• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.19 no.3
• /
• pp.587-595
• /
• 2015

A by-pass path in wireless sensor networks is the alternative path which be able to forward data when a routing path is being broken. One reason of depleting energy is occurred by the path. The method for solving prior to addressed the problem is proposed. However, this method may deplete radio resource. The best path has advantage that network lifetime of sensor nodes is prolonged; on the contrary, in order to maintain the best path it have to share their information between the entire nodes. In this paper, we propose the best path searching algorithm in the distributed three dimensional sensor networks. Through the neighboring informations sharing in the proposed method, the proposed algorithm can decide the best k-path as well as the extension of network lifetime.

• Journal of the Korean Ceramic Society
• /
• v.41 no.4
• /
• pp.297-301
• /
• 2004

Nano-sized mullite (3Al$_2$O$_3$$.$2SiO$_2$) colloids were prepared by use of the spray combustion method. For combustion reaction, Al(NO$_3$)$_3$$.$9$H_2O$, and CH$_{6}$N$_4$O were used as an oxidizer and a fuel respectively, and then colloidal silica was also added as 2SiO$_2$source for mullite. The temperature of the reaction chamber was kept at 80$0^{\circ}C$ to initiate the ignition of droplets of the mixed precursors. For preventing droplet coagulation, the droplet number concentration was reduced using the metal screen filter, and the residence time of aerosol was kept at 2.5 seconds for laminar flow. The synthesized colloidal particles had an uniform spherical shape with 130 nanometer size and the crystalline phase showed the mullite with stoichiometry in the observations of XRD and TEM.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.740-743
• /
• 2012

The initial role of the operating system acts as an intermediary between the computer and the user, and, hardware and process management, and the convenience of your computer system is to use. Of these operating systems as well as servers and personal computers, smartphones and tablet mounted on mobile devices such as mobile operating system was born. Mobile Operating System has been expanded a TV or Car Area that built into a simple embedded operating system, is emergence of a variety of devices, cloud services, combined with the desire of users due to the high built-in simple embedded operating system that was working on a TV or a car is expanding to the area. The reason for the emergence of a variety of devices, cloud services, combined with the desire of users is high. In this paper, the mobile operating system, N-Screen, Smart TV to find out about and through the analysis of the major smart TV, the future Find out about trends in the mobile operating system.

• Convergence Security Journal
• /
• v.12 no.3
• /
• pp.123-129
• /
• 2012

Due to the high digital technology, various devices such as TV, PC, smartphone, and pad computer are connected to each other using internet and under the circumstance internet services of which the running platforms are mainly PC become "N-screenlized" by extending their service platform to non-PC devices. As a digital TV has outstanding features of being the most influential device in the living room and having the wide spectrum of users, several internet services has been ported on the digital TV platform (in the form of data services) in order to enhance their brand powers. Most of the services, however, failed to get a satisfactory results as the data services are defeated by the broadcasting contents in the competition for the viewer's interests. In the paper, the design guidelines that make data services not to compete with the broadcasting contents are proposed and a prototype of a data service that accommodates the guidelines is introduced. The prototype, called "TV ideal-type world-cup", does not disturb a viewer's watching broadcast contents and channel-changing behavior while it is running and its service flow is designed for a viewer to achieve the goal of service in a few minutes so that the viewer can enjoy the service in a commercial period.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.5
• /
• pp.1077-1082
• /
• 2012

User interface model technology can apply UI based on a user's choice. Recently, researches about th interface for the user's convenience have been actively made. For this, in W3C, various researches are ongoing in order to provide UI adjust service based on N-Screen service, consistent service provision, and the user's preference. In this paper, we study the model-based interface technology, which is fundamental to develop UI for the user's convenience. For this we study the verification process by analyzing elements of the user interface technology, analyzing the standards of the UI, and finding improvements for the MBUI standard. This will be used in order to secure the technology for web-application measures and to apply next-generation web-application.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.19 no.2
• /
• pp.55-69
• /
• 2011

