB group were significantly higher than those in the DB group. Conclusion: FB exercise improved respiratory functions and COPD symptoms of patients with COPD. It might be an alternative breathing exercise in pulmonary rehabilitation programs for patients with COPD.

• The Journal of Engineering Geology
• /
• v.33 no.4
• /
• pp.717-724
• /
• 2023

Residual shear strength is an important parameter in landslide dynamics and may be considered the critical factor in landslide triggering. Tests were undertaken using Jumunjin sands to examine the effects of smooth and rough surfaces on ring-shear characteristics. Under dense and drained conditions, shear velocities were recorded as 0.01, 0.1, 1, 10, 50, 100 mm s^-1, with shear strength increasing with velocity and producing increasingly fine content. Particle fragmentation may thus increase landslide mobilization when the landslide body is mixed with ambient water in channelized flows.

• The Journal of the Korea Contents Association
• /
• v.19 no.1
• /
• pp.484-495
• /
• 2019

This study attempted to investigate the effects of self-leadership on organizational citizenship behavior and turnover intention among beauty salon employees and analyze the moderating effects of job satisfaction. For this purpose, data were collected for 330 people working in beauty salons and analyzed using SPSS v. 21.0. According to multiple regression analysis, self-leadership revealed a statistically significant positive effect on the OCB and urnover intention Therefore, it was shown that self-leadership is a critical factor. To determine if self-leadership having an influence on the OCB and turnover intention is moderated by job satisfaction, variables were applied to the following models, and hierarchical regression was performed: self-leadershipto model I, job satisfaction to model II, self-leadership and job satisfaction to model III. The results found a statistically significant positive influence in all three models. Therefore, this shows that job satisfaction has a moderating effect on self-leadership, OCB and turnover intention. Self-development education as well as technical training should be strengthened to enhance self-leadership, which leads beauty salon employees' thoughts and behavior in the right direction.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.5
• /
• pp.33-43
• /
• 2021

Kakao M and Kakao page have been merged to form contents corporation, Kakao entertainment. Kakao M has 15 contents management agencies and 4 music labels, in addition to movie and drama productions. Kakao Page currently holds IP rights for about 8,500 content stories. This study explores the relationship between M&A for absorptive capacity and content value chain by considering the factors that determine boundary spanning behaviors. Using the Kakao entertainment in-depth case study as the practical lens, research results of this study are suggested. Kakao's effective M&A activities are critical key factor for absorptive capacity in the entertainment industry and has a strong network with advantage assets. Also, as the contents business becomes even more competitive, Kakao need to venture beyond entertainment boundaries to seize creative opportunities. Kakao entertainment with absorptive capacity and boundary spanning behaviors through M&A and contents value chain best qualified for entertainment dominant strategy.

• 한국균학회소식:학술대회논문집
• /
• 2015.05a
• /
• pp.59-59
• /
• 2015

Cryptococcus neoformans causes life-threatening meningoencephalitis in humans, but the treatment of cryptococcosis remains challenging. To develop novel therapeutic targets and approaches, signaling cascades controlling pathogenicity of C. neoformans have been extensively studied but the underlying biological regulatory circuits remain elusive, particularly due to the presence of an evolutionarily divergent set of transcription factors (TFs) in this basidiomycetous fungus. In this study, we constructed a high-quality of 322 signature-tagged gene deletion strains for 155 putative TF genes, which were previously predicted using the DNA-binding domain TF database (http://www.transcriptionfactor.org/). We tested in vivo and in vitro phenotypic traits under 32 distinct growth conditions using 322 TF gene deletion strains. At least one phenotypic trait was exhibited by 145 out of 155 TF mutants (93%) and approximately 85% of the TFs (132/155) have been functionally characterized for the first time in this study. Through high-coverage phenome analysis, we discovered myriad novel TFs that play critical roles in growth, differentiation, virulence-factor (melanin, capsule, and urease) formation, stress responses, antifungal drug resistance, and virulence. Large-scale virulence and infectivity assays in insect (Galleria mellonella) and mouse host models identified 34 novel TFs that are critical for pathogenicity. The genotypic and phenotypic data for each TF are available in the C. neoformans TF phenome database (http://tf.cryptococcus.org). In conclusion, our phenome-based functional analysis of the C. neoformans TF mutant library provides key insights into transcriptional networks of basidiomycetous fungi and ubiquitous human fungal pathogens.