• Title/Summary/Keyword: frequency-based method

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A study on vulnerability analysis and incident response methodology based on the penetration test of the power plant's main control systems (발전소 주제어시스템 모의해킹을 통한 취약점 분석 및 침해사고 대응기법 연구)

  • Ko, Ho-Jun;Kim, Huy-Kang
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.24 no.2
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    • pp.295-310
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    • 2014
  • DCS (Distributed Control System), the main control system of power plants, is an automated system for enhancing operational efficiency by monitoring, tuning and real-time operation. DCS is becoming more intelligent and open systems as Information technology are evolving. In addition, there are a large amount of investment to enable proactive facility management, maintenance and risk management through the predictive diagnostics. However, new upcoming weaponized malware, such as Stuxnet designed for disrupting industrial control system(ICS), become new threat to the main control system of the power plant. Even though these systems are not connected with any other outside network. The main control systems used in the power plant usually have been used for more than 10 years. Also, this system requires the extremely high availability (rapid recovery and low failure frequency). Therefore, installing updates including security patches is not easy. Even more, in some cases, installing security updates can break the warranty by the vendor's policy. If DCS is exposed a potential vulnerability, serious concerns are to be expected. In this paper, we conduct the penetration test by using NESSUS, a general-purpose vulnerability scanner under the simulated environment configured with the Ovation version 1.5. From this result, we suggest a log analysis method to detect the security infringement and react the incident effectively.

Relationship between Service Quality and Behavior by Spectators Participating Security Exhibition (보안엑스포 참관객의 인지된 서비스 품질과 참관 후 행동의 관계)

  • Jang, Jong-Oh;Kim, In-Jae
    • Korean Security Journal
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    • no.45
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    • pp.65-86
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    • 2015
  • The purpose of this study was aimed to identify the relationship between service quality and behavior by spectators participating security exhibition. The subject for this study was spectators who participating World Security Expo 2014 held three days from March 12 to 14 in 2014. 350 samples were selected by convenience sampling for subject of this study. 320 out of 350 surveys, excluded 30 unfaithful and defected surveys, were used for data analysis. Research tool was questionnaire which was based on and recomposed by previous researches home and abroad. The collected data were treated for analysis of frequency, reliability, factor analysis, correlation, and multitiple regression analysis by using SPSS statistic package version of 18.0 Through the above research method and procedure, the results were as followings. First, the relationship between service quality and behavior after participating exhibition appeared positively. It was found that there was high relationship between service quality and behavior. Second, analyzing relationship of factors between service quality and behaviors resulted to effect perceived environment, human services, and product on word of mouth. Third, analyzing relationship of factors between service quality and behaviors resulted to effect perceived environment, product, and price on re-participation.

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Kinematic Characteristics Based on Proficiency In Geoduepyeopchagi in Taekwondo Poomsae Koryo

  • So, Jae Moo;Kang, Sung-Sun;Hong, AhReum;Jung, Jong Min;Kim, Jai Jeong
    • Korean Journal of Applied Biomechanics
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    • v.26 no.4
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    • pp.343-351
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    • 2016
  • Objective: The purpose of this study was to help improve game performance and provide preliminary data to enhance the efficiency of the kick and stability of the support foot by comparing the kinematic characteristics of the repeated side kick (geodeupyeopchagi) in poomsaeKoryo between expert and non-expert groups. Method: The subjects were divided into 2 groups according to proficiency in Taekwondo, an expert group and a non-expert group (n = 7 in each group), to observe the repeated side-kick technique. Four video cameras were set at a speed of 60 frames/sec and exposure time of 1/500 sec to measure the kinematic factors of the 2 groups. The Kwon3D XPprogramas used to collect and analyze three-dimensional spatial coordinates. Ground reaction force data were obtained through a force plate with a 1.200-Hz frequency. An independent samplesttest was performed, and statistical significance was defined as .05. The SPSS 18.0 software was used to calculate the mean and standard deviation of the kinematic factors and to identify the difference between the experts and non-experts. Results: The angular displacement of the hip joint in both the expert and non-expert groups showed statistical significance on E1 and E4 of the left support foot and E5 of the right foot (p<.05). The angle displacement of the knee joint in both groups showed statistical significance on E4 of the left support foot, and E1 and E2 of the right foot (p<.05). The angular velocity of the lower leg in both groups showed no statistical significance on the left support foot but showed statistical significance on E2 and E6 of the right foot (p<.05). The angular velocity of the foot in both groups showed no statistical significance on the left support foot but showed statistical significance on E2 of the right foot (p<.05). The vertical ground reaction force in both groups showed statistical significance on E2 (p<.05). The center of pressure in all directions in both groups showed statistical significance (p<.5). Conclusion: While performing the repeated side kick (geodeupyeopchagi), the experts maintainedconsistency and stability of the angle of the support leg while the kick foot moved high and fast. On the other hand, the angle of the support foot of non-experts appeared inconsistent, and the kick foot was raised, relying on the support leg, resulting in unstable and inaccurate movement.

