• Journal of Positioning, Navigation, and Timing
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• 제9권4호
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• pp.397-403
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• 2020

In order to synchronize a remote system time to the reference time like Coordinated Universal Time (UTC), it is required to compare the time difference between the two clocks. The time comparison data may have some outliers and the time synchronization performance can be significantly degraded if the outliers are not removed. Therefore, it is required to employ an effective outlier detection algorithm for keeping high accurate system time. In this paper, an outlier detection method is presented for the time difference data of GNSS time transfer receivers. The time difference data between the system time and the GNSS usually have slopes because the remote system clock is under free running until synchronized to the reference clock time. For investigating the outlier detection performance of the proposed algorithm, simulations are performed by using the time difference data of a GNSS time transfer receiver corrected to a free running Cesium clock with intentionally inserted outliers. From the simulation, it is investigated that the proposed algorithm can effectively detect the inserted outliers while conventional methods such as modified Z-score and adjusted boxplot cannot. Furthermore, it is also observed that the synchronization performance can be degraded to more than 15% with 20 outliers compared to that of original data without outliers.

• 산업융합연구
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• 제20권6호
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• pp.55-63
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• 2022

본 연구의 목적은 인지기능저하 대상자를 돌보는 요양병원 간호사의 공감역량이 의사소통행위에 미치는 영향을 파악하고 그 과정에서 회복탄력성의 매개효과를 검정하는데 있다. 자료수집 기간은 2021년 9월27일부터 10월 22일까지이며, P시에 재직 중인 요양병원 간호사 131명을 대상으로 하였다. 수집된 자료는 SPSS WIN 25.0을 이용하여 기술통계, 상관관계, 단계별회귀분석으로 분석하였다. 연구결과 첫째, 공감역량과 의사소통(r=.625, p<.001), 회복탄력성과 의사소통행위(r=.535, p<.001)간 에는 유의한 정(+)적 상관관계가 있음을 확인하였다. 둘째, 공감역량은 의사소통행위(𝛽=.725, p<.001)에 유의한 영향을 주며, 그 과정에서 회복탄력성이 부분매개효과(Z=2.012, p=.042)가 있는 것으로 나타났다. 따라서 인지기능저하 대상자를 돌보는 요양병원 간호사의 의사소통행위를 향상시키기 위해서는 공감역량과 회복탄력성를 증진시킬 수 있는 프로그램을 개발하고 적용할 것을 제안한다.

• Structural Engineering and Mechanics
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• 제84권1호
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• pp.17-33
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• 2022

An experimental study is carried out to investigate the performance of the cutting tool regarding the insert wear, surface roughness, cutting forces, cutting power and material removal rate of three coated carbides GC2015 (TiCN-Al₂O₃-TiN), GC4215 (Al₂O₃-Ti(C,N)) and GC1015 (TiN) during the dry turning of AISI4140 steel. For this purpose, a Taguchi design (L₉) was adopted for the planning of the experiments, the effects of cutting parameters on the surface roughness (R_a), tangential cutting force (F_z), the cutting power (P_c) and the material removal rate (MRR) were studied using analysis of variance (ANOVA), the response surface methodology (RSM) was used for mathematical modeling, with which linear mathematical models were developed for forecasting of R_a, F_z, P_c and MRR as a function of cutting parameters (V_c, f, and a_p). Then, Multi-Objective Ant Lion Optimizer (MOALO) has been implemented for multi-objective optimization which allows manufacturers to enhance the production performances of the machined parts. Furthermore, in order to characterize and quantify the flank wear of the tested tools, some machining experiments were performed for 5 minutes of turning under a depth of 0.5 mm, a feed rate of 0.08 mm/rev, and a cutting speed of 350 m/min. The wear results led to a ratio (V_B-GC4215/V_B-GC2015) of 2.03 and (V_B-GC1015/V_B-GC2015) of 4.43, thus demonstrating the efficiency of the cutting insert GC2015. Moreover, SEM analysis shows the main wear mechanisms represented by abrasion, adhesion and chipping.

