• Journal of Information Technology Applications and Management
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• v.12 no.4
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• pp.13-24
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• 2005

The sensor network is a key component of the ubiquitous computing system which is expected to be widely utilized in logistics control, environment/disaster control, medical/health-care services, digital home and other applications. Nodes in the sensor network are small-sized and exposed to adverse environments. They are demanded to perform their missions with very limited power supply only. Also the sensor network is composed of much more nodes than the wireless ad hoc networks are. In case that some nodes consume up their power capacity, the network topology should change, and rerouting/retransmission is necessitated. Communication protocols studied for conventional wireless networks or ad hoc networks are not suited for the sensor network resultantly. Schemes should be devised to control the efficient usage of node power in the sensor network. This paper proposes a medium access protocol to enhance the efficiency of energy consumption in the sensor network node. Its performance is analyzed by simulation.

• Journal of electromagnetic engineering and science
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• v.12 no.1
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• pp.1-7
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• 2012

In this paper, we investigated the throughput of a cognitive radio network where two primary frequency channels (PCs) are sensed and opportunistically accessed by N secondary users. The sharing sensing member (SSM) protocol is introduced to sense both PCs simultaneously. According to the SSM protocol, N SUs (Secondary User) are divided into two groups, which allows for the simultaneous sensing of two PCs. With a frame structure, after determining whether the PCs are idle or active during a sensing slot, the SUs may use the remaining time to transmit their own data. The throughput of the network is formulated as a convex optimization problem. We then evaluated an iterative algorithm to allocate the optimal sensing time, fusion rule and the number of members in each group. The computer simulation and numerical results show that the proposed optimal allocation improves the throughput of the SU under a misdetection constraint to protect the PCs. If not, its initial date of receipt shall be nullified.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11S
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• pp.3289-3298
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• 1999

E-mail system is the most important service that enterprises and normal users in internet use. However, because a data security is not satisfied yet, and E-mail system with security service is essential. In this paper, We implemented the E-mail system with Certification of Delivery that was not provided in prior mail system with basic security services and can prove that sender's document is properly sent to the intended receipt. And an implementation of the system used Java Cryptography API.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.450-452
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• 2001

In this paper, we proposed the automatic postal drop-off system based on the microprocessor board or PC. The weight of the small postal package is transmitted from the electronic scale and user-entered addresses and delivery rate are processed by the controller to calculate the fee. For 24 hour out-door operation and maintenance, non-cash payment methods such as credit card payment is used. The post stamp and receipt are printed by the thermal printer. For the electronic processing of the parcel, serial code is also printed on the stamp and receipts in bar code format. The parcel information obtained by the automatic postal drop-off system is transferred to remote central system by dial-up modem shared by the on site office. The proposed system and its control software are built for prototype model operation and the result met the design requirements. For real time processing, data reception through three serial ports is handled by interrupt routine. The proposed system is expected to be applied for commercial logistics system and pc automation system.

• Journal of Labour Economics
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• v.25 no.1
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• pp.75-95
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• 2002

Using 3 years of panel data on nearly 3,507 households, the Korea Labor Income Panel Survey(KLIPS) data, the authors measure the determinants of poverty and unemployment, and the extents to which poverty influenced unemployment. The probit analysis of unemployment shows that unemployment probability is lower, when male, lower age and is higher, high-school and over junior college, work duration is over 3 years. The probit analysis of poverty shows that poverty probability is lower, when male, higher education level, longer career. specially unemployment and social insurance is determinants of increasing poverty. Bivariate probit model of unemployment and poverty also provides similar findings to those probit analysis and shows an evidence of the influence of unemployment on poverty along with the positive role of social welfare policy such that social welfare receipt reduces the impact of unemployment on poverty.

• International Journal of Human Ecology
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• v.16 no.2
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• pp.21-31
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• 2015

This study explored determinants of family support that young renter households received to afford their housing costs. Microdata set of the 2014 Korea Housing Survey was used as secondary data for the study. Total 1,752,899 households headed by persons between 20 and 34 years of age and whose rental type was either Jeon-se or monthly rental with deposit in private rental units were selected as study subjects. For the data analysis, a series of discriminant analysis was conducted using IBM SPSS 21.0. Major findings were as follows. (1) Among the subjects, 28.2% were found to receive financial support from parents or other relatives. (2) To see the discriminant analysis results, a linear combination of seven household and housing characteristics (householder's gender, whether or not the householder worked in the previous week, whether or not the householders have a spouse, tenure type, structure type, location and deposit amount) could explain 44.6% of variance in young renter households' receipt of family support with a prediction accuracy of 77.2%. (3) To summarize the final discriminant model, Jeon-se renter households in location other than Incheon or Gyeonggi Province living in a unit in structure other than multifamily structure headed by younger householders that did not worked previous week or without spouse; with a greater deposit had the maximum tendency to receive family support to pay rental costs.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.12
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• pp.1403-1410
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• 2015

