• Title/Summary/Keyword: Decay time

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A Study on the Establishment of Entropy Source Model Using Quantum Characteristic-Based Chips (양자 특성 기반 칩을 활용한 엔트로피 소스 모델 수립 방법에 관한 연구)

  • Kim, Dae-Hyung;Kim, Jubin;Ji, Dong-Hwa
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.140-142
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    • 2021
  • Mobile communication technology after 5th generation requires high speed, hyper-connection, and low latency communication. In order to meet technical requirements for secure hyper-connectivity, low-spec IoT devices that are considered the end of IoT services must also be able to provide the same level of security as high-spec servers. For the purpose of performing these security functions, it is required for cryptographic keys to have the necessary degree of stability in cryptographic algorithms. Cryptographic keys are usually generated from cryptographic random number generators. At this time, good noise sources are needed to generate random numbers, and hardware random number generators such as TRNG are used because it is difficult for the low-spec device environment to obtain sufficient noise sources. In this paper we used the chip which is based on quantum characteristics where the decay of radioactive isotopes is unpredictable, and we presented a variety of methods (TRNG) obtaining an entropy source in the form of binary-bit series. In addition, we conducted the NIST SP 800-90B test for the entropy of output values generated by each TRNG to compare the amount of entropy with each method.

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Extraction of Snowmelt Parameters using NOAA AVHRR and GIS Technique for 7 Major Dam Watersheds in South Korea (NOAA AVHRR 영상 및 GIS 기법을 이용한 국내 주요 7개 댐 유역의 융설 매개변수 추출)

  • Shin, Hyung Jin;Kim, Seong Joon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.2B
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    • pp.177-185
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    • 2008
  • Accurate monitoring of snow cover is a key component for studying climate and global as well as for daily weather forecasting and snowmelt runoff modelling. The few observed data related to snowmelt was the major cause of difficulty in extracting snowmelt factors such as snow cover area, snow depth and depletion curve. Remote sensing technology is very effective to observe a wide area. Although many researchers have used remote sensing for snow observation, there were a few discussions on the characteristics of spatial and temporal variation. Snow cover maps were derived from NOAA AVHRR images for the winter seasons from 1997 to 2006. Distributed snow depth was mapped by overlapping between snow cover maps and interpolated snowfall maps from 69 meteorological observation stations. Model parameters (Snow Cover Area: SCA, snow depth, Snow cover Depletion Curve: SDC) were built for 7 major watersheds in South Korea. The decrease pattern of SCA for time (day) was expressed as exponentially decay function, and the determination coefficient was ranged from 0.46 to 0.88. The SCA decreased 70% to 100% from the maximum SCA when 10 days passed.

Experimental Investigation of Aerodynamic Force Coefficients and Flutter Derivatives of Bridge Girder Sections (교량단면의 공기력계수 및 플러터계수에 관한 실험적 연구)

  • Cho, Jae-Young;Lee, Hak-Eun;Kim, Young-Min
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5A
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    • pp.887-899
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    • 2006
  • The aim of this study is to investigate a correlation between fundamental data on aerodynamic characteristics of bridge girder cross-sections, such as aerodynamic force coefficients and flutter derivatives, and their aerodynamic behaviour. The section model tests were carried out in three stages. In the first stage, seven deck configurations were studied, namely; Six 2-edge girders and one box girder. In this stage, changes in aerodynamic force coefficients due to geometrical shape of girders, incidence angle of flow, wind directions and turbulence intensities were studied by static section model tests. In the second stage, the dynamic section model tests were carried out to investigate the relativity of static coefficients to dynamic responses. And finally, the two-dimensional (lift-torsion) aerodynamic derivatives of three bridge deck configurations were investigated by dynamic section model tests. The aerodynamic derivatives can be best described as a representation of the aerodynamic damping and the aerodynamic stiffness provided by the wind for a given deck geometry. The method employed here to extract these unsteady aerodynamic properties is known as the initial displacement technique. It involves the measurement of the decay in amplitude with time of an initial displacement of the deck in heave and torsion, for various wind speeds, in smooth flow. It is suggested that the proposed aerodynamic force coefficients and flutter derivatives of bridge girder sections will be potentially useful for the aeroelastic analysis and buffeting analysis.

