• Proceedings of the IEEK Conference
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• 대한전자공학회 2004년도 ICEIC The International Conference on Electronics Informations and Communications
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• pp.189-192
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• 2004

This paper focuses on a TCP window-based flow control mechanism with Explicit Congestion Notification (ECN). We investigate the fundamental problem of achieving a fair window control for TCP, which cooperates with ECN. This is done by using feedback congestion pricing as a means of estimating the state of bottleneck router. The problem is solved by achieving network optimal performance, which maximize the total user utilities. We then look at the simulation of such scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권6호
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• pp.1101-1112
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• 2011

The Multiuser Eigenmode Transmission (MET) has generated significant interests in literature due to its optimal performance in linear precoding systems. The MET can simultaneously transmit several spatial multiplexing eigenmodes to multiple users which significantly enhance the system performance. The maximum number of users that can be served simultaneously is limited due to the constraints on the number antennas, and thus an appropriate user selection is critical to the MET system. Various algorithms have been developed in previous works such as the enumerative search algorithm. However, the high complexities of these algorithms impede their applications in practice. In this paper, motivated by the necessity of an efficient and effective user selection algorithm, a low complexity recursive user selection algorithm is proposed for the MET system. In addition, the fairness of the MET system is improved by using the combination of the proposed user selection algorithm and the adaptive Proportional Fair Scheduling (PFS) algorithm. Extensive simulations are implemented to verify the efficiency and effectiveness of the proposed algorithm.

• Journal of Medicine and Life Science
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• 제19권1호
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• pp.14-19
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• 2022

We investigated the safety and efficacy of pemetrexed monotherapy in patients with lung adenocarcinoma and various renal conditions, including chronic kidney disease. We also analyzed whether baseline renal function affected progression-free survival (PFS). We retrospectively analyzed 71 patients who received maintenance-and second-line pemetrexed monotherapy. Patients were divided into two groups according to estimated glomerular filtration rate (eGFR): fair eGFR (>60 mL/min/1.73 m²) and lower eGFR (59 mL/min/1.73 m² or less). The safety and efficacy were evaluated for each group. Median ages were 73.2 years in the lower eGFR group (n=28) and 64.5 years in the fair eGFR group (n=43). Patients with a lower eGFR achieved a median PFS of 4.7 months, while the median PFS for patients with a fair eGFR was 2.7 months. The difference between the two groups was not statistically significant (P=0.075). Both groups showed treatment-related low-grade hematological and non-hematological adverse events. Pemetrexed monotherapy is safe and effective in patients with lung adenocarcinoma with a lower eGFR.

• Korean Journal of Health Education and Promotion
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• 제32권2호
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• pp.75-84
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• 2015

Objectives: This study examines that the compatibilities between the health promotion programs in community health center and the leading health indicators in National Health Plan. Methods: We analyzed health promotion programs associated with three health indicators; smoking(smoking rate in male), alcohol use(alcohol use rate in adults), obesity(obesity rate) in twenty five community health centers in Seoul. First, we classified three groups(excellent, fair and poor groups) using average scores of Seoul, that of Korea and National Health Plan2010 goals in three health indicators. Afterwards, we examined the compatibility between contents of health promotion programs regarding leading health indicators and the specific program activities. Results: The compatibility levels between health indicators and contents of health promotion programs was 80 % for smoking among fair and poor groups while fair and poor for smoking reported 60% and 70%, respectively. For obesity, excellent group reported 80% and fair group had 91%. Conclusion: In conclusion, although all districts were able to access available data for health indicators and health statistics every year, it seems that they did not only utilize these data enough in conjunction with health promotion programs but also did not integrate specific activities according to National Health Plan systematically.

• Journal of Institute of Control, Robotics and Systems
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• 제6권8호
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• pp.638-651
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• 2000

When the bandwidth resources in a packet-switched network are shared among sessions by MAX-MIN flow control each session is required to transmit its data into the network subject to the MAX-MIN fair rate which is solely determined by network loadings. This passive behavior of sessions if fact can cause seri-ous QoS(Quality of Service) degradation particularly for real-time multimedia sessions such as video since the rate allocated by the network can mismatch with what is demanded by each session for its QoS. In order to alleviate this problem we extend the concept of MAX-MIN fair bandwidth allocations as follows: Individual bandwidth demands are guaranteed if the network can accommodate them and only the residual network band-width is shared in the MAX-MIN fair sense. On the other hand if sum of the individual bandwidth demands exceeds the network capacity the shortage of the bandwidth is shared by all the sessions by reducing each bandwidth guarantee by the MAX-MIN fair division of the shortage. we present a novel flow control algorithm to achieve this extended MAX-MIN fairness and show that this algorithm can be implemented by the existing ATM ABR service protocol with minor changes. We not only analyze the steady state asymptotic stability and convergence rate of the algorithm by appealing to control theories but also verify its practical performance through simulations in a variety of network scenarios.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제39C권12호
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• pp.1280-1288
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• 2014

In this paper, we use the ECMA-392 standard, the first cognitive radio networks to meet the demand for IT services in the ship. First, we learn about ECMA-392-based network and examine the consideration and the problems for assigning channels to the device. And, we propose a fair channel resource allocation to ensure efficiently channel required by device groups in ECMA-392 MAC protocol. This is a method to reallocate the channels fairly with considering the channel assignment parameters to a new device group and existing device groups. The simulation results show that the proposed scheme improves throughputs compared to the existing one.

