• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.416-422
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• 2017

The robot control with safety consideration is required since robots and human work together in the same space more frequently in these days. For safety, robots must have compliance to human force and robust tracking performance with high impednace for the nonhuman disturbances. The novel idea is proposed to achieve the compliance and high impedance with one controller structure. For the compliance, the ISMC(Integral Sliding Mode Control) and HDOB(Human Disturbance Observer) The human force is identified by using the human band pass filter and its output is sent to the sliding surface. The sliding mode dynamic is affected by human disturbance and the compliance for human is achieved. The disturbances besides human frequencies are decoupled by the ISMC and the robust tracking is achieved. The additional LDOB(Low Frequency Disturbance Observer) decreases the maxim nonlinear gain and leads low chattering. The introduction of human disturbance into the sliding mode dynamic is the main novel idea of this paper.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.5
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• pp.25-34
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• 2021

Increase in avian species richness is one of the important issues of urban biodiversity policies, since it can promote diverse ecosystem services such as seed dispersal, education, and pollination. However, though human disturbance can significantly affect avian species richness, there are limited studies on the way to reflect the dynamics of floating population. Therefore, this study analyzed the spatial relationship between avian species richness, floating population, and vegetation cover using telecommunications information to identify the areas that requiring targeted monitoring and restoration action. Bivariate Local Moran's I was applied to identify LISA cluster map that showing representative biotopes, which reflect significant spatial relationship between species richness and population distribution. Edge density and distribution of ndvi were identified for evaluating relative adequacy of selected biotopes to strengthen the robust biodiversity network. This study offers insight to consider human disturbance in spatial context using innovative big data to increase the effectiveness of urban biodiversity measures.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.7
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• pp.615-620
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• 2015

DOB (Disturbance Observer) is an useful control method for estimating the disturbance applied to dynamic systems. Disturbance observer can be used to implement a robust control system to generate a control input for rejecting the disturbance, and it can be also used to estimate the disturbance to obtain information. The system that uses disturbance estimation is investigated for high performance control such as automatic door systems, walking robot and electric power steering system in vehicles. In this paper, a novel disturbance observer which is called disturbance and current observer for estimating load torque in the motor system is proposed. The difference between the DOB for disturbance rejection and DCOB is mathematically verified. Current and angular velocity are required for estimating the load torque of the motor in DOB. However, the DCOB can estimate load torque and current without current sensor. DCOB is designed based on modeling of the motor system. Appropriate Q-filter is selected and the applicability of DCOB is verified by simulation. The estimated disturbance and current of the electric motor can be verified without current sensor, as experiments of the actual motor system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.297-303
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• 2015

We propose a disturbance observer(DOB) based feedback linearization control to improve position tracking performance in the presence of disturbance. The proposed method consists of a disturbance observer and a feedback linearization controller. The disturbance observer is designed to estimate the load force disturbance in electro-hydraulic systems. An auxiliary state variable is proposed in order to avoid amplification of the measurement noises in the disturbance observer. Using the estimated disturbance enables the Electro-hydraulic servo systems(EHS) dynamics to be changed into feedback linearization from. In order to compensate for the disturbance and to track the desired position, the feedback linearization based controller is proposed. The proposed method has a simple structure which can easily be implemented in practice. As a result, the proposed method improves the position tracking performance in the presence of disturbance. Its performance is validated via simulations.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.155-170
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• 2016

This study established the definition of invasive disturbance species for a sustainable management and biodiversity, and derived the influence factors caused by the species. To define the species, the paper reviewed similar words such as alien species and invasive species, using standard definitions. Also reviewed the results of recent research on the factors of the species. The paper defined the invasive disturbance species as an species whose establishment and spread threaten ecosystems, habitats or species with economic or environmental harm including native and non-native. Through the reviews, The factors were classified as geographic (altitude, slope, and soil, etc.), climate (temperature, precipitation, climate change, etc.) and, anthropogenic (land use, population, road, and human activity, etc.), and species & vegetation structure (species property, local-species richness, and canopy, etc.). Especially, human activity such as urbanization and highways may be associated with both higher disturbance and higher propagule pressure. In the further study, it is required development of mitigation strategies and vegetation structure model against invasive disturbance species in urban forest based on this study.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.9
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• pp.960-966
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• 2009

The World Health Organization(WHO) has reported the sleep disturbance as one of the adverse effects of noise. And the effect of combined noise sources on human have been investigated because community noises are seldom heard and are concurrent. Therefore, the effects of combined noise source and its S/N ratio on sleep disturbance were investigated; as a single noise source, road traffic noise was selected, and construction and movie noise were combined with road traffic noise. Tests for sleep disturbance were conducted in bedrooms and the effect on each subjects' sleep was evaluated by questionnaire. The results showed that the rate of awakening increased slightly only when the SPL of construction noise was 10 dB higher than that of road traffic noise. It was also found that the sleep disturbance was affected by the type of combined noise sources and its S/N ratio.

