• Journal of Digital Convergence
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• v.9 no.2
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• pp.131-140
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• 2011

As the recent advances in network and wireless communications and semiconductor design and process technologies, our computing platform is rapidly shifting from desktop PCs to mobile devices such as UMPC (Ultra Mobile PC), Tablet PC, and Smartphone. Especially, wide-spreading Smartphones allow a new field of application based on location based services available with an user interface called augmented reality (AR). Therefore, this paper introduces an implementation of AR using various OpenAPls on Android Smartphones. In order to utilize enrich user data in real time, the system integrates with location based social network services also with OpenAPI. These APIs enable third-party developers to make use of rich contents of many portal web sites. The prototype was implemented on the real Android phone, Sky Sirius, and the result shows that it can provide an efficient location based service using AR technology without any constraints on mobile devices; in addition, it connects SNS to AR for sharing user data including photos, videos, and messages based on a specific location.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.580-581
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• 2021

There are various Location-Based Services(LBS) that apply GPS technology in mobile devices such as smart-phone and tablet. In this paper, we designed non-face-to-face oriented LBS software in the reality that non-face-to-face services are increasing due to COVID-19. The proposed model searches location information for trading goods or services and utilizes information identified in real time. The proposed scheduling and priority control algorithm provides efficient service allocations and simulation was performed based on web/app to verify this. While commercialized LBS platforms focus on used goods transactions, the designed method is different in that it provides non-face-to-face services and not-direct transactions between individuals. It provides a wide range of transactions and services to users such as small business owners and franchises.

• Journal of The Korean Association of Information Education
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• v.14 no.2
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• pp.165-174
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• 2010

The digital textbook project which embarked by the Ministry of Education, Science and Technology has focused on experiments and practices from the school designated by the government. However the previous research about digital textbook provides static interaction models and teaching-learning models analogous to web-based learning based desktop PC even the framework of the digital textbook is based of Tablet PC. This paper provides learning and teaching models for next generation digital textbook which based digital inking techinques for sketcth interface and AR(augmented reality) interactions between teacher and learner. The proposed method of this paper is applied to educational contents and we found positive effect which is supported by statistical experiments. The results of this study in the future and the future development of digital textbooks in effect will be an effective development plan.

• Journal of Pharmaceutical Investigation
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• v.33 no.1
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• pp.7-14
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• 2003

The PVP-based solid dispersion systems (SDs) containing lovastatin (LOS) and solubilizers (sodium lauryl sulfate, tween 80 and oleic acid) were prepared to enhance dissolution rate of practically water insoluble LOS using solvent evaporation method. Two different organic cosolvents either acetone/ethanol or acetonitrile/ethanol were used for the preparation of SDs. The LOS contents were highly decreased when acetone/ethanol cosolvents were used. The decrease of LOS contents was not caused by acetonitrile or acetone, based on HPLC data. The surface morphology as investigated by scanning electron microscope (SEM) and angle of repose as an index of flowability of SDs were highly dependent on the type and amount of solubilizers used. Based on differential scanning calorimetry (DSC) and X-ray powder diffraction data, the SDs made crystalline LOS into amorphous structure or partially eutectic mixtures. The simultaneous use of the solubilizers in SDs was also useful to increase dissolution rate of LOS in gastric or intestinal fluid. The SDs containing solubilizers reached 76% and 60% in gastric and intestinal fluid, respectively but the commercial tablet gave only less than 4%. These solubilizers in SDs could be also applicable for enhancing dissolution and bioavailability of poorly water-soluble drugs.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.507-519
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• 2015

Along with the rapid diffusion of smart devices, smart learning has been taking place as a main pedagogy in education. Under these drastic changing circumstances, social presence and interaction between learners have been highlighted as key factors in educational research. In this light of rising importance, this study examined the effects of modality and smart device on users' perceived social presence and interaction experience in a smart learning environment. It conducted 2(text based interface vs. audio/video based interface) by 2(smartphone vs. tablet PC) between-subjects experiment. 80 participants were systematically recruited and randomly assigned to four conditions. The findings showed that social presence was higher in audio/video based interface condition than in text based interface condition. Modality also had a positive effect on learner's interaction experience. On the other hand, the effect of smart device is found to be statistically insignificant. Instead, interaction effect existed between modality and device on social presence. The result of this study suggests that the modality and characteristics of device should be considered seriously when designing interface of smart learning contents. The findings in this study provide future studies with heuristic implications by highlighting users' perceived cognition and experience.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.2
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• pp.189-200
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• 2012

With increasing the number of smart device such as Tablet PC, smart phone and netbook, information security which based on smart device in mobile environment have become the issue. It is important to enter a password safety. In various types of mobile devices, because of hardware limitation of device, it is difficult that to equip secondary input device such as keyboard and mouse. Also, a loss of accuracy becomes a problem because input information was entered by touch screen. Because of problem mentioned above it can be predicted to change password scheme text based password scheme to graphical password scheme, graphical password scheme is easy to use and is resistant to shoulder surfing attack. So this paper proposes new graphical password scheme based 5 strokes which are made by decomposed the Korean to defend against shoulder surfing attack.