Variation of design flood according to the temporal resolution and periods of rainfall (강우의 시간해상도와 자료기간에 따른 설계홍수량의 변동성)

  • Kim, Min-Seok;Lee, Jung-Hwan;Moon, Young-Il
    • Journal of Korea Water Resources Association
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    • v.51 no.7
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    • pp.599-606
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    • 2018
  • Most hydrological analysis such as probability rainfall and rainfall time distributions have typically carried out based on hourly rainfall and rainfall - runoff analysis have carried out by applying different periods of rainfall time distribution and probability rainfall. In this study, to quantify the change of design flood due to the data type (hourly and minutely rainfall data) and the probability rainfall and application of different data period to the rainfall time distribution, probability rainfall is calculated by point frequency analysis according to data type and period and rainfall time distribution was calculated by Huff's quartile distributions. In addition, the change analysis of design flood was carried out by rainfall - runoff analysis applying different data periods of design rainfall time distribution. and probability rainfall. As a result, rainfall analysis using minute rainfall data was more accurate and effective than using hourly rainfall data. And the design flood calculated by applying different data period of rainfall time distribution and probability rainfall made a large difference than by applying different data type. It is expected that this will contribute to the hydrological analysis using minutely rainfall.

The Change of Korean Men's Pants Design from 1962 to 1998 - Based on the Content Analysis of Magazine Advertisements and Pictorials -

  • Kwon, Hae-Sook
    • Journal of Fashion Business
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    • v.10 no.6
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    • pp.52-62
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    • 2006
  • The purpose of this study is to investigate the changes of modern Korean men's pants design from 1962 to 1998 by reviewing fashion magazine advertisements and pictorials. For theoretical study, the characteristics and the importance of apparel advertisements and the changes of modern Korean men's fashion trend were reviewed. For sample selection, first, 932 pictorials of men';s wear designs from Joongang Magazine, Shin Dong-A, Bokjangwolbo, Meot, Men's Life, WWD, and SFAA's photograph album, published from 1962 to 1998 were selected and then excluded some samples that could not clearly identify the pants design. Content analysis method was used to analyze the content of magazines and pictorials. The final samples are classified into pattern, color, length, silhouette, and existence or non-existence of turn-up. Frequency and $x^2$-test were conducted using a SAS statistics package to analyse the data. The results were as follows. ; (1) Solid pattern was the most prevailed throughout the last four decades and followed by stripe, check, the others, abstract, dot and floral. There is no significant difference in the type of men's pants pattern between each decade. (2) It showed a significant difference in colors of men's pants between decades. The colors in men's wear are divided into nine categories and the order of occurrence are as follows; multi-color is the most frequently shown and followed by brown, gray, blue, black, green, pink, yellow, and red. More various colors appeared over the period, however, multi color was the most popular in all decades but in the 60s. (3) Full length of pants style occupied more than 96% throughout all four decades. Due to the popularity of sports wear in men's fashion during the 90s, the shorts style appeared not only in sports wear and casual wear but also in suit style. (4) There is a significant difference in silhouette of men's pants between decades. The silhouette of men's pants were divided into four types and their order of occurrence are as follows; basic, baggy, fitted, and loose silhouette. Basic silhouette was the most prevailed throughout the whole four decades. (5) A significant difference was shown in the existence or non-existence of turn-up of men's pants between decades. Non-existence of turn-up of men's pants was the most prevailed throughout the whole four decades.

