• Journal of information and communication convergence engineering
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• v.20 no.2
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• pp.125-130
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• 2022

In modern society, as many data are used for research or commercial purposes, the value of data is gradually increasing. In related fields, research is being actively conducted to collect valuable data, but it is difficult to collect proper data because the value of collection is determined according to the performance of existing sensors. To solve this problem, a method to effectively reduce noise has been proposed, but there is a point in which performance is degraded due to damage caused by noise. In this paper, a device capable of collecting time series data was designed to correct such data noise, and a correction technique was performed by giving an error value based on the representatively collected ultrafine dust data, and then comparing before and after Compare performance. For the correction method, Kalman, LPF, Savitzky-Golay, and Moving Average filter were used. Savitzky-Golay filter and Moving Average Filter showed excellent correction rate as an experiment. Through this, the performance of the sensor can be supplemented and it is expected that data can be effectively collected.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.4
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• pp.29-41
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• 1994

The purposes of this study are (a)to investigate the effect of follow-up on the increase of response rate;(b)to analyze the effect of follow-up on the statistics by predetermined response rates ; therefore, (c)to describe the importance of high response rate and to suggest methods in order to increase response rate in mail survey. Telephone directory of Seoul was utilized as a sampling frame, and modified Total Design Method(TDM) was applied to collect the data. The results are summarized as follows. 1. Final response rate was 76.5% by 2 follow-ups. 2. The first follow-up with telephone call had a significant effect on increase of response rate. As a result, follow-up by postcard in TDM could be omitted in this method. 3. The second follow-up by registered mail did not have a significant effect. Therefore, use of this procedure is depending upon such research situtations as importance of high response rate and cost available. 4. Follow-ups helped to make collected sample highly representative. 5. Most questionnaires were arrived on the first half of data collection period in each follow-up. 6. Most of questionnaires were collected for 10 weeks. Accumulated responses could be fitted by exponential and logistic curve, simultaneously. The fitted curve suggested that eventually limited number of questionnaires by arrived. So, if researchers want higher response rate, they have to conduct more follow-ups. 7. Statistics in the predetermined response rate were not changed significantly. But replications are needed to generalize this result.

• Journal of Multimedia Information System
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• v.7 no.2
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• pp.125-136
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• 2020

Nowadays, cloud computing is becoming more popular among companies. However, the characteristics of cloud computing such as a virtualized environment, constantly changing, possible to modify easily and multi-tenancy with a distributed nature, it is difficult to perform attack detection with traditional tools. This work proposes a solution which aims to collect traffic packets data by using Flume and filter them with Spark Streaming so it is possible to only consider suspicious data related to HTTP Slow Rate Denial-of-Service attacks and reduce the data that will be stored in Hadoop Distributed File System for analysis with the FP-Growth algorithm. With the proposed system, we also aim to address the difficulties in attack detection in cloud environment, facilitating the data collection, reducing detection time and enabling an almost real-time attack detection.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.737-741
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• 2007

This paper analyses the environmental effect of 100kw PV system installed in Tibet using Life Cycle Assessment(LCA). Then, energy payback time(EPT) and life-cycle $CO_2$ emission rate are estimated based on life-cycle of the PV system. As a result of the estimation, 6 year of EPT and 20 g-C/kWh of $CO_2$ emission rate are obtained. In China, average $CO_2$ emission rate of fossil fuel power generation plant is 260 g-C/kWh. This shows that PV system would be very promising for global environmental issues. For advanced LCA, we need to collect detailed and various data about raw material of PV system.

• Journal of Korean Society for Quality Management
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• v.34 no.2
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• pp.1-11
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• 2006

This paper is related to the effect analysis of certification of ISO 9000 Quality Management System. We collect and analyze the field data of certification costs and profit from companies that are located at southeast area in Korea. The effect analysis is based on the type and scale of companies. We use defective rate and inventory turnover rate as the criterion of positive effect after certification. As a result, we may conclude that the certification of ISO Quality Management System gives companies positive effects.

• New & Renewable Energy
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• v.3 no.2 s.10
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• pp.11-16
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• 2007

This paper analyses the environmental effect of 100kw PV system installed in Tibet using Life Cycle Assessment(LCA). Then, energy payback time(EPT) and life-cycle CO2 emission rate are estimated based on life-cycle of the PV system. As a result of the estimation, 6 year of EPT and 20 g-C/kWh of CO2 emission rate are obtained. In China, average CO2 emission rate of fossil fuel power generation plant is 260 g-C/kWh. This shows that PV system would be very promising for global environmental issues. For advanced LCA, we need to collect detailed and various data about raw material of PV system.

• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.49-54
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• 1996

The anaerobic landfill leachate treatment can surmount dilution problem of high concentration landfill leachate, collect methane gas as byproduct, and treat low phosphate concentration leachate because of low nutrient salt requirement. The problems of conventional anaerobic treatment that are requirement of large reactor because of low microbial growth rate(HRT=20-30 days) and low volumetric loading rate(VLR=0.5-2.0 kg $COD/m^3\cdot day$) are able to surmount by introduction of high rate anaerobic treatment. In this study, the upflow blanket filter(UBF) which is high rate anaerobic process was applyed to the landfill leachate treatment. The acceptable volumetric loading rate and HRT were 18.23 kg $SCOD/m^3\cdot day$ and 13 hrs. SCOD removal rate was over 90% at VLR 18.23 kg $SCOD/m^3\cdot day$. The methane gas yield was $0.15 lCH_4/g$ SCOD added(at STP) at VLR 18.23 kg $SCOD/m^3\cdot day$. The solids accumulation yield was 0.40 g VSS/g COD removed.

• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.169-177
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• 2015

We develop a model to predict typhoons in Korea. We collect data for typhoons and classify those depending on the severity level. Following a Bayesian approach, we develop a model that explains the relationship between different levels of typhoons. Through the analysis of the model, we can predict the rate of typhoons, the probability of approaching Korean peninsular, and the probability of striking Korean peninsular. We show that the uncertainty for the occurrence of various types of typhoons reduces dramatically by adaptively updating model parameters as we acquire data.

• Korean Linguistics
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• v.39
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• pp.223-257
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• 2008

The purpose of this paper is to get characteristics about Korean negative sentences in the 17th century. In this paper used method is to classify and collect statistics of negative sentences in the 17th century Korean literatures, then to reclassify according to morphological characteristics of predicates. The subjects of analysis are 'ani'(don't)' and 'mos(can't)' negative sentences except for 'malta(forbid)' negative sentences.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.113-121
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• 2020

With the rapid development of information and communication technology (ICT), various sensors are being embedded in wearable devices. Consequently, these devices can continuously collect data including health data from individuals. The collected health data can be used not only for healthcare services but also for analyzing an individual's lifestyle by combining with other external data. This helps in making an individual's life more convenient and healthier. However, collecting health data may lead to privacy issues since the data is personal, and can reveal sensitive insights about the individual. Thus, in this paper, we present a method to collect an individual's health data from a smart band in a privacy-preserving manner. We leverage the local differential privacy to achieve our goal. Additionally, we propose a way to find feature points from health data. This allows for an effective trade-off between the degree of privacy and accuracy. We carry out experiments to demonstrate the effectiveness of our proposed approach and the results show that, with the proposed method, the error rate can be reduced upto 77%.