• Physical Therapy Rehabilitation Science
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• 제11권3호
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• pp.311-320
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• 2022

Objective: To investigate the reliability and validity of static balance measurements using an acceleration sensor and a gyroscope sensor in smart phone inertial sensors. Design: Equivalent control group pretest-posttest. Methods: Subjects were forty five healthy adults aged twenty to fifty-years-old who had no disease that could affect the experiment. After pre-test, all participants wore a waist band with smart phone, and conducted six static balance measurements on the force plate twice for 35 seconds each. To investigate the test-retest reliability of both smart phone inertial sensors, we compared the intra-correlation coefficient (ICC 3, 1) between primary and secondary measurements with the calculated root mean scale-total data. To determine the validity of the two sensors, it was measured simultaneously with force plate, and the comparision was done by Pearson's correlation. Results: The test-retest reliability showed excellent correlation for acceleration sensor, and it also showed excellent to good correlation for gyroscope sensor(p<0.05). The concurrent validity of smartphone inertial sensors showed a mostly poor to fair correlation for tandem-stance and one-leg-stance (p<0.05) and unacceptable correlation for the other postures (p>0.05). The gyroscope sensor showed a fair correlation for most of the RMS-Total data, and the other data also showed poor to fair correlation (p<0.05). Conclusions: The result indicates that both acceleration sensor and gyroscope sensor has good reliability, and that compared to force plate, acceleration sensor has unacceptable or poor correlation, and gyroscope sensor has mostly fair correlation.

• Journal of Distribution Science
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• 제10권11호
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• pp.55-60
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• 2012

Purpose - This study aims to suggest policy directions for small retail markets in Korea by statistical analysis, which would help small retailers who are facing various difficulties. Research design, data, methodology - This study diagnoses the problems faced by small retail industries in Korea based on government statistics. In addition, this study identifies three areas for successful collaboration between the SSMs and traditional markets-information distribution, products, and fair trade. Results - This study makes three recommendations-information distribution, products, and fair trade. This includes activation of the existing mutual collaboration efforts, channels, CSR report writing and publicity, ethical management cooperation seminars, contract systems of no return, establishment of staff outsourcing standards, and support for suppliers' organizations. Conclusions - Our suggestions for a collaborative system (based on the three suggestions) show that collaboration rather than confrontation between large and small markets can lead to a sales increase of 2,258.2 billion Won, which is equivalent to the sales loss in 11 traditional markets in one year in Busan.

• The Korean Journal of Financial Management
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• 제26권3호
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• pp.103-138
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• 2009

In this article we examine a unique data set of intraday fair disclosure(FD) releases to shed light on market efficiency within the trading day. Specifically, this paper analyze the response of stock prices on fair disclosure disseminated in real-time through KIND(Korea Investor's Network for Disclosure) on Korea stock exchange during the period from January 2003 to September 2004. We find that the prices of stock experiences a statistically and economically significant increase beginning seconds after the fair disclosure is initially announced and lasting approximately two minutes. The stock price responds more strongly to fair disclosure on smaller firm but the response to fair disclosure on the largest firm stock is more gradual, lasting five minutes. We also examine the profitability of a short-term trading strategy based on dissemination of fair disclosure. After controlling for trading costs we find that trader who execute a trade following initial disclosure generate negative profits, but trader buying stock before initial disclosure realize statistically significant positive profit after two minute of disclosure. Summarizing overall results, our evidence supports that security prices on Korea stock exchange reflects all available information within two minutes and the Korea stock market is semi-strongly efficient enough that a trader cannot generate profits based on widely disseminated news unless he acts almost immediately.

• Journal of Korean Library and Information Science Society
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• 제33권4호
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• pp.19-35
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• 2002

European Union has recently encouraged its member states to enforce the Public Lending right that is a remuneration system for free lending service in public libraries. This study reviews the problem and the actual conditions of Public Lending Right System which is systematized in European Union and a few advanced countries. By analyzing the present state of many states which is running the public lending right system, this study also explores a reasonable compensation system which remunerate a copyrighter for his rending right md ensure the fair use tradition in libraries.