The effect of flower decoration on customer's satisfaction and re-visit of a baby's first birthday (화훼장식이 돌잔치 고객의 만족도와 재방문 의도에 미치는 영향)

  • Kim, Joung Hee;Lim, Young Hee;Kim, Kiu Weon
    • FLOWER RESEARCH JOURNAL
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    • v.19 no.1
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    • pp.68-76
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    • 2011
  • This study was conducted to investigate customer taste related to satisfaction of a baby's first birthday party and re-visit of venues. General characteristics of customers were similar in male and female or the married and the unmarried. Mainstream age of respondents was from in their 20's to 30's. Among them, the number of university graduates were the largest in education level. Theoretical model was composed with seven significant variables of design style and composition and design harmony and color sense for flower decoration, accessibility, facility, service and price, satisfaction, and intention of re-visit based on the result of analysis on these factors. Exploratory factor analysis was performed using SPSS 14.0K. Structural equation modeling(SEM) for simultaneous measure of path coefficient in all casualty of study model, measurement model of AMOS 7.0 for evaluation of validity, and reliability and factor analysis method using technical statistics, frequency analysis, and Cronbach's Alpha for data analysis were used. The result of hypothesis verification showed that design style and composition was the most significant item in satisfaction of parameter and it was followed by design harmony and color sense. While service and price had positive effect on satisfaction, accessibility and facility had no relation to it. It means that the most crucial variable was a flower decoration in planning and representation of the celebration of baby's first birthday. In conclusion, the finding of this study suggests that the effective utilization of these variables will contribute to the enhancement of satisfaction affecting improvement service and price or intention of re-visit.

A Geomorphological Study on the Locational Characteristics and Construction Method of Dolmens in Hyosanri·Daesinri (지석묘의 입지특성과 축조방식에 대한 지형학적 고찰 - 효산리·대신리를 중심으로 -)

  • PARK, Cheol-Woong;KIM, In-Cheol
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.3
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    • pp.23-36
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    • 2012
  • This study aims to think about the problem of dolmens: the reasons for the presence of dolmens and how to construct it, at the point of view of geographical and geomorphological. The subjects of this study is the dolmens which locate between at Dogok Hyosanri and Chunyang Daesinri Hwasoon-gun, Jeonlanamdo. The study areas in Hyosanri, Daesinri has been observed as follows. First, the long axis direction of Dolmen upper stone and the slope one are the same. Second, tor, block stream, hockey stick, etc. Third, Composition of the soil silt> sand> clay is distributed in the order. Forth, The soil of high quality silt and the roundness of angular, sub-angular-level and the high frequency, peaks of quarts and illite clay minerals show. Fifth, in the result of $SiO_2/Al_2O_3$, $SiO_2/R_2O_3$, and CIA(Chemical Index of Alteration), Hyosanri, Daesinri areas show mechanical weathering was dominant and chemical weathering environment was not being progressed. The blocks used in construction of dolmens had moved to the bottom of slopes by mass movement such as solifluction then them which had been placed in the position seem to be used by people of Bronze. Based on the above results, the process of construction of dolmens can be estimated as follows. They would dig up the ground under the upper stone of dolmens, put the supporting stone in the place, then dig up earth, place into remains, close the obturating stones, then heal up earth.

