• Journal of Communications and Networks
• /
• v.9 no.3
• /
• pp.236-246
• /
• 2007

This paper investigates the performance of the transmission control protocol (TCP) transport protocol over IEEE 802.11 infrastructure based wireless networks. A wireless link is generally characterized by high transmission errors, random interference and a varying latency. The erratic packet losses usually lead to a curbing of the flow of segments on the TCP connection and thus limit TCP's performance. This paper examines the impact of the lossy nature of IEEE 802.11 wireless networks on the TCP performance and proposes a scheme to improve the performance of TCP over wireless links. A negative acknowledgment scheme, selective negative acknowledgment (SNACK), is applied on TCP over wireless networks and a series of ns-2 simulations are performed to compare its performance against that of other TCP schemes. The simulation results confirm that SNACK and its proposed enhancement SNACK-S, which incorporates a bandwidth estimation model at the sender, outperform conventional TCP implementations in 802.11 wireless networks.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.11B
• /
• pp.989-997
• /
• 2008

The reverse acknowledgment (RA) scheme supports a fast loss recovery for negative acknowledgment (NAK)-based selective repeat automatic repeat request (SR-ARQ) by detecting a retransmission failure quickly before a retransmission timer expires. In this paper, we evaluate the performance of a NAK-based SR-ARQ protocol with the RA scheme and compare it with the conventional NAK-based SR-ARQ protocol. Particularly, we propose a simple analysis model for the transport delay of the NAK-based SR-ARQ protocol considering the traffic condition, the retransmission persistence, the timer-based retransmissions and the RA scheme's behavior. Both NAK-based SR-ARQ protocols with and without the RA scheme are implemented by using the OPNET simulator. We verified the analysis model's accuracy through the simulation results. Also, we evaluate the performance of the NAK-based SR-ARQ protocol with the RA scheme based on analysis and simulation results.

• Korea Journal of Hospital Management
• /
• v.16 no.4
• /
• pp.67-84
• /
• 2011

The open Hospital Attending Physician System has been discussed and operated for developing the efficiency and the substitutes for an increase in medical expenses, for overlapping investment in medical resources, and for normalization of medical delivery system. This study assessed the related factors to the acceptance and introduction of Attending Physicians on ophthalmologist. Data was collected mail response to 179 ophthalmologists in 2005. Applying multilevel logistic regression, we examined the relationship between their acknowledgment, attitude and acceptance of the open Hospital Attending Physicians System. The percentage of participation in Hospital Attending was indicated to be 3.9%. The 44.7% of all participants agreed to adopting the Hospital Attending, 33.5% of doctors are willing to participate in the future. The positive and normal attitude of physician toward the Hospital Attending is 6.6 times (95%CI 1.315, 33.138) and 55.2 times(95%CI 11.352, 268.347) more than that of negative after adjustment for other variables. Attitude was found to be the important factor influencing physicians' participation in the Attending Hospital. Thus, it is need to development and implication for the strategies that lead the practical necessity and positive attitude toward the Attending Hospital.

• The Journal of Industrial Distribution & Business
• /
• v.12 no.12
• /
• pp.25-33
• /
• 2021

Purpose: This paper estimates the impact of the epidemic crisis on election outcomes through investigating the effect of Covid19 crisis on election results of 21st General Election held in April 15th 2020 in Korea. Research design, data and methodology: This study employs Ordinary Least Square (OLS) method using district-level data from Seoul and Gyeonggi province available at National election data in Korea. Results: Despite the current crisis in Korea, Covid-19 has had positive effects on voter turnout on average, after controlling for other factors. On the other hand, the effect of Covid-19 on the voter turnout was negative in districts with a larger aging population and higher health insurance premiums. In addition, Covid-19 negatively impacted vote shares for the incumbent party, while its rival party saw gains in their votes. Conclusion: The effect of Covid-19 election outcomes in Korea is distinct from other countries due to the nationwide acknowledgment of the Korean government's achievement in managing the epidemic. This implies that the crisis management ability of a government is crucial in gaining support for an incumbent party in future elections. Countries facing upcoming elections need to implement acceptable Covid-19 restriction policies as well as economic support for compensation to reap similar benefits.

• East Asian Journal of Business Economics (EAJBE)
• /
• v.9 no.4
• /
• pp.81-92
• /
• 2021

Purpose - Work stress environment is expanding alongside the speed of worldwide change and psychological well-being concerns are coming about because pressure over-burden can bring about lost workdays, lower representative usefulness, and high occupation turnover rates. For this reason, this study investigates to provide how practitioners can manage employee work stress using health psychology based on prior studies. Research design, Data, and methodology - Qualitative textual research involves collecting and analyzing various non-numeric data to establish different concepts or opinions in prior literature. That means that the present researcher carried out qualitative research in multiple ways, investigating many kinds of previous textual data, such as prior published peer-reviewed resources and case studies analysis. Result - The results revealed that directed symbolism has been displayed to improve prosperity and tranquility among employees with an assortment of persistent infections. Like diaphragmatic breathing, reflection practices consolidate zeroing in on a particular article or sensation (like breathing) while at the same time separating from other distracters and controlling inward encounters (for example, feelings, musings) through non-critical acknowledgment. Conclusion - This research proposes that intellectual rebuilding or figuring out how to perceive maladaptive musings and change them to reflect more versatile; judicious idea examples can fundamentally further develop temperament, diminish pressure, and reduction negative feelings for employees.

