• Title/Summary/Keyword: bias effect

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Description of Kinetic Behavior of Pathogenic Escherichia coli in Cooked Pig Trotters under Dynamic Storage Conditions Using Mathematical Equations

  • Ha, Jimyeong;Lee, Jeeyeon;Oh, Hyemin;Kim, Hyun Jung;Choi, Yukyung;Lee, Yewon;Kim, Yujin;Lee, Heeyoung;Kim, Sejeong;Yoon, Yohan
    • Food Science of Animal Resources
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    • v.40 no.6
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    • pp.938-945
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    • 2020
  • A dynamic model was developed to predict the Escherichia coli cell counts in pig trotters at changing temperatures. Five-strain mixture of pathogenic E. coli at 4 Log CFU/g were inoculated to cooked pig trotter samples. The samples were stored at 10℃, 20℃, and 25℃. The cell count data was analyzed with the Baranyi model to compute the maximum specific growth rate (μmax) (Log CFU/g/h) and lag phase duration (LPD) (h). The kinetic parameters were analyzed using a polynomial equation, and a dynamic model was developed using the kinetic models. The model performance was evaluated using the accuracy factor (Af), bias factor (Bf), and root mean square error (RMSE). E. coli cell counts increased (p<0.05) in pig trotter samples at all storage temperatures (10℃-25℃). LPD decreased (p<0.05) and μmax increased (p<0.05) as storage temperature increased. In addition, the value of h0 was similar at 10℃ and 20℃, implying that the physiological state was similar between 10℃ and 20℃. The secondary models used were appropriate to evaluate the effect of storage temperature on LPD and μmax. The developed kinetic models showed good performance with RMSE of 0.618, Bf of 1.02, and Af of 1.08. Also, performance of the dynamic model was appropriate. Thus, the developed dynamic model in this study can be applied to describe the kinetic behavior of E. coli in cooked pig trotters during storage.

Comparison of Safety Margin of Shallow Foundation on Weathered Soil Layer According to Design Methods (설계법에 따른 풍화토 지반 얕은기초의 안전여유 비교)

  • Kim, Donggun;Hwang, Huiseok;Yoo, Namjae
    • Journal of the Korean GEO-environmental Society
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    • v.17 no.12
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    • pp.55-64
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    • 2016
  • In this paper bearing capacity and safety margin of shallow foundation on weathered soil ground against shear failure by using current design method of allowable stress design (ASD), load resistance factor design (LRFD) based on reliability analysis and partial safety factor design (PSFD) in Eurocode were estimated and compared to each other. Results of the plate loading test used in construction and design were collected and analysis of probability statistics on soil parameters affecting the bearing capacity of shallow foundation was performed to quantify the uncertainty of them and to investigate the resistance bias factor and covalence of ultimate bearing capacity. For the typical sections of shallow foundation in domestic field as examples, reliability index was obtained by reliability analysis (FORM) and the sensitivity analysis on soil parameters of probability variables was performed to investigate the effect of probability variable on shear failure. From stability analysis for these sections by ASD, LRFD with the target reiability index corresponding to the safety factor used in ASD and PSDF, safety margins were estimated respectively and compared.

Magnetoresistance of Single-type and Dual-type GMR-SV Multilayer Thin Films with Top and Bottom IrMn Layer (상부와 하부 IrMn층을 갖는 단일구조 및 이중구조 거대자기저항-스핀밸브 다층박막의 자기적 특성 비교 분석)

  • Choi, Jong-Gu;Kim, Su-Hee;Choi, Sang-Heon;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
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    • v.27 no.4
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    • pp.115-122
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    • 2017
  • The antiferromagnet IrMn based four different GMR-SV multilayers on Corning glass were prepared by using ion beam deposition and DC magnetron sputtering system. The magnetoresistance (MR) properties for single-type and dual-type GMR-SV multilayer films were investigated through the measured major and minor MR curves. The exchange bias coupling field ($H_{ex}$) and coercivity ($H_c$) of pinned layer, the $H_c$ and interlayer exchange coupling field ($H_{int}$) of free layer for the dual-type structure GMR-SV multilayer films consisted of top IrMn layer were 410 Oe, 60 Oe, 1.6 Oe, and 7.0 Oe, respectively. The minor MR curve of two free layers was performed the squarelike feature having a MR ratio of 8.7 % as the sum of 3.7 % and 5.0 %. The value of average magnetic field sensitivity (MS) was maintained at 2.0 %/Oe. Also, the magnetoresistance properties of the single-type and dual-type structure GMR-SV multilayer films consisted of bottom IrMn layer were decreased more than those of top IrMn layer. Two antiparallel states of magnetization spin arrays of the pinned and free layers in the dual-type GMR-SV multilayer films occurred the maximum MR value by the effect of spin dependence scattering.