Study on Factors for Passenger Risk in Railway Vehicle (철도차량내 승객 위험요소 선정 연구)

  • Park, Won-Hee;Park, Sung-Joon;Kim, Hyo-Jin;Kim, HanSaem;Oh, Sechan
    • Journal of the Society of Disaster Information
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    • v.17 no.4
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    • pp.733-746
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    • 2021
  • Purpose: This study was conducted for the purpose of selecting important events from among various events that may pose a risk to railway passengers. For this purpose, opinions of various railroad vehicle passengers and railway operator workers were investigated and analyzed. Method: The survey was conducted on 1,000 men and women in their 20s and 60s and 429 workers at 11 company across the country. A survey was conducted on the dangerous situations that may occur in subways, general railroads and high-speed rail vehicles targeting passengers. For railway operator workers, the questionnaire is limited to subway vehicles. Result: Among the passenger risk factors(abnormal behavior and dangerous situations) selected based on the frequency and importance of occurrence of passenger risk factors, the main risk factors are selected 'car door jamming', 'sexual harassment', 'intoxicating behavior', 'fighting' /assault', 'wandering around', and 'not wearing a mask'. Conclusion: The major risk factors affecting passengers were selected by surveying passengers and railway operators. we plan to develop a CCTV detection system with AI technology that can quickly and continuously detect the major risk factors of railway vehicles selected as a result of this study.

Convergence of Acupoint and Electrical Stimulation Therapy for Blood Flow and Pain Threshold (혈류량과 통증역치에 대한 경혈과 전기자극치료의 융합연구)

  • Yi, Dong-Hyun;Kim, Beom-Ryong;Hur, Yoon-Jung;Kim, Dong-Hoon;Shim, Su-Young;Yim, Jong-Eun
    • Journal of the Korea Convergence Society
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    • v.10 no.6
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    • pp.79-87
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    • 2019
  • This study examined how the application of silver spike point (SSP) and acupuncture-like transcutaneous electrical nerve stimulation (A-TENS) on acupoints affects blood flow and pain threshold, using laser Doppler blood fluxes and the Commander algometer. Our study included 32 healthy men and women who were randomly divided into the SSP group (n=18) and the A-TENS group (n=14). The pain threshold and blood flow were measured at the Neiguan (PC6) of the Jueyin Pericardium Meridian of the hand. SSP was performed with a 2.8cm electrode at a fixed frequency of 3 Hz for 15 minutes. The change in blood flow and pain threshold after the intervention significantly differed between the two groups (p<0.05). We found that the application of SSP and A-TENS on an acupoint altered their blood flow and pressure pain threshold, with SSP resulting in significantly greater change than A-TENS. Based on these results, the convergence of acupoint and electrical stimulation therapy can be usefully applied as a method for various patients. Continued development of convergence interventions is necessary.

Geoacoustic Model at the YSDP-105 Long-core Site in the Mid-eastern Yellow Sea (황해 중동부 해역 YSDP-105 심부코어 지점의 지음향 모델)

  • Ryang, Woo-Hun;Jin, Jae-Hwa;Hahn, Jooyoung
    • Journal of the Korean earth science society
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    • v.40 no.1
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    • pp.24-36
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    • 2019
  • In the mid-eastern Yellow Sea, glacio-eustatic sea-level fluctuations and a regional tectonic subsidence have combined to represent an aggradational stacking pattern of sedimentary units during late Pleistocene-Holocene. The accumulated sediments are divisible into two-type units of Type-A and Type-B in high-resolution air-gun seismic profiles and the deep-drilled core of YSDP-105. Type-A unit largely comprises clast-rich coarse-grained sediments of non-marine to paralic origin, whereas Type-B unit consists mostly of tidal fine-grained sediments. Based on a bottom model of the sedimentary units, this study suggested a geoacoustic model of long-coring bottom layers at the YSDP-105 drilling site of the mid-eastern Yellow Sea. The geoacoustic model of 64-m depth below the seafloor with four-layer geoacoustic units was reconstructed in continental shelf strata at 45 m in water depth. For actual modeling, the geoacoustic property values of the models were compensated to in situ depth values below the seafloor using the Hamilton modeling method. We suggest that the geoacoustic model will be used for geoacoustic and underwater acoustic experiments of mid- and low-frequency reflecting on the deep bottom layers in the mid-eastern Yellow Sea.