Use of disposer at the kitchens of Korean apartments is inevitable in treating their foodwaste having a water content of more than 80%. Also we have to ensure that this extra disposer-foodwaste BOD loadings be treated properly by installing/operating a pre-treatment system before this wastewater enters public sewer system. However, the degree of BOD removal should not be excessive since a BOD/N ratio higher than 5 is required for removing N/P at a municipal wastewater treatment plant. The removal of BOD/N in the pretreatment system rather than BOD alone can be an alternative solution in solving this problem. The particles separated by sedimentation, screen or packed-bed can be anaerobically digested at apartment sites to generate biogas that can be used for simple digester heating and to generate volatile fatty acids (VFAs) for nitrogen removal. We suggest that Korean government grants a temporary license (say for 5 years) to foodwaste treatment companies in collaboration with apartment construction companies which may do business and develop various kinds of disposer-foodwaste treatment systems in diverse wastewater discharge systems of Korean apartments.

• Journal of Bio-Environment Control
• /
• v.12 no.1
• /
• pp.45-53
• /
• 2003

The object of this study was to develop the control technology of daily integral photosynthetic photon flux (PPF) by the artificial lighting and shading screen in greenhouse. The shading time needed to get the target PPF by using two types of shading screens having shading ratio of 55% and 85% was analyzed. The results showed the shading ratio of screen to be installed in greenhouse should be different depending on the amount of target PPF to be controlled. The PPF control experiment by using the 55% shading screen in July and August showed that the maximum difference between measured and calculated value was about 5 mol$.$ $m^{-2}$ $.$ $d^{-1}$ in no shading condition. This difference is satisfactory result because the daily integral PPF is quite different depending on the weather condition. The simulation result about PPF distribution pattern shortened the time needed to find the proper arrangement of artificial lightings in greenhouse. But the further study was required to find the supplemental lighting arrangement to be able to provide the exactly uniform distribution of target light intensity. The supplemental irradiation time needed to acquire the target daily integral PPF for different supplemental light intensities, weather conditions, and months was analyzed. The result showed that the supplemental light intensity should be decided depending on the amount of target PPF to be controlled. The result of PPF control experiment conducted by using 55% shading screen and 300 $\mu$mol$.$ $m^{-2}$ $.$ $s^{-1}$ supplemental light intensity from the end of May to the beginning of June showed that the maximum difference between target and measured value was about 3 mol$.$ $d^{-1}$ $.$ $m^{-2}$ . If we consider that the difference of the daily integral PPF depending on weather condition was the maximum 30 mol$.$ $m^{-2}$ $.$ $d^{-l}$, the control effect was acceptable. Although the result of this study was the PPF control technology to grow lettuce, the data and control method obtained could be employed for other crop production.n.

• Journal of Korea Water Resources Association
• /
• v.51 no.2
• /
• pp.151-163
• /
• 2018

The objective of this study was to estimate LOADEST (LOAD Estimator) coefficients for simulating pollutant loads in ungauged watersheds. Regression models of LOADEST were used to simulate pollutant loads, and the multiple linear regression (MLR) was used for coefficients estimation on watershed characteristics. The fifth and third model of LOADEST were selected to simulate T-N (Total-Nitrogen) and T-P (Total-Phosphorous) loads, respectively. The results and statistics indicated that regression models based on LOADEST simulated pollutant loads reasonably and model coefficients were reliable. However, the results also indicated that LOADEST underestimated pollutant loads and had a bias. For this reason, simulated loads were corrected the bias by a quantile mapping method in this study. Corrected loads indicated that the bias correction was effective. Using multiple regression analysis, a coefficient estimation methods according to the watershed characteristic were developed. Coefficients which calculated by MLR were used in models. The simulated result and statistics indicated that MLR estimated the model coefficients reasonably. Regression models developed in this study would help simulate pollutant loads for ungauged watersheds and be a screen model for policy decision.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.304-304
• /
• 2010