Effects of Acupuncture on patients with cold hypersensitivity by Cold Stress Test : pilot study (냉부하검사(CST)를 활용한 수부냉증의 침치료 효과에 대한 예비 연구)

  • Hwang, Deok-Sang;Cho, Jung-Hoon;Lee, Chang-Hoon;Jang, Jun-Bock;Kim, Yong-Seok;Lee, Kyung-Sub;Lee, Yoon-Jae
    • Journal of Oriental Medical Thermology
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    • v.5 no.1
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    • pp.69-77
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    • 2006
  • Purpose : There are many patients with cold hypersensitivity who want oriental medicine treatment. But there has been no study of acupucture treatment effect on patients. So we examined effects of acupuncture treatment at different acupuncture points and compared results of 1st cold stress test and 2nd cold stress test. Method : 8 patients with hand cold hypersensitivity applied for this study. To rule out an bias, we excluded the patients with skin diseases, spinal nerve disease of cervial spine, external wounds. We measured body temperature with D.I.T.I. We performed cold stress test(CST) by 6 thermographic observation using D.I.T.I ; the 1st was taken after 15 minutes-resting, the 2nd was immediately taken after 1 minute soak in $20^{\circ}C$ water, the 3rd was taken at 10 minutes after the soak, and after a week, the 4th was taken after 15 minutes resting, the 5th was immediately taken after 1 minute soak in $20^{\circ}C$ water, the 6th was taken after 10 minutes with acupunture treatment. There were two groups of patients. First group was acupuncture that performed acupuncture therapy on distal points. Second group was acupuncture that performed acupuncture therapy on proximal points. We compared first CST and second CST recovery rate result. Results : The recovery rate at distal points acupuncture therapy was higher than before of that. but not significantly different. The recovery rate at proximal points acupuncture therapy was significantly higher than before of that. The recovery rate of both the back, the palms, all fingers of after proximal acupuncture therapy was significantly higher than before of that. Conclusions : Acupuncture could be effective therapy method on cold hypersensitivity, especially using proximal acupuncture points could be good at cold hypersensitivity patients. This was pilot study of very small samples, results had limitations. For further results more examine would be needed.

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The Interpretation of Different Recreation Benefits According to Time Horizon in the Contingent Valuation Method (가상가치평가법(假想價値評價法)에서 시간범위(時間範圍)에 따른 휴양가치(休養價値)의 차이(差異) 해석(解析))

  • Kim, Joon-Soon
    • Journal of Korean Society of Forest Science
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    • v.88 no.1
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    • pp.117-123
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    • 1999
  • Consumer surplus is to be a value concerning a time horizon. Especially it is very important how long time horizon would be chosen in contingent market. This study aimed to provide causes of difference recreation benefits through discount rate in many aspects. The data were collected by personal interviews with visitors in Songnisan National Park. The respondents answered yes or no, dichotomous choice, on recreation benefits according to a chosen time horizon, one year or five years. The probit model was used in the analysis. In order to avoid the truncation bias of upper bound, the median was chosen as the recreation benefits of visitor. As the result, the value was evaluated to be 16,569 Won for one year and 27,111 Won for five years. The discount rate is estimated 153% annually to coincide different recreation benefits. The reasons of the high discount rate were to be interpreted as following five types : (1)uncertainty of future consumption (2)increasing of probability of the substitution owing to increasing of time horizon (3)recognization of different time horizons (4) effect by the price ratio of goods and utility function (5) overestimation of the recreation benefits owing to a basic premium of payment vehicle.

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A Study on the Reformation of Evaluation System for Goodwill under the Current Tax Law (현행 세법상 영업권 평가제도의 개선방안에 관한 연구)

  • Kwak, Young-Min
    • Management & Information Systems Review
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    • v.32 no.1
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    • pp.195-216
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    • 2013
  • This Study investigates evaluation policies for goodwill under the current tax law and suggests improvements as follows. First, even though not appear on the financial statements of acquiree at the date of acquisition, the current corporate tax raw regulates that firms need to estimate purchased goodwill including acquisition amount and additionally recognizable intangible property right with no distinction. According to this rule, purchased goodwill from business combination under the current tax raw has a drawback in overestimating. So, there is need of further improvement on the current related purchased goodwill regime to distinguish additionally recognized intangible property right from purchased goodwill. Second, in the consideration of internally generated goodwill, suggested in the current inheritance and gift tax act as a supplementary evaluation technique, the estimated value of goodwill may contain some bias, since the current regulation uniformly applies to all the companies with no industry characteristics. This may particularly become problematic while computing abnormal earnings, uniformly applying the 10% normal return to all the companies since the normal return is not likely to reflect industry characteristics and thus the computed abnormal earnings may be biased. Therefore, there is need to revise the current regulation relating to the normal return, to convert from the existing 10% rule to the industry average rate of return method.