Recent Research Status of Postharvest Management of Broccoli (브로콜리 수확후 관리의 최근 연구 동향)

  • Choi, Ji-Weon;Lee, Woo-Moon;Kwak, Jung-Ho;Kim, Won-Bae;Kim, Ji-Gang;Lee, Seung-Ku;Cho, Mi-Ae
    • Journal of the Korean Society of International Agriculture
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    • v.23 no.5
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    • pp.497-502
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    • 2011
  • Broccoli is considered as one of the functional foods to offer a hearty supply of the nutrient-rich vegetable in the world. Broccoli contains high level of phytochemicals, and that is selected as one of the top 10 vegetables for human health promotion. Especially, glucosinolates and flavonoids are well known as anti free oxygen radicals in vegetables and fruits. In Korea, broccoli consumption has increased to well known on the health-beneficial vegetables since 2000. However, broccoli has many problems of postharvest management since the quality of harvested heads quickly declines. Major problems are the floret yellowing, wilting, off-odor, and decay. The multiple postharvest applications improve broccoli quality and cold treatment including pre-cooling extends on the shelf-life with circumstance of optimum storage which is 0℃ temperature and a range of 95-100% relative humidity. Controlled atmosphere or modified atmosphere packaging can be used as supplemental treatments to extend postharvest life. 1-2% O2 + 5-10% CO2 is currently recommended for broccoli. Postharvest management is important for broccoli because price fluctuations depend on harvest time and quality. In this study, we tried to review physiological change of broccoli after the harvest, storage method, and various techniques to optimize quality during distribution.

Comparative Study on Phenolic Compounds of Cheorwon Onion by Phosphite Treatment (아인산염 처리에 따른 철원양파의 페놀화합물 비교 연구)

  • Kim, Y.B.;Lee, H.J.;Park, C.H.;Kim, D.H.;Koo, H.J.;Chang, K.J.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.20 no.2
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    • pp.105-114
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    • 2018
  • The aim of this study was to evaluate the change of phenolic compounds after phosphite treatment on Cheorwon onion. Onion is a perennial plant belonging to the lily family. It is native to Persia of Southwest Asia. It is widely cultivated in the temperate regions of the world. Onion is a good name for the 'Okchong' to drop blood cholesterol and cardiovascular blood flow to increase the prevention of adult diseases. Cheorwon area is inland, but it has high continental climate due to its high altitude. Therefore it is said that the onion cultivated in this region has higher sugar content and higher taste than onion grown in the southern region. Phosphorus components are particularly important ingredients for promoting muscle development. However, if the phosphoric acid content of the soil part is maintained to a large extent until the harvest, the competition of the nutrients tends to cause decay of the root part. Therefore, it is important to improve the quality and shelf life of onion by inducing nutrient balance by applying foliar fertilization method on the reducing phosphorus at harvest time. In this study, acidity was controlled by diluting phosphorous acid(H3PO3) and potassium hydroxide(KOH), followed by leaf surface treatment with phosphite on onion. In this study, the concentration of phosphite was diluted to 500, 1,000, 1,500ppm and sprayed three times over the onion leaves in May 2018 using an atomizer and harvested at the end of June, and the phenolic compounds were analyzed by HPLC. As a result, the content of quercetin, one of the important substances in onion, was phosphite 500ppm(179.70㎍/g), 1,000(150.27), 1,500(105.95). The contents of caffeic acid, p-coumaric acid, ferulic acid, rutin, kaempferol, and sugar content were higher in the treatments than in the control. Therefore, the phosphite does not have a great influence on the growth, but it may play a role as a method of achieving balance with nitrogen in the rainy season by supplying the role of the material catalyst and the water soluble phosphoric acid and the potassium in the influence of the material change.

'Han of the Class' based on the Relationship between Character and Non-Character Symbols - on the Film of Bong Joon-ho - (인물 기호와 비인물 기호 관계를 바탕으로 한 '계급의 한' -봉준호 영화를 중심으로-)

  • Song-lin Zhao;Yoojin Kim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.2
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    • pp.323-331
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    • 2024
  • The concept of 'Han' is a psychological characteristic formed by Koreans through long-lasting national hardships. It has deeply influenced every Korean as a form of collective unconscious and has merged with various forms of art over time. Director Bong Joon-ho's works, rich in social consciousness, symbolically visualize sensitive issues like social class, presenting harsh satire on class oppression. His movies continuously emphasize human desires, the homogeneity of good and evil, insurmountable class barriers, and moral decay caused by desires. They produce a wealth of symbols filled with layers and power dynamics. Bong Joon-ho dramatically portrays and directs various forms of symbols. The metaphorical symbols in his movies provide a unique research value for delving into the deeper meanings of the films.This study examines the theme of 'class Han' in six of Bong Joon-ho's films, exploring the 'Han culture' of Korea. It applies semiotic concepts by categorizing into character and non-character symbols for an in-depth analysis of the films. The representative works from the late 1990s to the late 2010s articulate the class layers of the 'visible' and the 'invisible' through a blend of realism and surrealism. The study analyzes Bong Joon-ho's films in the sequence of 'satire-exposure-hope', examining the culturally critical nature of 'Han culture' on class and its psychological and cultural impact on the general public.

