Inverse calibration matrix algorithm for radiation detection portal monitors

Kim, Yewon,Kim, Myungsoo,Lim, Kyung Taek,Kim, Jongbum,Cho, Gyuseong Pergamon 2019 Radiation physics and chemistry Vol.155 No.-

<P><B>Abstract</B></P> <P>Radioisotope identification of an energy spectrum obtained from a radiation portal monitor (RPM) is a challenging task due to its insufficient data acquisition time. Thus, conventional algorithms for a radiation portal monitor, such as the gross count algorithm and the energy window algorithm, use the gross count of the measured spectrum or the gross counts of specific energy ranges. However, the conventional algorithms cause false alarms because they simply compare the gross count of the measured spectrum to the background radiation count. In this paper, an inverse calibration matrix (ICM) algorithm for radioisotope identification is proposed, which uses approaches different from those of conventional algorithms. To evaluate this method, various gamma energy spectra of <SUP>133</SUP>Ba, <SUP>137</SUP>Cs, <SUP>60</SUP>Co, <SUP>22</SUP>Na, background radiation and a potassium fertilizer that included <SUP>40</SUP>K were measured by four photomultipliers attached to a large-area polyvinyl-toluene (PVT) scintillator for a radiation portal monitor. The results demonstrated that the energy spectra obtained with measurement times ranging from 0.1 to 50 s were precisely identified by the ICM algorithm.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Inverse calibration matrix (ICM) algorithm for has been developed. </LI> <LI> Gamma energy spectra of various radioisotopes were measured. </LI> <LI> ICM algorithm is able to identify radioisotopes from measured energy spectra. </LI> </UL> </P>

이익분산과 회계투명성 정보를 활용한 거시경제지표 예측

김예원 ( Yewon Kim ),이용규 ( Yong Gyu Lee ),김휘동 ( Hui Dong Kim ),김혜린 ( Hyelin Kim ) 한국회계학회 2021 회계저널 Vol.30 No.4

본 연구에서는 경제 전체적인 회계이익의 분산과 회계투명성 정보를 이용하여 거시경제지표를 예측할 수 있는지 분석한다. 해외 선행연구에서는 이익분산과 동기간 실업률간의 양(+)의 관계를 이익분산이 노동자들이 이직하는 과정에서 나타나는 일시적인 마찰적 실업을 반영하기 때문으로 해석하였다. 본 연구에서는 회계투명성이 이러한 이익분산과 실업률간의 관계에 미치는 조절효과와 실업률에 미치는 직접효과를 검토하는 데 초점을 둔다. 2005년 2분기부터 2019년 3분기까지 국내 상장기업의 회계정보와 거시경제지표를 이용하여 분석한 결과는 다음과 같다. 첫째, 이익분산이 다음 분기 실업률과 유의한 양(+)의 관계를 보이지만, 동기간 실업률과는 유의한 관계가 없는 것으로 나타났다. 이는 국내에서 이익분산이 동기간보다는 다음 분기의 마찰적 실업에 주된 영향을 미치는 것을 시사한다. 둘째, 경제 전체적으로 대형회계법인의 감사를 받는 기업의 비중이 높고 비재량적 발생액의 절대 값이 적을수록 당기와 차기의 실업률이 감소하는 것으로 나타났다. 이는 회계투명성이 높을 수록 실업률이 감소함을 의미한다. 셋째, 이익분산과 다음 분기 실업률간의 유의한 양(+)의 관계가 대형회계법인에서 감사를 받는 기업의 비중이 높을수록 약해지는 것으로 나타났다. 이는 회계투명성이 높을수록 이익분산과 차기 실업률간의 양(+)의 관계를 약화시키는 음(-)의 조절효과를 의미한다. 넷째, 국내에서 이익분산은 동기간 실질 국내총생산 성장률과 음(-)의 관계가 있으며, 대형회계법인에서 감사를 받는 기업의 비중이 높을수록 이러한 관계가 약화된다. 이는 회계투명성이 이익분산과 경제성장률간의 음(-)의 관계를 줄여주는 양(+)의 조절효과를 의미한다. 본 연구는 회계투명성과 거시경제지표간의 관계를 분석함으로써 회계투명성의 경제적 효과에 대한 선행연구에 기여한다. 또한 국내에서 신외감법 시행 등의 회계제도 개혁이 지속적으로 이어지기 위해 필요한 회계투명성과 거시경제지표간의 관계에 대한 국민적 공감대 형성에도 기여할 것으로 기대된다. This paper examines whether information about earnings dispersion and accounting transparency can be used to improve predictability of macroeconomic indicators. Using Korean data for 2005:Q2-2019:Q3, we find the following results. First, earnings dispersion is positively associated with one-quarter-ahead unemployment rates, but not with current unemployment rates. Second, unemployment is reduced when more firms in the economy are audited by Big4 accounting firms and the whole-economy median of absolute discretionary accruals is lower. That is, accounting transparency is negatively associated with unemployment rates. Third, the positive association between earnings dispersion and one-quarter-ahead unemployment is weaker as more firms in the economy are audited by Big4. This suggests a negative moderating effect of accounting transparency on the association between earnings dispersion and unemployment. Finally, earnings dispersion is negatively associated with current real gross domestic product (GDP) growth, and this association is attenuated when more firms are audited by Big4. This suggests a positive moderating effect of accounting transparency on the association between earnings dispersion and real GDP growth. This study contributes to the large literature on economic consequences of accounting transparency by showing the effects of transparency on macroeconomic indicators, such as unemployment and GDP growth.