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The Effect of Auricular Acupuncture for Obesity: A Systematic Review and Meta-analysis (비만치료에 대한 이침요법의 효과에 대한 고찰: 체계적 문헌고찰 및 메타분석)

  • Park, Seohyun;An, Sunjoo;Choi, Sunghwan;Kang, Shinwoo;Keum, Dongho
    • Journal of Korean Medicine for Obesity Research
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    • v.20 no.1
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    • pp.52-68
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    • 2020
  • Objectives: The purpose of this study is to investigate the weight loss effects of auricular acupuncture in obese patients. Methods: Six databases (Research Information Sharing Service [RISS], Korean studies Information Service System [KISS], Oriental Medicine Advanced Searching Integrated System [OASIS], PubMed, The Cochrane Library, China National Knowledge Infrastructure [CNKI]) were searched up to May 20, 2020. Eight eligible randomized controlled trials were included the present study. The quality of included studies was assessed by the Cochrane risk of bias tool and a meta-analysis was performed by Review Manager software. A meta-analysis was conducted using a random-effects model and a subgroup analysis was performed to detect the sources of heterogeneity, identify the selection of acupuncture methods and explore its contributions to the weight loss effects. Results: Among 8 trials, 5 trials used auricular acupuncture and 2 trials used auricular acupressure, 1 trial used both types of intervention. Most commonly selected acupoints were Shenmen (TF4) and stomach (CO4). Treatment duration was six to twelve weeks, and total treatment session was six to twelve. Compared to the control groups, auricular acupuncture significantly decreased body weight, body mass index (BMI), high density lipoprotein-cholesterol (HDL) and ghrelin. For the selection of acupuncture methods, both methods performed similarly in most outcome except waist circumference (WC), body fat percentage (BFP), and triglycerides (TG). Conclusions: We found that auricular acupuncture can be effective for weight loss and controlling appetite. However, the findings should be interpreted with caution due to heterogeneity. So further vigorous and well-designed studies should be conducted to strengthen the evidence of the use of auricular acupuncture for obesity.

Mathematical modeling of growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds (적콜라비 새싹채소 종자에서 분리한 Escherichia coli strain RC-4-D의 생장예측모델)

  • Choi, Soo Yeon;Ryu, Sang Don;Park, Byeong-Yong;Kim, Se-Ri;Kim, Hyun-Ju;Lee, Seungdon;Kim, Won-Il
    • Food Science and Preservation
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    • v.24 no.6
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    • pp.778-785
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    • 2017
  • This study was conducted to develop a predictive model for the growth of Escherichia coli strain RC-4-D isolated from red kohlrabi sprout seeds. We collected E. coli kinetic growth data during red kohlrabi seed sprouting under isothermal conditions (10, 15, 20, 25, and $30^{\circ}C$). Baranyi model was used as a primary order model for growth data. The maximum growth rate (${\mu}max$) and lag-phase duration (LPD) for each temperature (except for $10^{\circ}C$ LPD) were determined. Three kinds of secondary models (suboptimal Ratkowsky square-root, Huang model, and Arrhenius-type model) were compared to elucidate the influence of temperature on E. coli growth rate. The model performance measures for three secondary models showed that the suboptimal Huang square-root model was more suitable in the accuracy (1.223) and the suboptimal Ratkowsky square-root model was less in the bias (0.999), respectively. Among three secondary order model used in this study, the suboptimal Ratkowsky square-root model showed best fit for the secondary model for describing the effect of temperature. This model can be utilized to predict E. coli behavior in red kohlrabi sprout production and to conduct microbial risk assessments.

A Polarization-Switchable Microstrip Patch Antenna Using Corner Slots on Ground Plane and PIN Diodes (모서리 접지면 슬롯과 PIN 다이오드를 이용한 편파 변환 마이크로스트립 안테나)

  • Park, Chul-Woo;Lee, Tae-Hak;Choi, Jun-Ho;Yoon, Won-Sang;Pyo, Seong-Min;Kim, Young-Sik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.7
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    • pp.769-777
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    • 2010
  • In this paper, a switchable circularly polarized microstrip patch antenna using PIN diodes and corner slots on ground plane is proposed at 2.4 GHz. The proposed antenna has a square microstrip patch and ground plane that consists of two pair of slots and PIN diodes. The electrical lengths of the slots are adjusted by using the switching characteristic of the PIN diode, so the polarization of the proposed antenna can be switchable between linear, left-handed(LH) and right-handed(RH). By separating the ground plane for the DC bias, the size reduction effect is also obtained. When the proposed antenna is operated as linear polarization, the return loss and impedance bandwidth are 15 dB, 59 MHz, and when operated as LH and RH polarization, the minimum axial ratio and 3-dB axial ratio bandwidth are 1.17 dB, 1.67 dB, 28 MHz, and 32 MHz, respectively.