The purpose of this study is to provide ways to utilize and create valuable medical information utilizing Medical Big Data created by field in hospital information system. The results of this study first creates new medical information of Medical Information system through medical big data analysis and integration of created data of PACS linked with many kinds of testing equipment and medical image equipment along with medical treatment information. Medical information created in this way produces various health information for treatment and prevention of disease and infectious disease. Second, it creates profit statistics information in various ways by analyzing medical big data accumulated through integration of billings and receipt, admission breakdown of patients. Profit statistics information created in this way produces various administration information to be utilized in profit anaysis and operation of medical institution. Likewise, data integration of personal health history, medical information of public institutions, medical information created in hospital information system produces valuable medical health information utilizing medical data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.731-734
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• 2011

This paper proposed the Low power configuration of Single hop WSN(Wireless Sensor Network) system. When the RF communication is done each tag node during the WSN systems operating, power consumption is greatest. There for, if you configure the Network with the RF communication module turn on/off periodically, power consumption less then operating the module all the time without it toggles. However, some data omissions may occur in which transmission and receipt is done. So this paper proposed the algorithm for low power system without data omissions.

• Journal of Distribution Science
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• v.18 no.5
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• pp.99-109
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• 2020

Purpose: This study aims to develop and empirically analyze a research model in order to comprehend the relationship among the service quality of market-wholesaler system, re-transaction intention, and recommendation intention of forwarder. Further, we suggest new six factors reflecting the service quality of market-wholesaler system and highlight market expansion of forwarder as a mechanism in the relationship. Research design, data and methodology: The authors developed the new scales measuring the service quality of market-wholesaler system (i.e. trade price, price fluctuation, payment receipt, settlement period, trade information, and customer service) and conducted a cross-sectional survey for 439 forwarders in a wholesale market. And then we performed a series of path analyses to test hypotheses. The hypotheses are as follows. [H1] The service quality of market-wholesaler system will positively affect forwarders' market expansion, [H2] Forwarders' market expansion will positively affect their re-transaction intention, [H3] Forwarders' market expansion will positively affect their recommendation intention, [H4] Forwarders' re-transaction intention will positively affect their recommendation intention. Results: The results showed that all the six factors for the service quality of market-wholesaler system were positively related to market expansion of forwarders. There was a differential effectiveness in the six factors of the service quality. More specifically, the positive effect of customer service factor was the strongest on market expansion of forwarders. And the respective effects of trade price, price fluctuation, settlement period, trade information factors were followed in order. The positive effect of payment receipt factor was the weakest on market expansion of forwarders. Also, market expansion of forwarders was positively related to their re-transaction intention and recommendation intention. Furthermore, market expansion of forwarders was indirectly related to recommendation intention through re-transaction intention as well. Conclusions: The research findings provide important theoretical and practical implications. This study is the first to attempt to test the perception of forwarders for the service quality of market-wholesaler system by developing and using the new scales. Also, there has been a sharp controversy about the effectiveness of market-wholesaler system. The findings support that market-wholesaler system would be activated by empirically verifying the effectiveness of the service quality on the various outcomes.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.693-702
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• 2020

The present study aims to investigate the impact of tourism growth on human development in Indian economy. For this purpose, the study uses annual data from 1980 to 2018 and utilizes two proxies for tourism growth - tourism receipt and tourist arrivals - and uses human development index calculated by UNDP. The study uses control variables such as government expenditure and trade openness. The study employs auto regressive distributed lag (ARDL) approach to investigate the cointegrating relationship among the variables in the model. Further, the study also explores the causal nexus between tourism sector and human development by using the Toda-Yamamoto Granger non-causality test. The result of ARDL bounds test reveals the existence of cointegrating relationship between human development indicators, government expenditure, trade openness, and tourism sector growth. The cointegating coefficient confirms a positive and significant relationship between tourism sector growth and human development in India. The causality result suggests that economic growth and tourism have a positive impact while trade openness has a negative impact on human development in India. The major findings of this study suggest that tourism plays an important role in the socio-economic development of Indian economy in recent years and the country must develop this sector to achieve sustainable development.