• Title/Summary/Keyword: Safety measure time

검색결과 430건 처리시간 0.023초

A Study on Electrode Array for Measurement of Induced Polarization of Rock Samples (암석 시료의 유도분극 측정을 위한 전극배열 비교)

  • Man-ho Han;Jung-hwan Lee;Keun-Soo Lee;Myeong-Jong Yi
    • Tunnel and Underground Space
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    • 제33권6호
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    • pp.483-494
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    • 2023
  • Measurement of the physical properties of rocks or minerals is an important factor in determining the distribution of the underground medium as well as mineral resource investigations. Resistivity and induced polarization, which are widely used in Korea, are methods for measuring electrical properties, which are representative properties of obtaining subsurface information. In order to precisely analyze the exploration data obtained from various sites, it is important to accurately measure the material properties. Electrical properties of rock is measured using two-electrode or four-electrode method. Compared to the four-electrode method, the two-electrode method is generally used because it is very easy to contact the sample and the electrode, but there is a problem in that the impedance of the electrode and the sample is measured together. In this study, the time-domain the induced polarization effects were measured using the 2-electrode method and the 4-electrode method for artificial samples mixed with graphite and cement having induced polarization characteristics, and the results were compared. Although the 4-electrode method has difficulties in installing potential electrodes, it was confirmed that it is effective in measuring electrical properties because it can reduce the problem caused by the impedance of potential electrodes compared to the 2-electrode method.

Leakage noise detection using a multi-channel sensor module based on acoustic intensity (음향 인텐시티 기반 다채널 센서 모듈을 이용한 배관 누설 소음 탐지)

  • Hyeonbin Ryoo;Jung-Han Woo;Yun-Ho Seo;Sang-Ryul Kim
    • The Journal of the Acoustical Society of Korea
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    • 제43권4호
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    • pp.414-421
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    • 2024
  • In this paper, we design and verify a system that can detect piping leakage noise in an environment with significant reverberation and reflection using a multi-channel acoustic sensor module as a technology to prevent major plant accidents caused by leakage. Four-channel microphones arranged in a tetrahedron are designed as a single sensor module to measure three-dimensional sound intensity vectors. In an environment with large effects of reverberation and reflection, the measurement error of each sensor module increases on average, so after placing multiple sensor modules in the field, measurement results showing locations with large errors due to effects such as reflection are excluded. Using the intersection between three-dimensional vectors obtained from several pairs of sensor modules, the coordinates where the sound source is located are estimated, and outliers (e.g., positions estimated to be outside the site, positions estimated to be far from the average position) are detected and excluded among the points. For achieving aforementioned goal, an excluding algorithm by deciding the outliers among the estimated positions was proposed. By visualizing the estimated location coordinates of the leakage sound on the site drawing within 1 second, we construct and verify a system that can detect the location of the leakage sound in real time and enable immediate response. This study is expected to contribute to improving accident response capabilities and ensuring safety in large plants.

An Open-label, Randomized, Comparative Assessment of the Efficacy and Safety between Tofisopam and Lorazepam in Anxiety Disorder (Tofisopam과 lorazepam의 항불안효과와 안전성에 대한 비교 연구)