• Journal of Environmental Health Sciences
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• v.46 no.5
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• pp.495-503
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• 2020

Objective: This study aimed to compare the characteristics of humidifier disinfectant-like products (HD-like products) and humidifier disinfectant products (HD products) and introduce actual cases of the usage of HD-like products in hospitals based on an on-site investigation. Methods: The characteristics, chemical components, and usage of HD-like products (Hichlor or Biospot) and HD products (N-with) containing NaDCC (sodium dichloroisocyanurate) were compared. In the process of conducting the on-site investigation, four hospitals were identified as previously using HD-like products. Each on-site investigation to identify the use of HD-like products was composed of four parts: 1) hospital infection control guidelines, 2) manual for humidifiers in patient's rooms, 3) interviews with nursing staff, infection managers, and purchase managers, 4) searching on the product purchase system. Results: Although HD-like products (Hichlor and Biospot) and HD products (N-with) were sold for different usage purposes, they were all white-colored and coin-shaped foaming tablets with the same chemical component, NaDCC. The manual for using HD-like products and HD products was similar (inserting the tablet in a humidifier container with water). Among the four hospitals, one had used Hichlor in the same manner as HD (N-with) by inserting a tablet in 1L of water in a filled humidifier container and Biospot as a kind of detergent for humidifier container cleaning. Another two hospitals had used Biospot and/or Aniosyme as a kind of detergent for humidifier container cleaning. The other hospital had used unknown product in the same manner as N-with, so we thus assumed it was either an HD products (N-with) or HD-like products (Hichlor, Biospot). Conclusion: This study raises the possibility of the development of adverse health effects similar to exposure to an HD-products when exposed to an HD-like products and the possibility of further use in other medical institutions or multi-use facilities. Therefore, an expansion of the investigation is needed in order to confirm whether there have been similar cases in the past.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.274-279
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• 2012

The objective of this study was to develop oral matrix tablets for the sustained release of vitamin C. In this study hydroxypropyl methylcellulose (HPMC) has been utilized as an excipient, as it is one of the most widely used polymers, for use during long periods of time in formations. The vitamin C tablet formulation depends on the molecular weight and concentration of sustained-delivery in HPMC. Anti-oxidants have been added as a dissolution medium in order to prevent vitamin C degradation in water. The dissolution test was carried out in a distilled water medium, and the release model equation was applied to analyze the vitamin C release pattern. The results demonstrated that the release and lasting power of vitamin C tablets, containing HPMC, lasted for more than 12 h.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.247-250
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• 1984

As a consecutive work on stability for the quality of ginseng products, the sorption properties of red ginseng (RG), red ginseng powder (RGP), and red ginseng powder tablet (RGPT) were studied in order to set the optimum moisture level for them. The levels of moisture at BET monolayer of RGP and RGPT ranged 5.97 to 7.27 % and 4.73 to 5.14 % in wet basis, respectively. Based on these values, the optimum moisture content for both of them would preferably be set at $6.7{\pm}0.7%$ and $4.9{\pm}0.2%$. From the results of storage study on microorganism growth under the maltreated condition, $40^{\circ}C$, and 75% RH, the optimum level of moisture for RG could be extended up to $14.0{\pm}0.5%$, which is much higher than the circulating values of 10.416%.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2762-2767
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• 2011

With increasing use of wireless mobile devices like smartphone and tablet PC, telecommunication companies have been providing the internet service by installing a multitude of access points (AP) in subway stations. Most of these APs use frequency of 2.4 GHz band range and the three telecom providers (SKT, KT, LGT) are using the limited channels within this range without any regulations. The channels within 2.4GHz band are already saturated as the companies are setting up wireless AP even within the subway trains for better service. This can affect other 2.4GHz wireless devices used for other purposes with channel interference, etc. This study has tested and analyzed the effects of the wireless APs installed within the subway stations and trains for the internet service on ZigBee-based sensor network for the intelligent surveillance system of urban transit, which is currently being developed and installed.