• 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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.235-236
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• 2012

국내 최대 규모의 컨테이너 전용 터미널인 K컨테이너터미널이 스마트폰 기능을 터미널운영시스템에 도입하고 있다. "스마트로(SmartLo)"라고 이름 붙여진 모바일 애플리케이션은 컨테이너를 운송하는 화물차 운전기사들이 항만출입을 위한 다양한 정보를 스마트폰에서 확인할 수 있도록 만든 애플리케이션이다. 본 연구에서는 컨테이너터미널 게이트에서 스마트로 모바일 애플리케이션 개발사례를 제시하고자 한다. 스마트로 서비스를 이용함으로써 컨테이너터미널에서는 사전정보 조회를 통하여 외부 정보오류 최소화와 게이트 내 혼잡 해소, 화물에 대한 신속한 반출입을 통한 고객 서비스 증대, 스마트 슬립(e-SLIP)발급으로 슬립 구입비용 절감 등의 효과를 기대할 수 있다. 또한 운송차량은 신속한 게이트 통과로 운송회전율의 향상, 전배 및 셔틀 운송시 화물에 대한 적기 운송이 가능하게 되고, 운송사 입장에서는 효율적인 배차관리가 가능할 것으로 기대하고 있다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.1
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• pp.54-63
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• 2023

In this paper, the effect of corrosion level and crack width on the cohesive strength-slip behavior of corroded steel rebar and concrete interface is conducted. The existing studies mainly focus on the decrease in bond strength with respect to the level of corrosion; there are, however, few studies on the decrease in cohesive strength according to the crack width of the concrete surface due to corrosion. Therefore, in this study, a series of tests for the cohesive strength, slip behavior and mass loss of the reinforcing bar is evaluated at the surface of corroded rebar and concrete. It is found that the tendency to decrease the bond strength is closely related to the crack width rather than the corrosion level. Hence, to determine the degradation performance for the bond strength-slip behavior relation, the occurrence of cracks on the concrete surface can be a suitable index.

• 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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.230-236
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• 2008

In this paper, a model-based stick-slip compensation for the micro-positioning is proposed using an enhanced stick-slip model based on statistical rough surface contact model. The smart structure is comprised with PZT (lead (Pb) zirconia (Zr) Titanate (Ti)) based stack actuator incorporating with the PID (Proportional-Integral-Derivative) control algorithm, mechanical displacement amplifier and positioning devices. For the stick-slip compensation, the elastic-plastic static friction model is used considering the elastic-plastic asperity contact in the rough surfaces statistically. Mathematical model of system for the positioning apparatus was derived from the dynamic behaviors of structural parts. PID feedback control algorithms with the developed stick-slip model as well as feedforward friction compensator are formulated for achieving the accurate positioning performance. Experimental results are provided to show the performances of friction control using the developed positioning apparatus.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.11
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• pp.1134-1142
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• 2008

In this paper, a model-based stick-slip compensation for the micro-positioning is proposed using an enhanced stick-slip model based on statistical rough surface contact model. The smart structure is comprised with PZT(lead (Pb) zirconia(Zr) Titanate(Ti)) based stack actuator incorporating with the PID(proportional-integral-derivative) control algorithm, mechanical displacement amplifier and positioning devices. For the stick-slip compensation, the elastic-plastic static friction model is used considering the elastic-plastic asperity contact in the rough surfaces statistically. Mathematical model of system for the positioning apparatus was derived from the dynamic behaviors of structural parts. PID feedback control algorithms with the developed stick-slip model as well as feedforward friction compensator are formulated for achieving the accurate positioning performance. Experimental results are provided to show the performances of friction control using the developed positioning apparatus.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.663-668
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• 2022

As the number of people who experience sleep disorders is increasily growing, users' desire to improve their sleep quality has also increased. Acoordingly, the 'Sleeptech' market is showing a steady growth. This study designs and proposes a system after consideration of existing related research that can help modern people overcome sleep disorders, which is based on the necessity for customized sleep hygien service. This system analyzes user's sleep data collected through smartphone built-in sensors to calculate sleep patterns, provides customized sleep hygiene-based solutions to users through collaborative filtering, and provides an environment suitable for sleep through the automatic control of IoT devices. This method of using sleep data is expected to contribute to the improvement of the quality of life of modern people suffering from sleep disorders, which results from expansion to Sleeptech market as well as improvement of users' sleep habits.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.873-880
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• 2011

As environmental pollution, global warming, and exhaustion of fossil fuel become global issue recently, there has been strong research motivation to develop green energy technology. Along the same line of motivation, some research efforts have been put into the development of environment-friendly bicycle equipped with various smart energy technologies to increase the usability of the bicycle as short-distance transportation. Among the technologies related with new generation bicycle, PAS (power assist system) is one of the most important systems that are essential in efficiently integrating human power and the electrical power supplied by electric motor driven by battery. In this paper, a novel torque sensor technology which is core component for PAS is proposed. Unlike existing technologies, strain gauges are attached to rear shaft directly under the hub bearings, which eliminates the requirement of slip-ring, Furthermore, the sensor is able to not only measure the torque transmitted to driving axle by human but also estimate the position of the gear to which the chain is currently engaged.

• Science of Emotion and Sensibility
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• v.22 no.1
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• pp.89-100
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• 2019

Sleep apnea, a medical condition associated with a variety of complications, is generally monitored by standard sleep polysomnography, which is expensive and uncomfortable. To overcome these limitations, this study proposes an unconstrained wearable monitoring system with stretch-fiber sensors that integrate with the wearer's clothing. The system allows patients to undergo examinations in a familiar environment while minimizing the occurrence of skin allergies caused by adhesive tools. As smart clothing for adult males with sleep apnea, long-sleeved T-shirts embedding fibrous sensors were developed, enabling real-time monitoring of the patients' breathing rate, oxygen saturation, and airflow as sleep apnea diagnostic indicators. The gauge factor was measured as 20.3 in sample 4. The maximum breathing intake, measured during three large breaths, was 2048 ml. the oxygen saturation was measured before and during breath-holding. The oxygen saturation change was 69.45%, showing a minimum measurable oxygen saturation of 70%. After washing the garment, the gauge factor reduced only to 18.0, confirming the durability of the proposed system. The wearable sleep apnea monitoring smart clothes are readily available in the home and can measure three indicators of sleep apnea: respiration rate, breathing flow and oxygen saturation.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.3
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• pp.77-84
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• 2021

In this study, flexural tests of prestressed high strength spun concrete (PHC) piles reinforced with infilled concrete and longitudinal rebars were conducted, where the longitudinal rebar ratio and the presence of sludge formed on the inner surface of PHC pile were set as key test variables. A total of six PHC pile specimens were manufactured, and their flexural behaviors including failure mode, crack pattern, longitudinal strain distribution in a section and end slip between external PHC pile and infilled concrete were measured and discussed in detail. The test results revealed that the flexural stiffness and strength increased as the longitudinal rebar ratio became larger, and that the sludge formed on the inner surface of PHC pile did not show any detrimental effect on the flexural performance. In addition to the experimental approach, this study presents a nonlinear flexural analysis model considering compatibility conditions and strain and stress distributions of the PHC piles and infilled concrete. The rationality of the nonlinear flexural analysis model was verified by comparing it with test results, and it appeared that the proposed model well evaluated the flexural behavior of PHC piles reinforced with infilled concrete and longitudinal rebars with a good accuracy.