  • Lee, Min Soo;Kim, Yong-Ku;Kwak, Dong-Il
    • Korean Journal of Biological Psychiatry
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    • 제4권2호
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    • pp.265-271
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    • 1997
  • Objective : A 4-week, single-blind, parallel group study was conducted to evaluate the efficacy and safety of tofisopam and lorazepam in 32 outpatients with anxiety disorder. Methods : Patients were randomized to receive either tofisopam(N=17) or lorazepam(N=15). The starting dose of tofisopam was 50mg t.i.d. daily, which could be increased to a maximum of 100mg t.i.d. according to the patient's clinical response and side effect. The starting dose of lorazepam was 0.75mg b.i.d. daily, which could be increased to a maximum of 1.5mg b.i.d. depending on the patient's clinical response and side effect. Efficacy evaluations at baseline, week 1, 2, and 4 used the 14-item Hamilton Rating Scale for Anxiety(HAM-A) and Clinical Global Impression(CGI). Tolerability was assessed by response to a nonleading question concerning adverse events. Laboratory parameters including vital sign, EKG, hematological, and biochemical values were measured during trial. Results : No significant differences between HAM-A total scores, two HAM-A factors(psychic, somatic) and CGI severity scores were recorded at any point during tofisopam and lorazepam treatments. However, in each group there was a significant decrease in HAM-A total scores, two HAM-A factor s(psychic, somatic), CGI severity scores over time. The pecentages of patients with tofisopam who at least minimally improved increased from 64.7% at week 1 to 94.1% at week 4. The pecentages of patients with lorazepam who at least minimally improved increased from 40.0% at week 1 to 66.7% at week 4. The pecentages of patients with tofisopam who had not any adverse event increased from 58.8% at week 1 to 87.9% at week 4. The pecentages of patients with lorazepam who had not any adverse event were not changed from 46.7% at week 1 to 46.7% at week 4. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial in both groups. Conclusion : These data suggest that tofisopam may be effective in reducing anxiety and is a anti-anxiety drug of identical potency with lorazepam. Tolerability of tofisopam was superior to lorazepam. These findings should be confirmed by using double-blind crossover study with a large member of patients.

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National Management Measures for Reducing Air Pollutant Emissions from Vessels Focusing on KCG Services (선박 대기오염물질 배출 현황 및 저감을 위한 국가 관리 대책 연구: 해양경찰 업무를 중심으로)

  • Lee, Seung-Hwan;Kang, Byoung-Yong;Jeong, Bong-Hun;Gu, Ja-Yeong
    • Journal of the Korean Society of Marine Environment & Safety
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    • 제26권2호
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    • pp.163-174
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    • 2020
  • Particulate matter levels are rapidly increasing daily, and this can affect human health. Therefore, air pollutant emissions from sea vessels require management. This study evaluates the status of air pollutants, focusing on air pollutant emissions from the vessels of the Korea Coast Guard (KCG), and proposes national management measures to reduce emissions. According to a report recently released (2018) by the National Institute of Environmental Research (NIER), emissions from vessels constituted 6.4 % of the total domestic emissions, including 13.1 % NOx, 10.9 % SOx, and 9.6 % particulate matter (PM10/PM2.5). Among the rates of pollutant emission from vessels, the emission rates of domestic and overseas cargo vessels were the highest (50.6 %); the ratio of fishing boats was 42.6 %. With respect to jurisdictional sea area, 44.1 % of the emissions are from the south sea, including the Busan and Ulsan ports, and 24.8 % of the emissions are from the west sea, including the Gwangyang and Yeosu ports. The KCG inspects boarding lines to manage emission conditions and regulate air pollutant emissions, but it takes time and effort to operate various discharge devices and measure fuel oil standards. In addition, owing to busy ship schedules, inspection documents are limited in terms of management. Therefore, to reduce the air pollutant emissions of such vessels, regulations will be strengthened to check for air pollutants, and a monitoring system based on actual field data using KCG patrol ships will be established, for each sea area, to manage the emissions of such vessels. Furthermore, there is a need for technological development and institutional support for the introduction of environmentally friendly vessels.

The Problems and Improvement Measures of Protection for Politician (정치인 경호제도의 문제점 및 개선방안)

