• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.137-144
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• 2004

ECG signals are often contaminated with high-frequency noise such as muscle artifact, power line interference, and others. In the ECG signal processing, especially during a pre-processing stage, numerous noise removal techniques have been used to reduce these high-frequency noise without much distorting the original signal. This paper proposes a new type of digital filter with a continuously variable cutoff frequency to improve the signal quality This filter consists of a cutoff frequency controller (CFC) and variable cutoff frequency lowpass filter (VCF-LPF). From the noisy input ECG signal, CFC produces a cutoff frequency control signal using the signal slew rate. We implemented VCF-LPF based on two new filter design methods called convex combination filter (CCF) and weight interpolation fille. (WIF). These two methods allow us to change the cutoff frequency of a lowpass filter In an arbitrary fine step. VCF-LPF shows an excellent noise reduction capability for the entire time segment of ECG excluding the rising and falling edge of a very sharp QRS complex. We found VCF-LPF very useful and practical for better signal visualization and probably for better ECG interpretation. We expect this new digital filter will find its applications especially in a home health management system where the measured ECG signals are easily contaminated with high-frequency noises .

• Korean Security Journal
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• no.20
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• pp.119-140
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• 2009

It seems that security police's business to secure safety of state and citizens has existed since the mankind began to create a community. State was not fully responsible for such security business from the beginning. The business was carried out autonomously by the private sector for a long period. However, as the state system had been strengthened, the public sector absorbed the function. But in the modern society where various risks exist, safety of society could not be guaranteed only by public police. Accordingly, cooperation with the private sector is indispensable. In the limit of public police, autonomous organization of security companies and general citizens is expanding its scope. As a result, they should exercise partnership as a tripod to build social safety net. Security police failed to secure manpower exclusively responsible for security, despite various businesses and excessive mobilization. Accordingly, their professionalism and ability to cope with crisis are being questioned. In particular, efficiency of security police is becoming a more urgent issue in an era of international terrorism. Private sector can be classified into security companies and private autonomous organization. In case of security companies, the problem is quality and business ability of guards compared to a rapid external growth such as quantitative expansion and advancement into various businesses. In terms of pure private activity, the necessity of understanding of public police activity and conditions for organizational and continuous activity should be prepared. To tide over such problems and effectively achieve the common goal, changes in the method of employment, new establishment of security police department, and strengthening of professionalism and crisis management ability are necessary in the public police sector. In case of security companies, improvement of relations with public police through joint education, strengthening of business ability and activation of business cooperation through these matters are necessary. To maximize activity of pure private sector, it needs to establish reserve police, manage such private autonomous organization and bolster publicity with citizens.

• Journal of radiological science and technology
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• v.37 no.2
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• pp.75-84
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• 2014

In this study, we surveyed the current status, satisfaction and demand of radiologic technologist continuing education for 93 radiologic technologists who participated in the continuing education. To understand the current status and general evaluation and to find out the improvement direction, survey was conducted on 3 categories: participation, satisfaction and demand of continuing education. In addition, we analyzed the continuing education implementation status and the management system by collecting related regulations. As a result, the education completion rates of radiologic technologists from 2010 to 2012 were respectively 42.6%, 43.4% and 34.2%; the rates were similar to other medical technician's average education completion rates. According to the survey, in case of participation, the most frequent answer was 'more than five times less than 10 times per year' with 48.4% and in satisfaction section, the most common answer was 'Average(3)' with 34.4%. In demand of continuing education section, 32.8% of the respondents chose 'Clinical skill training in major field'. In the results of this research, continuing education needs to be managed in the direction of helping radiologists improve their personal ability and self development. Furthermore, to meet the demand of radiologists, the quality of continuing education should be improved to satisfy the educatee.