Development of a Synthetic Method for [68Ga]Ga-FAPI-04 Using a Cassette-based Synthesizer (카세트 기반 자동합성장치를 사용한 [68Ga]Ga-FAPI-04의 합성방법 연구)

  • Jun Young PARK;Won Jun KANG
    • Korean Journal of Clinical Laboratory Science
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    • v.56 no.1
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    • pp.43-51
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    • 2024
  • [68Ga]Ga-FAPI-04 is a promising radiopharmaceutical that binds specifically to fibroblast activation protein, which is overexpressed in more than 90% of malignant epithelial tumors but not in normal healthy tissue. This study aimed to develop an efficient method for producing 68Ga-labelled FAPI-04 using a cassette-based automated synthesizer. [68Ga]GaCl3 was eluted from an Eckert & Ziegler Medical germanium-68/gallium-68 generator using 2.5 mL of 0.1 M HCl. The synthesis of the [68Ga]Ga-FAPI-04 was performed using different concentrations of HEPES (1~2.5 M; 4-(2-hydroxyethyl) piperazine-1-ethanesulfonic acid) in 3~10 minutes; amounts of FAPI-04 precursor (5~50 ㎍) and reaction temperature (25℃~100℃) were optimized on the BIKBox® synthesizer. The labeling efficiency of [68Ga]Ga-FAPI-04 was greater than 96% (decay corrected) using 25 ㎍ FAPI-04 synthesized in 10 minutes at 100℃ in 2 M HEPES (pH 3.85), and its stability was greater than 99% at 6 hours. The total synthesis time of [68Ga]Ga-FAPI-04 was 32.4 minutes, and the product met all quality control criteria. In this study, we developed and optimized a labeling method using [68Ga]Ga-FAPI-04 using a cassette-based synthesizer. The devised method is expected to be useful for supplying [68Ga]Ga-FAPI-04 for diagnosis in clinical practice.

Dst Prediction Based on Solar Wind Parameters (태양풍 매개변수를 이용한 Dst 예측)

  • Park, Yoon-Kyung;Ahn, Byung-Ho
    • Journal of Astronomy and Space Sciences
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    • v.26 no.4
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    • pp.425-438
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    • 2009
  • We reevaluate the Burton equation (Burton et al. 1975) of predicting Dst index using high quality hourly solar wind data supplied by the ACE satellite for the period from 1998 to 2006. Sixty magnetic storms with monotonously decreasing main phase are selected. In order to determine the injection term (Q) and the decay time ($\tau$) of the equation, we examine the relationships between $Dst^*$ and $VS_s$, ${\Delta}Dst^*$ and $VS_s$, and ${\Delta}Dst^*$ and $Dst^*$ during the magnetic storms. For this analysis, we take into account one hour of the propagation time from the ACE satellite to the magnetopause, and a half hour of the response time of the magnetosphere/ring current to he solar wind forcing. The injection term is found to be $Q(nT/h)\;=\;-3.56VS_s$ for $VS_s$ > 0.5mV/m and Q(nT=h) = 0 for $VB_s\;{\leq}\;0.5mV/m$. The $\tau$ (hour) is estimated as $0.060Dst^*\;+\;16.65$ for $Dst^*$ > -175nT and 6.15 hours for $Dst^*\;{\leq}\;-175nT$. Based on these empirical relationships, we predict the 60 magnetic storms and find that the correlation coefficient between the observed and predicted $Dst^*$ is 0.88. To evaluate the performance of our prediction scheme, the 60 magnetic storms are predicted again using the models by Burton et al. (1975) and O'Brien & McPherron (2000a). The correlation coefficients thus obtained are 0.85, the same value for both of the two models. In this respect, our model is slightly improved over the other two models as far as the correlation coefficients is concerned. Particularly our model does a better job than the other two models in predicting intense magnetic storms ($Dst^*\;{< \atop \sim}\;-200nT$).

Changes in Protease and Formonitrogen of Salted Fish and Shellfish (1) (젓갈 성숙과정(成熟過程)에 있어 Protease 및 Formonitrogen의 변화(變化)에 관(關)한 연구(硏究)(1))