최근 생활에 편리하며 휴대하기 좋은 전자기기들이 개발되고 있다. 휴대폰이나 MP3와 같은 전자기기들은 거의 필수품이라고 할 정도로 우리의 일상생활에 근접하여 있다. 그 종 대표적으로 휴대폰의 종류로 스마트폰과 같은 터치스크린을 이용한 사례는 점차 상승하고 있으며 시간이 지날수록 그 수요는 더욱 많아지고 있다. 때문에 몰입감 제공을 위하여 햅틱장치의 채용이 일반화 되고 있다. 햅틱장치란 가상환경이나 원거리에 있는 환경과 사용자가 상호 작용할 때 사용자에게 촉감이나 힘의 정보를 전달하여 주는 장치로 진동 및 회동 저항에 의해 사용자로 하여금 촉감들 느낄 수 있도록 하는 장치를 뜻한다. 즉, 현실감을 전달을 중점으로 하는 햅틱장치는 빠른 응답 속도와, 진동의 주파수와 크기는 독립적으로 제어가 가능해야 하며 기계적 수용기들을 직접적으로 자극할 수 있어야 한다. 하지만 모바일 햅틱장치의 경우 크기 및 소비전력의 문제로 모든 스펙을 만족하기에는 어려워 좀 더 한정적인 느낌을 제공할 수 없다. 현재까지 모바일 장치에서 햅틱 피드백을 위하여 진동모터나, 솔레노이드, 압전 액츄에이터 등이 많이 사용되어 지고 있다. 그 중 압전 액츄에이터는 입력에너지를 기계적 출력에너지로 변환되는 효과를 이용 한 것으로 압력 센서, 초음파 센서 등 많은 분야에서 응용되고 있으며 변위 범위는 작지만, 크기가 매우 작고 변위 정밀도가 높으며 발생력과 응답속도가 빠르다는 장점이 존재한다. 이를 이용한 햅틱 압전 엑츄에이터의 제작에 사용되는 압전 세라믹스는 높은 전기적 특성을 가질수록 더 졸은 효율을 가지며 이로 인하여 보다 좋은 전기적 특성을 가지는 압전 세라믹스를 필요로 한다. 현재 많이 사용되는 PZT계 세라믹스는 우수한 전기적 특성으로 많이 사용되고 있지만 Pb의 유독성으로 인한 환경문제로 Pb가 포함된 제품을 제한하고 있어 현재 Lead-free의 연구가 이루어지고 있다. Lead-free중 Ba$(Ti_{0.8}Zr_{0.2})O_3$(BZT)는 PZT계 세라믹스를 대체할 차세대 압전 재료로 주목받고 있다. 일반적으로 Lead-free의 압전계수($d_{33}$=100~300pC/N)는 비교적 낮은 값을 보이지만 BZT의 압전계수(BZT $d_{33}$~620pC/N)는 PZT계 세라믹스의 압전계수($d_{33}$=500~600pC/N)와 비교하여 부족하지 않은 압전계수를 보여주며 PZT를 대체할 재료로 주목받고 있다. 본 실험은 햅틱 압전 엑츄에이터용 무연 압전세라믹스의 제작을 위하여 Ba$(Ti_{0.8}Zr_{0.2})O_3-(Ba_{0.7}Ca_{0.3})-TiO_3$(BZT -BCT)의 조성으로 유전 및 압전 특성을 조사하였다.

• Journal of Korea Society of Industrial Information Systems
• /
• v.17 no.1
• /
• pp.47-62
• /
• 2012

To propagate clinical disease management service, there should be built a ecosystem where service developers, service providers, device suppliers closely cooperate for u-Health platform. However, most u-Health platform is difficult to build an effective ecosystem due to the lack of secure and effective PHR(Personal Health Record) management, the lack of personalized and intelligent service, difficulties of N-screen service. To solve these problems we suggest the CDMP(Chronic Disease Management Platform) architecture. The CDMP is a software platform that provides the core functions to develop the chronic disease management services and performs a hub function for the link and integration rbetween various services and systems. CDMP is SOA based platform that enables a provision of reusability, expansibility and it provides open API where everybody can share information, contents and services easily. CDMP supports the multi platform system foN-screen service and the self management functions via SNS. In this paper, we design and implement the CDMP including PHR service based on hybrid data model for privacy preservation. Experiment results prove the effectiveness of hybrid model-based PHR service.