• Journal of Technology Innovation
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• v.20 no.2
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• pp.109-134
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• 2012

In this era of globalization and fierce competition, R&D is an essential part of corporate development strategy. Accordingly, much effort has been devoted to identify and verify best practices for successful R&D and to improve R&D processes. Nevertheless, there is still lack of a comprehensive framework for assessing the quality of R&D process, which can be used as a step-by-step guide for process improvement. Therefore, this study purposes to develop a framework for assessing R&D process based on the concept of CMMI, which is a process improvement approach that defines the essential elements of effective processes. In particular, we suggest three types of R&D process-new product development, new service creation and new technology creation-and then develop a customized framework for them. For this purpose, we firstly investigated the characteristics of R&D activities for each type of process and identify its base practices from an extensive literature review. Then, the CMMI approach was adopted and modified to suit the R&D process. Finally, an illustrative example was provided to demonstrate the assessment process and a prototype web-based assessment system was suggested. Research findings will help understand the characteristics of different types of R&D process and provide a customized guidelines for R&D process assessment and improvement.

• Journal of Wetlands Research
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• v.18 no.3
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• pp.313-323
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• 2016

Water temperature affects physical and biological processes in ecologies on river system and is important conditions for growth rate and spawning of fish species. The objective of this study is to compare models for water temperature during the summer season for the Fourchue River (St-Alexandre-de-Kamouraska, Quebec, Canada). For this, three different models, which are CEQUEAU, Auto-regressive Moving Average with eXogenous input and Nonlinear Autoregressive with eXogenous input, were applied and compared. Also, future water temperature in the Fourchue river were simulated and analyzed its result based on the CMIP5 climate models, RCP 2.6, 4.5, 8.5 climate change scenarios. As the result of the study, the water temperature in the Fourchue river are actually changed and median water temperature will increase $0.2{\sim}0.7^{\circ}C$ in June and could decrease by $0.2{\sim}1.1^{\circ}C$ in September. Also, the UILT ($24.9^{\circ}C$) for brook trout are also likely to occurred for several days.

• Journal of Wetlands Research
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• v.19 no.3
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• pp.359-365
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• 2017

Impermeable surfaces such as transportation land uses including roads and parking lots accumulate high heavy metals and particulate matters concentration especially during dry season which worsens the river water quality and distort the water circulation system during rainfall events. Recently, the government has been promoting policies to install Low Impact Development (LID) facilities such as permeable pavements or grass blocks in parking lots or pavements. However, transition of asphalt-paved surfaces to permeable pavement generated asphalt wastes which are detrimental to the environment and has cost implications due to its removal and disposal. Therefore this study was conducted to provide a method of constructing a cost-effective permeable pavement to reduce waste generation and cost. In this study, comparative analysis of the water circulation capacity and economic efficiency of the traditional construction method and new method proposed in this study through the lab-scale experiment. The proposed method was to make holes in existing asphalt pavements, layout geotextile fabric and permeable base media such as sand before compaction. After compaction, layout grass blocks on the compacted base media then layout sand in between each grass blocks before compaction. Apparently, there was no significant difference between the traditional installation method of permeable pavement and the proposed method in this study considering surface runoff, infiltrated volume, stored volume, and rainfall-runoff delay time. The proposed method in this study generated 86% less wastes compared to the traditional installation method and has 70% cost reduction considering asphalt removal and disposal. The construction method proposed in this study yielded similar performance compared to the traditional installation method and water circulation effect, but was proven to be less complicated and economical.