택시 데이터 분석을 통한 수요 예측과 승차대 위치 개선

김예원(Yewon Kim),김유정(Yujung Kim),김주아(JuA Kim),이유정(YooJung Lee),이우기(Wookey Lee),이수안(Suan Lee) 한국정보과학회 2021 한국정보과학회 학술발표논문집 Vol.2021 No.12

Antiviral Activity of Plant-derived Natural Products against Influenza Viruses

Seonjeong Kim(김선정),Yewon Kim(김예원),Ju Won Kim(김주원),Yu-bin Hwang(황유빈),Seong Hyeon Kim(김성현),Yo Han Jang(장요한) 한국생명과학회 2022 생명과학회지 Vol.32 No.5

인수공통 호흡기바이러스인 인플루엔자바이러스 감염으로 인해 공중보건과 가축산업에 심각한 피해가 지속적으로 발생하고 있다. 인플루엔자 백신 접종을 통해 항원형이 일치하는 바이러스 감염에 대해 우수한 방어면역을 제공하고 있으나, 효과적인 바이러스 감염 제어에는 여전히 큰 공백이 존재하고 있다. 다양한 항원형을 갖는 바이러스에 동시방어가 가능한 범용인플루엔자백신 개발과 함께 바이러스 치료효과를 제공하는 항바이러스제의 개발도 중요한 접근법으로 고려되고 있다. 현재 널리 사용되고 있는 인플루엔자 항바이러스제의 불완전한 치료효과와 내성바이러스의 출현 등의 문제들로 인해 식물 유래 천연물의 항바이러스 활성에 대한 관심이 증가하고 있다. 특히, 현재 진행 중인 코로나-19 팬데믹은 범용적인 항바이러스 활성을 갖는 안전하고 효과적인 항바이러스제 개발의 필요성을 뚜렷이 보여준다. 본 리뷰는 현재까지 보고된 천연물의 항인플루엔자바이러스 활성을 요약하였다. 또한, 항바이러스 활성을 갖는 천연물의 바이러스 사멸활성과 면역증강활성을 이용하는 신규 백신개발과 면역증강제 개발 가능성에 대해서도 분석하였다. Influenza viruses are zoonotic respiratory pathogens, and influenza infections have caused a substantial burden on public health systems and the livestock industry. Although currently approved seasonal influenza vaccines have shown potent protection efficacy against antigenically well-matched strains, there are considerable unmet needs for the efficient control of viral infections. Enormous efforts have been made to develop broadly protective universal influenza vaccines to tackle the huge levels of genetic diversity and variability of influenza viruses. In addition, antiviral drugs have been considered important interventions for the treatment of viral infections. The viral neuraminidase inhibitor oseltamivir is the most widely used antiviral medication to treat influenza A and influenza B viruses. However, unsatisfactory clinical outcomes resulting from side effects and the emergence of resistant variants have led to greater attention being paid to plants as a natural resource for anti-influenza drugs. In particular, the recent COVID-19 pandemic has underpinned the need for safe and effective antiviral drugs with a broad spectrum of antiviral activity to prevent the rapid spread of viruses among humans. This review outlines the results of the antiviral activities of various natural products isolated from plants against influenza viruses. Special focus is paid to the virucidal effects and the immune-enhancing effects of antiviral natural products, since the products have broad applications as inactivating agents for the preparation of inactivated vaccines and vaccine adjuvants.

X-ray Induced Luminescence Properties of Polystyrene, Gd2O2S:Tb and CsI:TI Scintillators

Wooseub Kim,Myungsoo Kim,Yewon Kim,Jinhwan Kim,Jisung Hwang,Kilyoung Ko,Minjoo Lee,Gyuseong Cho 대한방사선방어학회 2019 대한방사선방어학회 학술발표회 논문요약집 Vol.2019 No.04

Evaluation of food effects on the pharmacokinetics of Pelargonium sidoides and Coptis with each bioactive compound berberine and epicatechin after a single oral dose of an expectorant and antitussive agent UI026 in healthy subjects

Yewon Park,WonTae Jung,양은솔,Kyu-Yeol Nam,Woo-Ri Bong,Jaehee Kim,Kyu Yeon Kim,SeungHwan Lee,Joo-Youn Cho,Jang-Hee Hong,JaeWoo Kim 대한임상약리학회 2022 Translational and Clinical Pharmacology Vol.30 No.1