• 한국미생물·생명공학회지
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• 제16권5호
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• pp.402-406
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• 1988

발효생산된 에탄올의 농도가 Zymomonas mobilis 에서 당대사에 관련된 효소의 역가에 미치는 영향을 조사하였다. 그 결과, glucose kinase 및 glucose 6-phosphate dehydrogenase는 큰 영향을 받지 않았으나 transketolase 역가는 에탄을 농도가 증가함에 따라 심하게 저해됨을 알았다. 따라서 에탄을 농도의 증가에 따른 균성장속도의 감소는 transketolase에 의하여 영향을 받는 것으로 생각되었다.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2613-2620
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• 2023

Excellent thermal neutron absorption performance of boron expands the potential use of boron rich slag to prepare epoxy resin matrix nuclear shielding composites. However, shielding attenuation behaviors and mechanism of the composites against gamma rays are unclear. Based on the radiation protection theory, Phy-X/PSD, XCOM, and ⁶⁰Co gamma ray source were integrated to obtain the shielding parameters of boron rich slag/epoxy resin composites at 0.015-15 MeV, which include mass attenuation coefficient (µ_t), linear attenuation coefficient (µ), half value thickness layer (HVL), electron density (N_eff), effective atomic number (Z_eff), exposure buildup factor (EBF) and exposure absorption buildup factor (EABF).µ_t, µ, HVL, N_eff, Z_eff, EBF and EABF are 0.02-7 cm²/g, 0.04-17 cm^-1, 0.045-20 cm, 5-14, 3 × 10²³-8 × 10²³ electron/g, 0-2000, and 0-3500. Shielding performance is BS4, BS3, BS3, BS1 in descending order, but worse than ordinary concrete. µ and HVL of BS1-BS4 for ⁶⁰Co gamma ray is 0.095-0.110 cm^-1 and 6.3-7.2 cm. Shielding mechanism is main interactions for attenuation gamma ray by BS1-BS4 are elements with higher content or higher atomic number via Photoelectric Absorption at low energy range, and elements with higher content via Compton Scattering and Pair Production in Nuclear Field at middle and higher energy range.

• 분석과학
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• 제21권6호
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• pp.502-509
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• 2008

혈청 내 콜레스테롤을 정량분석하기 위한 일차분석법으로 동위원소희석 액체크로마토그래피/질량분석법(isotope dilution liquid chromatography/mass spectrometry)을 사용하였다. 콜레스테롤은 Thermo ODS hypersil $C^{18}$ 칼럼을 사용하여 분리하였고, 이동상은 100% 메탄올, 유속은 0.3 mL/min으로 하였다. 콜레스테롤과 콜레스테롤-$3,4-13C_2$는 $[M-H_2O+H]^+$이온에 해당하는 m/z 369.4와 371.3에서 모니터링하여 정량에 합당한 크로마토그램을 얻을 수 있었다. 방법의 유효성을 증명하기 위해서 NIST SRM 909b를 분석한 결과 인증값과 불확도 범위 내에서 일치하는 것을 확인하였다. 이 방법을 바탕으로 혈청 인증표준 물질 4 종류를 제조하여 인증을 실시하였다. 인증 결과, 반복성의 상대표준오차는 0.1~0.8%, 재현성의 경우 0.24%이하, 확장 불확도는 95% 신뢰도구간에서 약 1.43%로 나타났다.

• 한국응용과학기술학회지
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• 제40권5호
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• pp.1055-1064
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• 2023

본 연구는 간호대학생의 건강관심도와 건강증진행위와의 관계에서 건강관리 자기효능감의 매개효과를 규명하기 위해 시행되었다. 연구 대상자는 G시와 J도에 소재한 4개 대학교의 간호학과 재학생 255명이다. 수집된 자료는 SPSS 25.0프로그램을 이용하여 기술통계와 t-test, ANOVA, Pearson correlation, 회귀분석을 시행하였으며 매개효과 검증을 위해 Sobel test를 실시하였다. 연구결과, 건강관리 자기효능감은 건강관심도와 건강증진행위 사이에서 부분매개효과를 나타냈고(Z=5.54, p<.001), 건강관심도와(β=.20, p<.001) 건강관리 자기효능감이(β=.39, p<.001) 높을수록 건강증진행위 수준이 높아지며, 건강증진행위를 설명하는 설명력(R2)은 48%이었다. 따라서 간호대학생의 건강증진행위를 향상시키기 위해서는 건강관심도를 높일 뿐만 아니라 건강관리 자기효능감을 동시에 강화시킬 수 있는 효과적인 전략 마련이 필요하다.