  • Jo, Sung-Gu;Kim, Tae-Min
    • Korean Security Journal
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    • 제22호
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    • pp.169-196
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    • 2010
  • Although more priority is given to politicians from the aspect that they represent people and decide the future of country, the current situation is that politicians are not free from terrorism because of insufficient guard-concerned law, negative social recognition and increased crime and terrorism. The measure for politician terrorism shall be handled from the aspect of national security rather than public peace. For the purpose, basic legal foundation shall be prepared and specialized guard technique considering specialty of politician shall be established. Basic solution shall be established by reinforcing law against politician terrorism and establishing new law from the national viewpoint. The guard for politician has two faces that both of safety of guard target and voting intention of voter shall be met at the same time. Although special guard technique is required for guarding politician, current situation is that it is not researched professionally. In relation to the measure to develop the system of protection for politician, First, the study suggested legal foundation for politician guard. Although the 17th National Assembly proposed revised legal plan to protect politician from terrorism, it is suspended, expired and abolished now. The legal plan presented by members of the National Assembly was simply restricted to the scope of public guard. The study divided establishment of legal foundation into two things. The first one is the dispatch type of effective public guard and the second one is the transfer to private guard. Second, the study suggested environmental development method of politician guard. in the environment of politician guard, the study suggested improvement and development method by analyzing social recognition, politician's mind and voter's mind psychologically. After the beginning of human society, if human race is continued, political activity won't disappear. It is obvious that the safety of political leader is very important issue for human race because he plays the role to decide the future of human. In the future, more specialized, effective law shall be prepared and deeper study of scholar shall be performed.

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Clinical assessment of whitening efficacy and safety of in-office tooth whitening system containing 15% hydrogen peroxide with or without light activation (15% 과산화수소 함유 전문가용 치아 미백제의 광활성화 여부에 따른 미백효과 및 안전성에 관한 임상평가)

  • Noh, Young-Suk;Rho, Young-Jee;Yoo, Yeon-Jee;Lee, Hyang-Ok;Lim, Sang-Min;Kweon, Hyun-Jeong;Kim, Ye-Un;Park, Seong-Yeon;Yoon, Hee-Young;Lee, Jung-Hyun;Lee, Chan-Hee;Oh, So-Ram;Kum, Kee-Yeon
    • Restorative Dentistry and Endodontics
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    • 제36권4호
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    • pp.306-312
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    • 2011
  • Objectives: This clinical study evaluated the effect of light activation on the whitening efficacy and safety of in-office bleaching system containing 15% hydrogen peroxide gel. Materials and Methods: Thirty-three volunteers were randomly treated with (n = 17, experimental group) or without light activation (n = 16, control group), using Zoom2 white gel (15% $H_2O_2$, Discus Dental) for a total treatment time of 45 min. Visual and instrumental color measurements were obtained using Vitapan Classical shade guide and Shadepilot (DeguDent) at screening test, after bleaching, and 1 month and 3 month after bleaching. Data were analyzed using t-test, repeated measure ANOVA, and chi-squared test. Results: Zoom2 white gel produced significant shade changes in both experimental and control group when pre-treatment shade was compared with that after bleaching. However, shade difference between two groups was not statistically significant (p > 0.05). Tooth shade relapse was not detected at 3 months after bleaching. The incidence of transient tooth sensitivity was 39.4%, with being no differences between two groups. Conclusions: The application of light activation with Zoom2 white gel system neither achieved additional whitening effects nor showed more detrimental influences.

Soil-to-Plant Transfer of $^{54}Mn,\;^{60}Co,\;^{85}Sr$ and $^{137}Cs$ Deposited during the Growing Season of Potato (감자의 재배기간 중 토양에 침적한 $^{54}Mn,\;^{60}Co,\;^{85}Sr,\;^{137}Cs$의 작물체로의 전이)

