• Proceedings of the Korean Information Science Society Conference
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• 2007.06b
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• pp.441-444
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• 2007

본 논문에서는 객체기반 IP 스토리지를 이용하여 모바일 기기에서 멀티미디어 콘텐츠 재생에 적합한 저전력 객체기반 모바일 스토리지 시스템 구조를 제안한다. 멀티미디어 콘텐츠의 재생 성능을 높이기 위해 모바일 단말 측 OSD 계층에 버퍼 캐시(buffer cache)와 선반입(prefetch) 기능을 추가한다. 그리고 모바일 단말의 WLAN 전력제어를 통하여 WLAN이 가능한 한 오랜 시간 동안 Sleep 상태 또는 Power Off 상태에 있을 수 있도록 하여 전력의 소비를 줄인다. 본 연구에서는 캐시 및 선반입 기능을 위해 버퍼 캐시관리자(buffer cache manager)와 선반입 관리자(prefetch manager)를 설계하였고, WLAN 전력관리 기능을 위해 WLAN 관리자(WLAN manager)를 설계하였다.

• Journal of Fashion Business
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• v.23 no.1
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• pp.14-24
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• 2019

Various types of functional bedding for inducing and maintaining sleep, are developed and launched with the importance of improving health through sleep emphasized currently. The purpose of this study is to examine development status and direction of functional bedding in the $4^{th}$ Industrial Revolution era, through systematic classification of elements of IoT-based smart bedding cases actively developed as functional bedding at home and abroad. Through previous research, literature and Internet data, characteristics and functional extension of smart bedding and the background of smart bed development was analyzed. And it was analyzed that smart bedding pursues recent functionalism and convergence of physical and digital concept such as IoT or AI, and also mental value to improve sleep quality. As bedroom where smart bedding place in has the private and limited characteristics and users are in sleep-conscious, that hard to ensure power and discomfort in carrying are moderated and the aesthetic elements are not very important, and that the smart bedding performance while sleeping were affected on developmental background. Based on CES case study and analysis on how smart beds are functionally expanded from conventional bedding, smart beds have gained information through digital sensing, and common properties that can be controlled anytime, anywhere, using a smart phone. Some set up the right environment and pose, while others stimulate nerves directly as active intervention. It is expected that smart bedding will be developed to cure user's body and mind, through active intervention when sleeping.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.474-477
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• 2002

Hearing loss caused by exposure to industrial machine noise results in devastating disability that is mostly preventable. And recent researches indicate that the noise may also induce hypertension and cardiovascular disease. In addition the sleep polygraph provides many indicators of sleep disturbance by the noise. In this paper we make an analysis on ball bearing machine noise, a kind of the industrial noise. The analysis of Its power spectrum is based on FFT(Fast Fourier Transform). And then the spectral results of the noise are compared with that of the spectrum for an auditory signal. The signal is measured from the pronunciation of two Koreans. Finally we suggest the most important stratagem to prevent the noise for worker's health and efficiency.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.3
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• pp.137-143
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• 2017

This paper presents a smart parking guidance system based on IoT car-stoppers. The car-stopper embedding an IoT sensor module has the advantage of easy installation compared to conventional parking sensors buried in ground. The parking status data are transferred to the IoT gateway by the sequential point-to-point communication between the car-stoppers. The data transferred from the IoT gateway are stored in the web server, and parking spaces can be monitored remotely through the Android app in a smart device. An active/sleep cycle method using a watch dog timer is employed to reduce the power consumption of the battery powered car-stopper. The power consumption of the car-stopper is measured to be 80 and 25 mW at the active and sleep mode, respectively. A configuration of ultra-low-power IoT sensor module is proposed to minimize the power consumption in the sleep mode. The operation of the implemented system has been verified in a real-world parking lot.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.378-387
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• 2018

With the advent of the fourth industrial revolution in recent years, the field of health care services is getting attention again. Accordingly, personalized medical systems through smart products are emerging in various forms. With the use of wearable tech and sensor system, health management and monitoring can be done anytime, anywhere without help of others. However, healthcare services for pregnant women are very scarce. Due to the low fertility rate the number of obstetrics and gynecology is decreasing and as a result, environment surrounding the uncomfortable pregnant women is getting worse. Pregnant women are unable to take a comfortable sleeping posture due to pregnancy. Various environmental factors such as noise, temperature and humidity decrease the quality of sleeping of pregnant women and hinder happy preaching. The purpose of this study is to develop a UI design that can manage sleeping by providing good sleeping posture information and improved sleeping environment for the health of pregnant women. We expect to apply the sensor technology of the 4th industrial age to maximize the sleep quality and quality of life of expectant mothers.