• Nuclear Engineering and Technology
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• 제55권10호
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• pp.3815-3821
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• 2023

Dosimetric studies in Nuclear Medicine are very important, especially with new therapeutic methods, the number of which has increased significantly with the Theranostic approach (determining diagnostic-therapeutic pairs where similar molecules are labelled with different isotopes in order to diagnose and treat malignant diseases). Peptide receptor radionuclide therapy (PRRT) has been used successfully for many years to treat neuroendocrine tumors (NET). ⁹⁰Y-DOTATOC is one of the radiopharmaceuticals used frequently in this type of therapy. In this work, blood and urine samples from 13 patients treated with ⁹⁰Y-DOTATOC were measured by a liquid scintillation beta counter (LSC). Calibration of the beta counter for this type of measurement was done and all results are presented in the paper. The presented paper also provides a methodology for determining the measurement uncertainty for this type of measurement. Immediately after the administration of radiopharmaceuticals, the activity in the blood was different from 6.31% to 88.9% of the applied radioactivity, while 3 h after the termination of the application, the average value of radiopharmaceuticals in the blood was only 3.84%. The activity in the excreted urine depended on the time when the patients urinated after the therapy. It was measured that as much as 58% of the applied radioactivity was excreted in the first urine after the therapy in a patient who urinated 4.5 h after the completed application of the therapy. In most patients, the highest urine activity was in the first 10 h after the application, while the activities after that time were negligibly low. The described methodology of measuring and evaluating activity in blood and excreted urine can be applied to other radiopharmaceuticals used in nuclear medicine. It could be useful for researchers for dosimetric assessments in clinical application of PRRT.

• 한국응용과학기술학회지
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• 제41권1호
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• pp.128-137
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• 2024

본 연구는 간호대학생을 대상으로 강점인식과 진로관여행동과의 관계에서 진로적응성의 매개효과를 확인하고자 수행되었다. 연구대상은 G광역시와 J도에 소재한 대학교 3곳의 간호대학생 284명을 대상으로 하였다. 자료는 기술통계, t-test, ANOVA, Pearson 상관분석 및 Baron과 Kenny의 3단계 매개 회귀분석을 이용하였고, Sobel test로 검증하였다. 강점인식과 진로관여행동사이에서 진로적응성은 부분매개효과를 나타냈으며(Z=6.66, p<.001), 강점인식 수준이 높을수록(β=.24, p<.001), 진로적응성이 높을수록(β=.49, p<.001), 진로관여행동 수준이 높아지며, 진로관여행동을 설명하는 설명력은 47%이었다. 간호대학생의 진로관여행동 수준의 향상을 위해서는 진로적응력 함양을 위한 구체적인 행동전략과 더불어 진로교육 및 상담을 통해 개인의 강점을 인지할 수 있는 지도전략이 필요하다.

• Parasites, Hosts and Diseases
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• 제62권1호
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• pp.1-29
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• 2024

This article analyzed the infection characteristics of metacercariae of Metagonimus spp. (MsMc) in fish from 9 major water systems in Korea. A total of 19,568 fish in 87 species were examined over a period of 10 years (2011-2020). MsMc were detected in fish from all 44 survey areas in 9 water systems. Most of the surveyed sites showed very low and low infection levels (66.7%), while 33.3% of the areas, such as Tamjin-gang and Seomjin-gang, revealed moderate and high infection levels. High endemicity depends on the abundance of susceptible fish species, especially sweet smelt (Plecoglosus altivelis). The susceptibility index (SI) with MsMc in index fish, Zacco spp., was very low and low levels in 62.0%, moderate in 28.0%, and high in 10.0% regions. The SI was highest in the following order: Yeongam-cheon (283.8), Hoeng-cheon (192.3), Togyo-jeosuji (131.2), Deokcheon-gang (119.1), and Joyang-gang (106.3). The recent infection status of MsMc in P. altivelis was analyzed by the survey localities. In addition, except for P. altivelis, 9 fish species were highly infected with MsMc in some survey areas, including Zacco platypus, Z. koreanus, Z. temminckii, Opsariichthys uncirostris, Rhynchocypris oxycephalus, Carassius auratus, Acheilognathus rhombeus, Onchorhynchus masou, and Tribolodon hakonensis. In Korea, 74 fish species (15 families) are collectively listed as second intermediate hosts of Metagonimus spp. This review provides several novel characteristics of MsMc infection and clarifies the fish species of second intermediate host of Metagonimus spp. in this country.