  • Suh, Myung-Jah
    • Journal of Nutrition and Health
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    • v.6 no.2
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    • pp.45-56
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    • 1973
  • Salted fish and shellfish have been widely used in Korea from olden times as side-dishes, although the processes and methods of pickling have varied depending on localities. The common raw materials for these subsidiary food articles include anchovy, shrimp, yellow corvina, oysters, octopus, top-shell, shellfish, pollack roe and pollack intestines. It must be pointed out here, however, that the salted stuffs now marketed locally are highly unscientific and unsanitary in the way they are processed and sold, and this has prompted this writer to undertake a study on these native food articles. The following findings have been obtained from this study on the changes in Formonitrogen and Protease Activity, effected by the density of salt and the degree of storing temperature, of the pickles of cedfish gills, codfish intestines, pollack intestines, shellfish, oysters, cuttle fish and octopus. 1) Codfish Gills The Protease Activity of the pickled codfish gills was greater in the groups of lesser doses of salt and higher degrees of storing temperature. The same was true in the case of Formonifrogen, too. The Formonitrogen of the pickled codfish gills was larger in the groups of lesser salt and higher teimperature. 2) Codfish Intestines The amount of Formonitrogen of the pickled codfiah intestines became greater, as time went by, in the groups of lesser salt than those of larger doses of salt, with the speed of its formation getting faster as the storing temperature rose from $5^{\circ}C$ to $15^{\circ}C$ and $30^{\circ}C$. The Protease Activity was also greater in the groups of lesser salt and higher temperature. The group, stored at 10% salt and $30^{\circ}C$, rotted in five days. 3) Pollack Intestines The amount of Formonitrogen of the pickled pollack intestines was greater in the groups of lesser amount of salt and higher degrees of storing temperature. The Protease Activity of the pickled pollack intestines began decreasing from the 11th day after the pickling in the groups stored at colmparatively high degrees of temperature$(15^{\circ}C-30^{\circ}C)$, while that of the group stored at $5^{\circ}C$ kept rising. The effects of the amount of salt were little. The group stored at 15% salt and $30^{\circ}C$ started rotting on the 13th day while that stored at $30^{\circ}C$ decayed on the 7th day. The group stored at 20% salt and $30^{\circ}C$ rotted on the 9th day. 4) Oysters The amount of Formonitrogen of the pickled oysters became greater as the storing temperature rose and the doses of salt were lowered. The Protease Activity was not affected at any measurable degree by the density of salt in the group stored at $5^{\circ}C$, but became greater as the storing temperature rose to $15^{\circ}C$ and $30^{\circ}C$. The group stored at 10% salt and $30^{\circ}C$ rotted on the 5th day while that stored at 20% salt and $30^{\circ}C$ on the 13th day. 5) Shellfish The amount of Formonitrogen of the pickled shellfish became greater, as time went by, it the groups of lower consistency of salt than the groups of higher density of salt, although the decay of the former groups was faster than the latter groups. The density of salt best fitted for the pickling appeared to be about 20% with the storing temperature to be $15^{\circ}C$, at which the pickled stuff became most tasty on the 7th day. The oysters stored in three groups at $5^{\circ}C$, $15^{\circ}C$ and $30^{\circ}C$ respectively showed the greatest Protease Activity alike at 0% of salt, but the activity declined as the density of salt increased. The Protease Activity of each group rose for the first 11 days after the pickling, but began declining from the 13th day onward, with the groups of higher temperature retaining higher Protease Activity than the groups of lower temperature. 6) Cuttlefish Both the amount of Formonitrogen and the degree of Protease Activity of the pickled cuttlefish were greater in the groups of lower density of salt and higher degree of storing temperature. The oysters pickled at 10% salt and $15^{\circ}C$ degenerated on the 13th day while that of 10% salt and $30^{\circ}C$ deteriorated on the 7th day. 7) Octopus Both the Formonitrogen and the Protease Activity of the pickled octopus were greater in the groups of lower density of salt, but as time went by, the Protease Activity in all groups dwindled after a climbing. In general, the Formonitrogen and the Protease Activity of the pickled oysters became greater as the storing temperature got higher. One group stored at 10% salt and $15^{\circ}C$ rotted in 13days while another group stored at $30^{\circ}C$ decayed in 7 days.

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Growth and optical conductivity properties for MnAl2S4 single crystal thin film by hot wall epitaxy method (Hot Wall Epitaxy(HWE)법에 의한 MnAl2S4 단결정 박막 성장과 광전도 특성)

  • You, Sangha;Lee, Kijeong;Hong, Kwangjoon;Moon, Jongdae
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.24 no.6
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    • pp.229-236
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    • 2014
  • A stoichiometric mixture of evaporating materials for $MnAl_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MnAl_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $MnAl_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.7920eV-5.2729{\times}10^{-4}eV/K)T^2/(T+786 K)$. In order to explore the applicability as a photoconductive cell, we measured the sensitivity (${\gamma}$), the ratio of photocurrent to dark current (pc/dc), maximum allowable power dissipation (MAPD) and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in S vapour compare with in Mn, Al, air and vacuum vapour. Then we obtained the sensitivity of 0.93, the value of pc/dc of $1.10{\times}10^7$, the MAPD of 316 mW, and the rise and decay time of 14.8 ms and 12.1 ms, respectively.