UI026 is an expectorant and antitussive agent which is a new combination of Pelargonium sidoides extract and Coptis extract. The bioactive compounds of Pelargonium sidoides and Coptisextracts were identified as epicatechin and berberine, respectively. This study evaluated the effect of food on the pharmacokinetics (PKs) and safety of UI026. A randomized, openlabel, single-dose, 2-treatment, parallel study in 12 healthy male subjects was performed. Subjects received a single oral dose of UI026 (27 mL of syrup) under a fed or fasted condition according to their randomly assigned treatment. Blood samples for the PK analysis were obtained up to 24 hours post-dose for berberine and 12 hours post-dose for epicatechin. The PK parameters were calculated by non-compartmental analysis. In the fed condition, the mean maximum plasma concentration (C max ) and mean area under the plasma concentrationtime curve from time zero to the last observed time point (AUC last ) for berberine were approximately 33% and 67% lower, respectively, compared with the fasted condition, both showing statistically significant difference. For epicatechin, the mean C max and mean AUC lastwere about 29% and 45% lower, respectively, compared to the fasting condition, neither of which showed a statistically significant difference. There were no drug-related adverse events. This finding suggests that food affects the systemic exposure and bioavailability of berberine and epicatechin.

A study on back irradiation flat panel detector with crystal silicon based x-ray CMOS image sensor

Kim, Myung Soo,Kim, Yewon,Lim, Kyung Taek,Kang, Donguk,Cho, Gyuseong Pergamon 2019 Radiation physics and chemistry Vol.155 No.-

<P><B>Abstract</B></P> <P>In order to find an image of small-sized defects in a subject that consists of a high Z-number material, the X-ray image sensor should have a high spatial and a high radiometric resolutions for the high energy X-ray imaging. Because the sensors based on thin film transistors cannot make small size pixels, the sensors based on CMOS technology have been considered. Moreover, in order to overcome the degradation of the spatial resolution with a thick scintillator, the back irradiation (BI) method was proposed. In this study, we verified the combination of the BI method and the sensor based on the CMOS technology. From the results of the light yield, which is related to the radiometric resolution, the thin wafer is one of the important factors for enhancing the collection efficiency of the BI method, especially in the collection of the soft X-ray. In addition, the high voltage on the tube helps improve the efficiency of the BI method. From the results of the modulation transfer function, which is related to the spatial resolution, the BI method has a better result compared with the conventional method, which is called front irradiation, no matter the thickness of the scintillators.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The back irradiation method with CMOS X-ray image sensor was designed and tested. </LI> <LI> The light yield might be increased when the thin silicon wafer is used. </LI> <LI> The MTF is increased 38% with thick scintillator. </LI> </UL> </P>

Influences of product salinity on the retronasal threshold values of nine kokumi peptides isolated from soybean fermented food

Yewon Kim,Yejin Shin,Tackhyun Park,Mina K. Kim 한국식품영양과학회 2022 한국식품영양과학회 학술대회발표집 Vol.2022 No.10

Wave Chandelier

Yewon Kim(김예원) 한국디자인학회 2023 한국디자인학회 국제초대전도록 Vol.2023 No.12

Utilization of Preventive Therapy in Korean Migraine Patients

Yewon Kim,Susin Park,Eonjeong Kim,Nam Kyung Je 한국임상약학회 2021 한국임상약학회지 Vol.31 No.1

Background: Migraine is a common neurological disorder that affects the quality of life and causes several health problems. Preventive migraine treatment can reduce migraine frequency, headache severity, and health care costs. This study aimed to estimate the utilization of migraine preventive therapy and associated factors in eligible patients. Methods: We studied 534 patients with migraine who were eligible for migraine preventive therapy using 2017 National Patient Sample (NPS) data from the Health Insurance Review and Assessment Service (HIRA). We estimated the migraine days by calculating the monthly average number of defined daily dose (DDD) of migraine-specific acute drug. Patients with a monthly average number of DDD of 4 or more were considered as subjects for preventive treatment. Chi-square test and multiple logistic regression analysis were used to determine the association between the preventive therapy and the influencing variables. Results: Less than half of the eligible patients for prophylaxis (n=234, 43.8%) were prescribed preventive therapy. Multiple logistic regression results show that migraine preventive therapy was influenced by age, the type of migraine, and some comorbidities. Patients over the age of 50 tend to receive less prophylactic treatment than under the age of 40. On the other hand, migraine patients with epilepsy or depression were more likely to receive preventive therapy. Sumatriptan was the most preferred medication for acute treatment, and propranolol was the most commonly prescribed drug for prevention. Conclusions: More than half of the patients who were candidates for migraine prophylaxis were not receiving suitable preventive treatment. Positive factors affecting the use of migraine prevention were the presence of comorbidities such as epilepsy and depression.