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.4
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• pp.31-36
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• 2011

Smart Door(SD) is a human friendly power-assisted door system for passenger car doors. It offers comfort and safety to passengers and drivers by supplying additional power. In this study, dynamic system model and the equation of motion derivation are derived. And we propose the disturbance observer based collision detection algorithm for safety when opening the door. A disturbance caused by collision has a fast response compared to a friction, uncertainties and so on. The main idea this study is to estimate a variation of disturbance for stably and effectively detecting a collision. In order to evaluate a performance of collision detection, an experiment set up is constructed. The experimental results validate the usefulness of the proposed collision detection algorithm.

• Journal of Ecology and Environment
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• v.30 no.1
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• pp.69-73
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• 2007

The sources and the frequency of disturbances and the responses of shorebirds to disturbances were studied at four roosting sites on Ganghwa Island and Yeongjong Island. The mean frequency of disturbance to roosting shorebirds was 2.7 per hour. Human activities contributed to the disturbance in 65% of all cases. Disturbance frequencies in saltpans were higher than those in the upper tidal zone, fishponds and salt marshes. Response patterns of shorebirds to disturbances were associated with the source of the disturbance. Disturbance caused shorebirds to change their behavior and to reduce roosting time at their roosting sites. Four patterns of responses by roosting shorebirds to disturbance were found, including: (1) leaving the roosts, (2) changing their location within the site, (3) leaving and returning, and (4) remaining in place. In the latter three response patterns, the birds tended to remain in their initial roosting sites, in contrast with the leaving pattern, which involved departing from the roosting area. Factors affecting these response patterns were time from high tide and time of day. When the time from high tide was greater, and the time of day was later, more birds stayed at the roost. The absence of sufficient alternative roosts in the study areas forced the birds to choose between tolerating the current disturbance, or moving to distant roosts.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.321-328
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• 2002

In order to provide the basic information for restoration of vegetation, conservation of rare species and maintenance of biodiversity, changes of site factors and vegetation by human trampling disturbance were investigated at the subalpine zone near the peak of Mt. Sorak in Korea. The destructed vegetation was found mainly in the southern parts with gentle slope in this study area. Height and coverage of vegetation and the species diversity decreased, and the community structure depended on trampling strength. Soil moisture, organic matter contents and litter thickness in the site with destructed vegetation by human trampling showed lower values than in the undisturbed site. Soil depth decreased, and gravel exposure on the ground surface increased by soil erosion responded to trampling strength.

• The Journal of Korean Medical History
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• v.27 no.2
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• pp.99-120
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• 2014

Purpose : There are two types of sleep disturbance: inability to sleep (不眠) and somnolence (多眠). This study is to examine treatments of the two types of sleep disturbance in the Books of Cold Damage and how those theories were established and formed. Methods : 1. Verses including the words related to inability to sleep and somnolence were extracted from "Treatise on Cold Damage Diseases" (傷寒論). 2. Among the Books on Cold Damages that are classified according to the symptoms, 17 books with contents related to inability to sleep and somnolence were selected to collect and classify data in three perspectives: mechanism of disease (病機), method of treatment (治法) and disease pattern (病證). 3. Data collected through the above methods were compared and diagramed. Results & Conclusions : 1. On Cold Damage, inability to sleep is mostly rooted when human body lacks yin energy while having excessive yang energy (陽盛陰虛) due to fire and heat (火熱). The reason could be misuse of perspiration inducing method (汗法) or purgation (下法) on the doctors' part. 2. On Cold Damage, somnolence is rooted when pathogen (邪氣) is spread to yin meridians (陰經) and the human body lacks yang while having excessive yin energy (陰盛陽虛) or when heat (熱邪) is invaded into interior parts (裏部). 3. Many scholars of Cold Damage in later periods had copied the "Treatise on Cold Damage Diseases" for treatments of sleep disturbance but many others have applied the verses from "Treatise on Cold Damage Diseases" or added new treatments. Do jeol-am (陶節庵) and Wang Geung-dang (王肯堂) particularly had deep understanding on "Treatise on Cold Damage Diseases" and utilized the content freely or suggested new remedies because they had thorough knowledge on relating formula as well.