• The Journal of the Korea Contents Association
• /
• v.17 no.7
• /
• pp.222-235
• /
• 2017

The purpose of this study is to analyze the perception of Korean universities' education specialists and seek direction for the development of MOOCs. To investigate this, 64 Korean university education specialists were surveyed about the educational goals of MOOCs and their perception of micro and macro issues. As a result, Korean university education specialists recognized MOOCs' educational goals as an innovation of education methods. Also, negative acknowledgment that issuance of certificates would cause confusion in the degree system, which is interpreted as a tendency to recognize MOOCs as a complementary material. On a macroscopic level, overall outlook was negative for K-MOOC. However, since K-MOOC is highly perceived to be subversive, it is necessary to discuss the possibility of using MOOCs. Accordingly, it suggested the institutional improvement for the utilization of K-MOOC and the possibility of joint development between universities.

• Journal of Korean Academy of Nursing
• /
• v.28 no.2
• /
• pp.369-379
• /
• 1998

Despite acknowledgment that pain is likely to be a major problem for many older adults, it is difficult to estimate the frequency of pain problems for this population. The main purpose of this study was to identify the various characteristics of chronic pain in the elderly by gender. It examines by gender, pain frequency, pain intensity, number of chronic pain sites, localization of pain, impact on activities, methods of pain management, and effects of chronic pain management. The subjects were 189 elderly people(65 years and older) living in an urban area. They were surveyed at their homes. They were surveyed by interview using a closed-ended questionnaire. The survey was done from Nov. 6th. to Dec. 6th. 1997. Descriptive statistics were used to determine all of the reported pain variables. Chi-square tests were used to determine crude differences between pain intensity and gender. T-test was used to determine differences in number of pain sites between men and women. The findings are as follows ; Of the 189 subjects, 83.6% reported experiencing pain, and men reported a lower prevalence (69.5%) than women(89.2%). Women had significantly more severe pain than did men(p=.001). Lower back pain(20.2%) and leg pain(20.2%) were the most prevalent, followed by knee pain(17.4%), arm pain(13.3%), neck and shoulder pain(11.6%), and headache(9.9%). Women experienced more multiple localizations of pain(p=.0001), the greatest impact was on movement (83.5%) , followed by usual activities(60.8%), sleep(49.4%), visiting(29.1%), and hobbies and recreations(50.0%). No differences were observed between men and women in the proportion of subjects reporting a negative impact on each of these activities. The methods of pain management were hospital visit(70.9%), drug store medication(46.7%), oriental medicine clinic(32.9%), endurance(13.3%), self-management(6.3%). Drug therapy was the most effective pain management strategy(94%), followed by physical therapy(63%) and accupuncture.byssocausis(55%). The conclusion : Pain is a symptom of great clinical importance that is often associated with disability, loss of independence, and reduced quality of life. In this study chronic pain symptoms were common but unevenly distributed in men and women. The results further advance understanding of the experience and impact of pain by gender. Future studies should incorporate questions that gather systemic and more detailed information on the characteristics of pain, especially by gender and by age.

• Korean Journal of Childcare and Education
• /
• v.11 no.4
• /
• pp.211-237
• /
• 2015

The purpose of this study was to explore early childhood pre-service teachers' belief in homosexuality. This study applied the Q-method to investigate teachers'subjective awareness of homosexuality. Using an open questionnaire, we asked participants to describe how they think about homosexuality. Forty-five pre-service teachers were Q-sampled. Using the QUANL program, 45 statements were classified into 9 levels. Results revealed that image types of early childhood pre-service teachers can be classified into four distinguished categories: 1) type of respect: to regard gays and lesbians as normal people who love the same sex, 2) type of acknowledgment: to regard them as very unique people who attract people's attention, 3) type of relation-denying: to regard them as someone who were born totally differently, and 4) type of extremely denying-to regard them not being respected and disgusting. Most of the teachers seemed to have a tendency to acknowledge and respect individuals'sexual orientation. However, some pre-service teachers still have a negative attitude toward homosexuality. The significance of this study is to reveal the silenced issue, that is, sexual orientation in the field of early childhood multicultural education. Teachers can have a strong effect on young children's belief about sexual identity and sexual orientation. It would be important to look back on educators'perspective on homosexuality before suggesting the direction of multicultural education of young children related to the issue of sexual orientation.