  • Choi, Yong-Ho;Lim, Kwang-Muk;Jun, In;Keum, Dong-Kwon
    • Journal of Radiation Protection and Research
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    • 제33권3호
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    • pp.105-112
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    • 2008
  • To measure the soil-to-plant transfer factors ($TF_a,\;m^2\;kg^{-1}$-fresh) of radionuclides deposited during the growing season of potato, a radioactive solution containing $^{54}Mn,\;^{60}Co,\;^{85}Sr$ and $^{137}Cs$ was applied to the soil surfaces in soil boxes 2 d before seeding and three different times during the plant growth. For the pre-seeding application (PSA), radionuclides were mixed with the topsoil (loamy sand and 5.2 in pH). The plant parts investigated were leaves, stems, tuber skin and tuber flesh. The $TF_a$ values of $^{54}Mn,\;^{60}Co,\;^{85}Sr$ and $^{137}Cs$ from the PSA were in the ranges of $1.9{\times}10^{-4}{\sim}1.5{\times}10^{-2}$, $1.8{\times}10^{-4}{\sim}7.5{\times}10^{-4}$, $4.0{\times}10^{-4}{\sim}1.6{\times}10^{-2}$, $1.5{\times}10^{-4}{\sim}3.9{\times}10^{-4}$ respectively, for different plant parts. The TFa values from the growing-time applications were on the whole a few times lower than those from the PSA. For $^{54}Mn,\;^{85}Sr$ and $^{137}Cs$, the $TF_a$ values from the early- or middle-growth-stage application were higher than those from the late-growth-stage application, whereas the opposite was true for $^{60}Co$. Leaves and tuber flesh had the highest and lowest $TF_a$ values, respectively, in most cases. The total uptake from soil by the four plant parts was in the range of $0.05{\sim}3.16%$. In the third year following the PSA, the $TF_a$ values of $^{54}Mn,\;^{60}Co$ and $^{137}Cs$ were $11{\sim}25%$, $21{\sim}25%$ and $38{\sim}67%$ of those in the first year, respectively, depending on the plant parts. The present results can be used for estimating the radiological impact of an acute radioactive deposition during the growing season of potato and for testing the validity of relevant food-chain models.

Trend and Further Research of Rice Quality Evaluation (쌀의 품질평가 현황과 금후 연구방향)

  • Son, Jong-Rok;Kim, Jae-Hyun;Lee, Jung-Il;Youn, Young-Hwan;Kim, Jae-Kyu;Hwang, Hung-Goo;Moon, Hun-Pal
    • KOREAN JOURNAL OF CROP SCIENCE
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    • 제47권
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    • pp.33-54
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    • 2002
  • Rice quality is much dependent on the pre-and post harvest management. There are many parameters which influence rice or cooked rice qualitys such as cultivars, climate, soil, harvest time, drying, milling, storage, safety, nutritive value, taste, marketing, eating, cooking conditions, and each nations' food culture. Thus, vice evaluation might not be carried out by only some parameters. Physicochemical evaluation of rice deals with amy-lose content, gelatinizing property, and its relation with taste. The amylose content of good vice in Korea is defined at 17 to 20%. Other parameters considered are as follows; ratio of protein body-1 per total protein amount in relation to taste, and oleic/linoleic acid ratio in relation to storage safety. The rice higher Mg/K ratio is considered as high quality. The optimum value is over 1.5 to 1.6. It was reported that the contents of oligosaccharide, glutamic acid or its derivatives and its proportionalities have high corelation with the taste of rice. Major aromatic compounds in rice have been known as hexanal, acetone, pentanal, butanal, octanal, and heptanal. Recently, it was found that muco-polysaccharides are solubilized during cooking. Cooked rice surface is coated by the muco-polysaccharide. The muco-polysaccharide aye contributing to the consistency and collecting free amino acids and vitamins. Thus, these parameters might be regarded as important items for quality and taste evaluation of rice. Ingredients of rice related with the taste are not confined to the total rice grain. In the internal kernel, starch is main component but nitrogen and mineral compounds are localized at the external kernel. The ingredients related with taste are contained in 91 to 86% part of the outside kernel. For safety that is considered an important evaluation item of rice quality, each residual tolerance limit for agricultural chemicals must be adopted in our country. During drying, rice quality can decline by the reasons of high drying temperature, overdrying, and rapid drying. These result in cracked grain or decolored kernel. Intrinsic enzymes react partially during the rice storage. Because of these enzymes, starch, lipid, or protein can be slowly degraded, resulting in the decline of appearance quality, occurrence of aging aroma, and increased hardness of cooked rice. Milling conditions concerned with quality are paddy quality, milling method, and milling machines. To produce high quality rice, head rice must contain over three fourths of the normal rice kernels, and broken, damaged, colored, and immature kernels must be eliminated. In addition to milling equipment, color sorter and length grader must be installed for the production of such rice. Head rice was examined using the 45 brand rices circulating in Korea, Japan, America, Australia, and China. It was found that the head rice rate of brand rice in our country was approximately 57.4% and 80-86% in foreign countries. In order to develop a rice quality evaluation system, evaluation of technics must be further developed : more detailed measure of qualities, search for taste-related components, creation and grade classification of quality evaluation factors at each management stage of treatment after harvest, evaluation of rice as food material as well as for rice cooking, and method development for simple evaluation and establishment of equation for palatability. On policy concerns, the following must be conducted : development of price discrimination in conformity to rice cultivar and grade under the basis of quality evaluation method, fixation of head rice branding, and introduction of low temperature circulation.