• Journal of Communications and Networks
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• v.14 no.1
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• pp.40-50
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• 2012

The Berkeley-medium access control (B-MAC) is a lightweight, configurable and asynchronous duty cycle medium access control (MAC) protocol in wireless sensor networks. This article presents an analytic modelling of single-hop B-MAC protocol under a Poisson traffic assumption.Our model considers important B-MAC parameters such as the sleep cycle, the two stage backoff mechanism, and the extended preamble. The service delay of an arriving packet and the energy consumption are calculated by an iterative method. The simulation results verify that the proposed analytic model can accurately estimate the performance of single-hop B-MAC with different operating environments.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.4
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• pp.248-256
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• 2009

In this paper, under saturated traffic condition in a single-hop wireless sensor network, we present an analytic model that evaluates the performance of asynchronous MAC protocol which uses a preamble technique. Our model considers the impact of several important factors such as sleep cycle, the backoff mechanism and the number of contending nodes. After obtaining the cumulative backoff time of a sending node and expected delay of a receiving node, an iterative algorithm is presented for calculating the performance measures such as expected energy consumption usage per packet and latency. Simulation results show that the proposed analytic model can accurately estimate the performance measures under saturated traffic conditions.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.95-98
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• 2020

최근 스마트 홈에서 슬립테크를 제어할 수 있는 어플리케이션 개발 및 연구의 필요성이 높아지고 있다. 기존 스마트 홈 제어 어플리케이션들은 텍스트 형식의 UI, 직관적인 정보 제공의 부재, 스마트 스위치 수준의 서비스 제공 등의 문제점을 가지고 있다. 이러한 문제점을 개선하기 위해 본 논문에서는 증강현실과 3D 모델링을 통해 스마트 홈을 보다 직관적이고 편리하게 사용할 수 있는 슬립테크 제어 방법을 제안한다.

• Journal of the Speleological Society of Korea
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• no.95
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• pp.15-21
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• 2009

Global village warming and carbon dioxide CO2 gas, and the human efforts for their healing and necessary alternative technology would be much more difficult things than that of making necessary funds and efforts to lay to sleep angry nature on the earth. The limited natural resources of fossil fuel would be dried up in several decades, and the intensity of diplomatic negotiations for natural resource guarantee among countries may be showed looking alike an war. The drain of fossil fuel called a new word of alternative policy like an environment-friendly green-growth, and the solar-cell and lighting technology for the solar energy applications were developed still more repeatedly day by day from oil lantern to LED high-tech illumination in great economy. Therefore, it was studied that the low-carbon green-growth illumination technology in cave applications with SOLAR-LED system which was produced and unified in connection with solar-cell and LED from the semiconductor production technology, and it was also clarified in necessary with useful cave lighting in heatless and with no photosynthesis of plant production in underground space.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.423-438
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• 2010

Wireless smart sensors enable new approaches to improve structural health monitoring (SHM) practices through the use of distributed data processing. Such an approach is scalable to the large number of sensor nodes required for high-fidelity modal analysis and damage detection. While much of the technology associated with smart sensors has been available for nearly a decade, there have been limited numbers of fulls-cale implementations due to the lack of critical hardware and software elements. This research develops a flexible wireless smart sensor framework for full-scale, autonomous SHM that integrates the necessary software and hardware while addressing key implementation requirements. The Imote2 smart sensor platform is employed, providing the computation and communication resources that support demanding sensor network applications such as SHM of civil infrastructure. A multi-metric Imote2 sensor board with onboard signal processing specifically designed for SHM applications has been designed and validated. The framework software is based on a service-oriented architecture that is modular, reusable and extensible, thus allowing engineers to more readily realize the potential of smart sensor technology. Flexible network management software combines a sleep/wake cycle for enhanced power efficiency with threshold detection for triggering network wide operations such as synchronized sensing or decentralized modal analysis. The framework developed in this research has been validated on a full-scale a cable-stayed bridge in South Korea.