• Communications for Statistical Applications and Methods
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• v.14 no.2
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• pp.301-307
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• 2007

A effective teaching method on correlation coefficient for elementary level statistics course is discussed in this article. The well known inequalities, such as Theorem 368 of Hardy et al. (1952), are used for the interpretation of concept of covariance. An Excel example is provided for the illustration of concept of correlation coefficient.

• Communications for Statistical Applications and Methods
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• v.4 no.1
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• pp.185-191
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• 1997

Bayesian estimation of multinomial and Poisson parameters under starshped restriction is considered. Most Bayesian estimations in order restricted statistical inference require the high-dimensional integration which is very difficult to evaluate. Monte Carlo integration and Gibbs sampling are among alternative methods. The Bayesian estimation considered in this paper requires only evaluation of incomplete beta functions which are extensively tabulated.

• Journal of electromagnetic engineering and science
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• v.10 no.1
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• pp.6-12
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• 2010

In this paper, highly efficient class-F power amplifiers(PAs) with harmonic-controlling transmission lines(TLs) were built for cellular and WLAN applications at 840 MHz and 2.4 GHz each. Also, based on these single-band PAs, a dualband class-F PA was designed after a careful investigation into the harmonics of the two frequencies. The harmonic-controlling TL was designed for the class-F operation at dualband by switching the length of the shunt $\lambda$/4 TL part, while the series $\lambda$/4 TL is optimized for both frequencies. To verify the performance, two class-F PAs optimized at each frequency and a dualband class-F PA at the corresponding frequencies were built with the secondand the third-harmonic control circuits at each frequencies. As a result, the PA#1 at 840 MHz has a peak drain efficiency of 81.2 % with an output power of 24.4 dBm, while the PA#2 at 2.35 GHz shows a drain efficiency of 94.5 % with an output of 22.8 dBm. Finally, the dualband class-F PA#3 showed 60.5 % and 50.9 % drain efficiencies at 840 MHz and 2.4 GHz, with powers of 23.8 dBm and 19.62 dBm, respectively.

• Journal of The Korean Association of Information Education
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• v.6 no.1
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• pp.64-74
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• 2002

The purpose of this paper is to review the importance of situated cognition and the features of MOO(Multi-user Object Oriented)environments for effective foreign language learning. Learning foreign languages is beyond simply recalling for the vocabularies or expression usages of targeted languages. As much the same as children naturally acquire their mother languages among active and social interactions with other surrounding people, foreign languages should be told in the circumstances and contexts for authentic applications of foreign languages. The MOO, one of the virtual realities with spatial metaphors on the text basis, has been gaining high attentions from educational fields, thanks to the strong functions of social contexts and learner interactions. This paper approaches the features of MOO as foreign language learning environments, in terms of activity, context and interaction.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.17-25
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• 2011

The wireless mesh networks are recently getting much attention for commercial applications. In such networks, the service should be uninterrupted when roaming from one domain to another while the authentication for a secure access should be maintained. The challenge is to consider the authentic coordination between the home domain and foreign domains and the maintenance of local authenticity between foreign domains. In this paper, a novel authentication method is presented so that a mobile mesh node can be effectively authenticated and obtain an secure connection in foreign domains. In the proposed method, the authentication process does not rely on an end-to-end connection between the foreign domain and the home domain. Even without a connectivity to the home domain, the foreign domain can provide an effective authentication of a mesh node by consulting one of the neighboring foreign domains that has been visited by the mobile mesh node. In order to verify the performance of our proposed method, a qualitative analysis has been performed and compared to those of conventional methods. The results show that our method is superior to the conventional ones in terms of authentication response time and authentication service robustness.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.78-78
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• 2016

For the past three decades, extensive research has been performed in the surface design of new polymers for a variety of medical applications. Great progress in therapeutics and diagnostics can be attributed to these scientific advances in biomedical polymers. A variety of bioinert materials or bioactive materials using drugs, cells, and growth factors are widely utilized for the implants, devices and tissue regeneration. These materials provide an improved biocompatible materials to host, to significantly decrease or increase the host/tissue/blood response to the foreign materials. In the future, biomaterials will play a different role in modern therapeutics. New materials will be tailored to interact more on a protein and cellular level to achieve high degree of biocompatibility, biospecificity and bioacitivity. In this presentation, various biocompatible materials based on surface/bulk engineering will be demonstrated, which can be utilized as therapeutics implants and therapeutic vehicles for biologically active molecules such as cell, protein /peptide and gene.