Study on High Sensitivity Metal Oxide Nanoparticle Sensors for HNS Monitoring of Emissions from Marine Industrial Facilities (해양산업시설 배출 HNS 모니터링을 위한 고감도 금속산화물 나노입자 센서에 대한 연구)

  • Changhan Lee;Sangsu An;Yuna Heo;Youngji Cho;Jiho Chang;Sangtae Lee;Sangwoo Oh;Moonjin Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • 제28권spc호
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    • pp.30-36
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    • 2022
  • A sensor is needed to continuously and automatically measure the change in HNS concentration in industrial facilities that directly discharge to the sea after water treatment. The basic function of the sensor is to be able to detect ppb levels even at room temperature. Therefore, a method for increasing the sensitivity of the existing sensor is proposed. First, a method for increasing the conductivity of a film using a conductive carbon-based additive in a nanoparticle thin film and a method for increasing ion adsorption on the surface using a catalyst metal were studied.. To improve conductivity, carbon black was selected as an additive in the film using ITO nanoparticles, and the performance change of the sensor according to the content of the additive was observed. As a result, the change in resistance and response time due to the increase in conductivity at a CB content of 5 wt% could be observed, and notably, the lower limit of detection was lowered to about 250 ppb in an experiment with organic solvents. In addition, to increase the degree of ion adsorption in the liquid, an experiment was conducted using a sample in which a surface catalyst layer was formed by sputtering Au. Notably, the response of the sensor increased by more than 20% and the average lower limit of detection was lowered to 61 ppm. This result confirmed that the chemical resistance sensor using metal oxide nanoparticles could detect HNS of several tens of ppb even at room temperature.

Customized Evacuation Pathfinding through WSN-Based Monitoring in Fire Scenarios (WSN 기반 화재 상황 모니터링을 통한 대피 경로 도출 알고리즘)

  • Yoon, JinYi;Jin, YeonJin;Park, So-Yeon;Lee, HyungJune
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제41권11호
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    • pp.1661-1670
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    • 2016
  • In this paper, we present a risk prediction system and customized evacuation pathfinding algorithm in fire scenarios. For the risk prediction, we apply a multi-level clustering mechanism using collected temperature at sensor nodes throughout the network in order to predict the temperature at the time that users actually evacuate. Based on the predicted temperature and its reliability, we suggest an evacuation pathfinding algorithm that finds a suitable evacuation path from a user's current location to the safest exit. Simulation results based on FDS(Fire Dynamics Simulator) of NIST for a wireless sensor network consisting of 47 stationary nodes for 1436.41 seconds show that our proposed prediction system achieves a higher accuracy by a factor of 1.48. Particularly for nodes in the most reliable group, it improves the accuracy by a factor of up to 4.21. Also, the customized evacuation pathfinding based on our prediction algorithm performs closely with that of the ground-truth temperature in terms of the ratio of safe nodes on the selected path, while outperforming the shortest-path evacuation with a factor of up to 12% in terms of a safety measure.