Effect of DC bias on structure of hydrogenated amorphous silicon and microcrystalline silicon

  • 이윤정;주성재;임승현;윤의준
    • Proceedings of the Korean Vacuum Society Conference
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    • 2000.02a
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    • pp.84-84
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    • 2000
  • 수소화된 비정질 실리콘(a-Si:H)과 미세결정질 실리콘 ($\mu$c-Si:H)은 저온.건식 공정인 PECVD로 값싼 유리 기판을 사용하여 넓은 면적에 증착이 가능하다는 큰 장점으로 인해 광전소자(photovoltaic device)와 박막 트랜지스터(TFTs)등에 폭넓게 응용되어 왔으며 최근에는 nm 크기의 실리콘 결정(nc-Si)에서 가시광선 영역의 발광 현상이 발견됨에 따라 광소자로서의 특성을 제어하기 위해서는 성장 조건과 공정 변수에 따른 구조 변화에 대한 연구가 선행되어야 한다. 본 연구에서는 UHV-ECR-PECVD 법을 이용하여 H2로 희석된 SiH4로부터 a-Si:H과 $\mu$c-Si:H를 증착하였다. 그림 1은 SiH4 20sccm/H2 50sccm/25$0^{\circ}C$에서 기판의 DC bias를 변화시키면서 박막을 증착시킬 때 나타나는 박막의 구조 변화를 raman spectrum의 To phonon peak의 위치와 반가폭의 변화로 나타낸 것이다. 비정질 실리콘 박막은 DC bias를 증가시킴에 따라 무질서도가 증가하다가 어떤 critical DC bias에서 최대치를 이룬후 다시 질서도가 증가한다. 이온의 충격력에 의해 박막내에 응력이 축적되면 박막의 에너지 상태가 높아지고 이 축적된 응력이 ordering에 대한 에너지 장벽을 넘을 수 있을 만큼 커지게 되면 응력이 풀리면서 ordering이 가능해지는 것으로 생각된다. 그림 2는 수소 결합 형태의 변화이다. 박막의 무질서도가 증가할 경우 알려진 바와 같이 2000cm-1근처의 peak은 감소하고 2100cm-1 부근이 peak이 증가하는 현상을 보였다. 본 논문에서는 여러 공정 변수, 특히 DC bias에 따르는 박막의 구조 변화와 다른 성장 조건(온도, 유량비)이 critical DC bias나 결정화, 결정성 등에 미치는 영향에 대한 분석결과를 보고하고자 한다.등을 이용하여 광학적 밴드갭, 광흡수 계수, Tauc Plot, 그리고 파장대별 빛의 투과도의 변화를 분석하였으며 각 변수가 변화함에 따라 광학적 밴드갭의 변화를 정량적으로 조사함으로써 분자결합상태와 밴드갭과 광 흡수 계수간의상관관계를 규명하였고, 각 변수에 따른 표면의 조도를 확인하였다. 비정질 Si1-xCx 박막을 증착하여 특성을 분석한 결과 성장된 박막의 성장률은 Carbonfid의 증가에 따라 다른 성장특성을 보였고, Silcne(SiH4) 가스량의 감소와 함께 박막의 성장률이 둔화됨을 볼 수 있다. 또한 Silane 가스량이 적어지는 영역에서는 가스량의 감소에 의해 성장속도가 둔화됨을 볼 수 있다. 또한 Silane 가스량이 적어지는 영역에서는 가스량의 감소에 의해 성장속도가 줄어들어 성장률이 Silane가스량에 의해 지배됨을 볼 수 있다. UV-VIS spectrophotometer에 의한 비정질 SiC 박막의 투과도와 파장과의 관계에 있어 유리를 기판으로 사용했으므로 유리의투과도를 감안했으며, 유리에 대한 상대적인 비율 관계로 투과도를 나타냈었다. 또한 비저질 SiC 박막의 흡수계수는 Ellipsometry에 의해 측정된 Δ과 Ψ값을 이용하여 시뮬레이션한 결과로 비정질 SiC 박막의 두께를 이용하여 구하였다. 또한 Tauc Plot을 통해 박막의 optical band gap을 2.6~3.7eV로 조절할 수 있었다. 20$0^{\circ}C$이상으로 증가시켜도 광투과율은 큰 변화를 나타내지 않았다.부터 전분-지질복합제의 형성 촉진이 시사되었다.이것으로 인하여 호화억제에 의한 노화 방지효과가 기대되었지만 실제로 빵의 노화는 현저히 진행되었다. 이것은 quinua 대체량 증가에 따른 반죽의 안정성이 저하되어 버린 것으로 생각되어진다. 더욱이 lipase를 첨가하면 반죽이 분화하는 경향이 보여졌지만 첨가량 75ppm에 있어서 상당히 비용적의 증대가 보였다. 이것은 lipase의 가수분해에 의해

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