• Korean Journal of Ecology and Environment
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• v.50 no.3
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• pp.337-354
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• 2017

Cyanobacteria Aphanizomenon population is widely distributed in the world, and well known as harmful algae by producing toxins and off-flavor materials, thus belonging to one of the taxa that became more interested in the field of limnoecology. In this study, the frequency, intensity, and duration of Aphanizomenon occurrence were increased with the abnormal drawdown of water level in the winter in Boryeong Reservoir, and the spatial and temporal characteristics of them are compared with each other in the perspective of hydrometeorology (1998 to 2017) and limnology (2010 to 2017). In Korea, Aphanizomenon flourished mainly in high temperature, and the appearance in the low temperature was rare in total five times. The harmful cyanobacteria Aphanizomenon was observed in the low temperature (December to February) in Boryeong Reservoir from 2014, and then reached a maximum value of $2,160cells\;mL^{-1}$ in January 2017. In addition, the period exceeding $1,000cells\;mL^{-1}$ at this time was more than 3 months. This was simultaneously associated with abnormal water level fluctuation in the low temperature ($<10^{\circ}C$). The large drawdown of water level in the winter season has the potential to promote or amplify the germination and development of harmful algae. Also, subsequent water quality and ecological impacts(e.g., algal toxins and off-flavor substances) need to be considered carefully.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.5
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• pp.129-136
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• 2012

Temperature of fresh concrete can be effectively used to predict the strength of concrete being cured and make an informed decision for stripping the molds. A hygrothermograph and thermo-couple sensors that require an extensive wiring have been applied to measure a temperature of concrete at the early stage of the curing process on site. However, these methods have limits to provide the temperature data in real time due to harsh working environment including frequent cutting of wires. Therefore, this study is aiming at developing a device based on wireless sensor network to measure the temperature of concrete being cured in formwork. The result showed that the wireless sensor with probe type thermistor which is developed had the same temperature data compared to the existed wire type thermistor, and we confirmed the temperature history of concrete in real time for 28 days throughout the gateway by wireless network that collects the temperature data measured from specimens in laboratory. Also, the network device for transmission can be easily separated from the probe sensor part and reused consistently. If the wireless sensor network device developed uses in the field, the temperature management of concrete will be systematically conducted from at the early stage of the curing, and especially be effective for cold weather concrete construction. In addition, it will contribute to the establishment of advanced quality control system for concrete and productivity of supervisors on site will be increased in the future.

• Journal of the Society of Disaster Information
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• v.11 no.2
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• pp.203-209
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• 2015

The heat detector detects heat in the fire and is an important core element of the automatic fire alarm system used generally for every fire prevention objects. The heat detector is distinguished in spot type and spread type and in spot type, there are differential and thermistor types. These heat detectors give a great influence on the loss of people and property according to the sensitivity of response such as operation time and operation temperature in actual fire and in overseas people apply it for the development of products that can be operated in the early stage of fire including certification, quality management, and comparison standard by introducing response time index through the theory of heat balance that considers the heat loss and ventilation tests. In Korea, the response time index is introduced and used in the head of sprinkler products, but it is not applied to the heat detector at present. It is necessary to introduce the response time index that shows the sensitivity of response of the heat detector the installation standard for the heat detector that the response time index is applied should be different according to the fire weight, danger degree of fire, and shape of buildings. Through this study, it tries to help reduce lives and property of people through the swift warning by installing detectors suitable for the building structure.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.204-210
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• 2006

The purple color in flesh of 'Jasim' potato (Solanum tuberosum L.) tubers is due to an accumulation of anthocyanin. The experiment was conducted to determine what is the key factor among cultural environments that affect the accumulation of anthocyanin in 'Jasim' potato tubers, and the effect of nitrogen fertilization levels on that. Through analysis of anthocyanin content of purple-fleshed tubers produced under the different cultural environments of three localities and two planting dates, we determined that lower temperature during 30days before harvesting resulted in higher anthocyanin accumulation of 'Jasim' potato tubers. In the experiment of different level of nitrogen fertilization, 'Jasim' potato tubers produced in highland (Daegualryeong) showed higher content of anthocyanin in the treatment of recommended level than in treatment of lower or higher level as compared with the recommended level. However, significant difference of anthocyanin content among different nitrogen fertilization levels was not observed in lowland (Gangnung). These results suggest that the selection of locality or cropping system and the optimal fertilization management are very important factors for production of higher pigmented tubers in purple-fleshed potato.