• International journal of advanced smart convergence
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• v.8 no.2
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• pp.18-29
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• 2019

In the field of Human-Computer Interaction design, persuasive design has gradually been applied to the system development and design process, especially for mobile application design. However, most mobile applications have hitherto a very short using lifecycle. Especially, design features with long-term persuasive effectiveness remain to be further researched and developed. In this study, we focused on investigating and identifying the durative persuasive design characteristics through a data mining process and evaluating the durative effectiveness through a long-term observation process. Total five hundred healthcare-related mobile applications were selected from Apple iTunes Store and a mixed method was conducted to extract the most common persuasive design characteristics. Based on the results of extraction, a representative healthcare-related mobile application was selected as experimental subject. Total one hundred and twenty participants were observed during a six-months experiment and the monitoring data of app usage of all participants was collected once a week. According to the evaluation model for behavior change identification process, participants with habit formation features were proved to have a significant long-term perception level for ten persuasive design characteristics. Further interview research was performed to investigate the participant's long-term perceptions on those characteristics for the purpose of identifying the durative persuasions. The results indicated that a long-term durative effectiveness can be observed and healthcare-related apps designed with those characteristics could have durative effectiveness. This study may contribute to the improvement of future mobile application designs in user experience and durative persuasion, as well as bringing future benefits for both mobile application developers and users.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.223-229
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• 2014

The acoustic cleaning system is widely used to remove foreign materials in factories, such as thermal power plants and incinerators. However, the acoustic cleaning systems tend to be clogged by foreign materials. In this paper, we develop a wireless sensor network for the sound wave detection in order to monitor proper operations in the acoustic cleaning systems. We observe that the developed wireless sensor network for the wave detection shows a stable operation in various industrial environments of wide temperature ranges. We also develop a data gathering device, which displays the current status of the sound generator and several values detected from the wireless sensor.

• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.3
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• pp.121-136
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• 2019

The fashion market is expanding and competition is intensifying due to the contraction of consumption in response to the economic recession and changes in trends. In this study, design characteristics reflecting the brand identity and trend are analyzed as important factors for success. In this study, we will look at the design characteristics of knitwear among SPA brand products and help to plan knit designs. First, six brands were selected based on the sales and the number of stores in domestic and foreign SPA brands. The selected brands include UNIQLO, ZARA, H&M, SPAO, TOPTEN, and 8Seconds. We have selected weft knitting knitwear products(1,736 pieces), which are currently sold in domestic and foreign SPA brands, as silhouette items, knitwear design items, gauges, colors, patterns, images, and items as analysis items to analyze the causes of the differences in the design characteristics of domestic and foreign knitwear. The SPA brand has a wide range of tattoo floors, emphasizing practical aspects, a silhouette that fits the body, and a comfortable daily style. Domestic and foreign SPA brands did not show much difference, but Korean brands had a lower diversity of organization and used color for stable sales, showing a lower concern in trend and strong point color applications. If foreign brands pursue femininity based on a sexy image, Korean brands displayed a difference, emphasizing cute images. As for other design factors, it was found that brand identity was reflected more than domestically. As the cycle of trends becomes shorter, fast fashion is expected to continue in the future, and it is hoped that this research will be used as useful data for design projects of domestic companies.

• Journal of Environmental Health Sciences
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• v.47 no.3
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• pp.205-226
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• 2021

Objectives: Biomonitoring programs have been widely implemented in the field of environmental health, both in Korea and worldwide. Recently, it has been suggested that the storage, management, and utilization of biosamples collected from biomonitoring programs should be organized based on a biobank system. Therefore, we attempted to review the current status of representative biomonitoring programs and biobank systems that have been implemented in Korea and in other countries. Methods: We searched for bio-samples collected in domestic and foreign biomonitoring programs and their applications. For this, we referred to research papers, homepages hosted by biomonitoring programs, and project reports. We also checked information for biobanks related with biomonitoring programs, including the operating systems, facilities, technologies, and regulations of biobanks. Results: We summarized six domestic and 32 foreign biomonitoring programs. These biomonitoring programs collected bio-samples to determine the relationship between environmental chemicals and diseases. Domestically, bio-samples from KoNEHS, KorSEP, MOCEH, KoCHENS, and KorEHS-C were stored at -80℃ in a deep freezer at the National Institute of Environmental Research, while KNHANES samples were stored at Korea Biobank, which has a stabilized biobanking system with a well-established database. Nine foreign biomonitoring programs (JECS, China-NHBP, CKB, CHMS, NHANES, GerES, Germaan ESB, MoBa, and UK Biobank) were ongoing for large populations. Among them, CKB, GermanESB, and UK biobank have been maintained for at least 10 years with their own biomonitoring programs as well as advanced systems for the safe storage of bio-samples. Conclusion: Currently on-going biobanks have devoted considerable efforts to managing bio-samples for public purposes. The preceding domestic and foreign biomonitoring programs and biobanks will be great references for constructing biobank facilities and systems for environmental public health in Korea in the future.