• 한국위성정보통신학회논문지
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• 제9권4호
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• pp.42-46
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• 2014

본 논문에서는 1.55GHz에서 1.81GHz 대역을 사용하는 GNSS(Global-Navigation Satellite Service)시스템에, 단말기의 전원안정화를 위해서 PCB(Printed Circuit Board) 내층에 삽입될 코일 구조의 EBG(Electromagnetic Band Gap) 구조체를 제안 및 제작한다. 제작한 EBG 구조체의 테스트 결과, 사용 주파수 대역에서 삽입손실(S21)이 약 -50dB 이하로 측정되었다. 본 연구결과는 향후, PCB 회로 설계의 PDN(Power Delivery Network)구조의 안정화 향상 및 EMI(Electro Magnetic Interference) 대책에 효과적일 것으로 기대된다.

• The Plant Pathology Journal
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• 제27권1호
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• pp.53-58
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• 2011

Systemic acquired resistance is a form of inducible resistance that is triggered in systemic healthy tissues of local-infected plants. Several candidate signaling molecules emerged in the past two years, including the methylated derivatives of well-known defense hormones salicylic acid (SA) and jasmonic acid (JA). In our present study, the symptom on Cucumber mosaic virus (CMV) infected Arabidopsis leaves in 0.1 mM SA or 0.06 mM JA pre-treated plants was lighter (less reactive oxygen species accumulation and less oxidative damages) than that of the control group. JA followed by SA (JA${\rightarrow}$SA) had the highest inhibitory efficiency to CMV replication, higher than JA and SA simultaneous co-pretreatment (JA+SA), and higher than a JA or a SA single pretreatment. The crosstalk between the two hormones was further investigated at the transcriptional levels of pathogenesis-related genes. The time-course measurement showed JA might play a more important role in the interaction between JA and SA.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.141-141
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• 2000

In situ surface magneto-optic Kerr effect(SMOKE), X-ray photoelectron spectroscopy(XPS) and low energy electron diffraction(LEED) were used to study magnetic and structural properties of ultrathin Fe films grown on the Pd(111) surface. The SMOKE measurement showed strong enhancement of ferromagnetism after proper annealing process. Simultaneous changes in morphology was checked by LEED and XPS. After room temperature Fe deposition. longitudinal magnetization appeared above a critical thickness between 2.0 and 2.5 monolayers. When annealed at 450K, 2.0 monolayer Fe film exhibited boty longitudinal and polar magnetizations while 3.0 and 5.5 monolayer films showed little changes. After annealing at 600K, both magnetizations were totally destroyed in 2.0 monolayer film, but longitudinal magnetization was enhanced in 3.0 monolayer film. In the case of 5.5 monolayer film, it was only after 660K annealing that the enhancement of the longitudinal magnetization was observed. It was concluded that the surface flatness and the amount of intermixing were critical in the development of surface magnetism of this system.

• Smart Structures and Systems
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• 제15권1호
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• pp.169-189
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• 2015

Convergence difficulty and available complete measurement information have been considered as two primary challenges for the identification of large-scale engineering structures. In this paper, a time domain substructural identification approach by combining a weighted adaptive iteration (WAI) algorithm and an extended Kalman filter method with a weighted global iteration (EFK-WGI) algorithm was proposed for simultaneous identification of physical parameters of concerned substructures and unknown external excitations applied on it with limited response measurements. In the proposed approach, according to the location of the unknown dynamic loadings and the partially available structural response measurements, part of structural parameters of the concerned substructure and the unknown loadings were first identified with the WAI approach. The remaining physical parameters of the concerned substructure were then determined by EFK-WGI basing on the previously identified loadings and substructural parameters. The efficiency and accuracy of the proposed approach was demonstrated via a 20-story shear building structure and 23 degrees of freedom (DOFs) planar truss model with unknown external excitation and limited observations. Results show that the proposed approach is capable of satisfactorily identifying both the substructural parameters and unknown loading within limited iterations when both the excitation and dynamic response are partially unknown.

• 대한임베디드공학회논문지
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• 제16권3호
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• pp.107-111
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• 2021

A 3D point cloud map is an essential elements in various fields, including precise autonomous navigation system. However, generating a 3D point cloud map using a single sensor has limitations due to the price of expensive sensor. In order to solve this problem, we propose a precise 3D mapping system using low-cost sensor fusion. Generating a point cloud map requires the process of estimating the current position and attitude, and describing the surrounding environment. In this paper, we utilized a commercial visual-inertial odometry sensor to estimate the current position and attitude states. Based on the state value, the 2D LiDAR measurement values describe the surrounding environment to create a point cloud map. To analyze the performance of the proposed algorithm, we compared the performance of the proposed algorithm and the 3D LiDAR-based SLAM (simultaneous localization and mapping) algorithm. As a result, it was confirmed that a precise 3D point cloud map can be generated with the low-cost sensor fusion system proposed in this paper.

• 생약학회지
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• 제50권2호
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• pp.133-140
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• 2019

In our previous study, we found uracil, adenosine, protocatechuic acid, syringin (eleutheroside B) and scoparone (6, 7-dimethoxycoumarin) in the Oplopanax elatus Nakai Stem. High-performance liquid chromatography (HPLC) -UV was used to quality and quantify the internal marker compounds in the O. elatus extract after validation of method with linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy and precision. The specificity assessment visually confirmed that the substance was detected without the introduction of other substances. The established method showed high linearity of the calibration curve and coefficient of correlation ($R^2$) of over the 0.999. HPLC was reported as five standard compounds equivalent using the following linear equation based on the calibration curve. The accuracy of measurement was 84.34 ~ 119.74% and the relative standard deviation (RSD) value was 0.28 ~ 1.60%. In addition, our established method showed high repeatability. The RSD value was 1.10 ~ 6.81%. So, we found the amount of the internal marker compounds in the O. elatus extract. These results demonstrated that can be used to quality evaluation of the O. elatus.

• 한국전자통신학회논문지
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• 제14권4호
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• pp.637-644
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• 2019

본 논문은 일반 그래프 최적화(g2o, General Graph Optimization)를 사용하여 그래프 기반 SLAM을 구현한 결과를 기술한다. 일반 그래프 최적화는 SLAM을 노드와 엣지의 그래프를 통하여 표현한다. 노드는 시간에 따른 로봇의 위치를 나타내며, 엣지는 노드들 사이의 구속 조건을 나타낸다. 구속 조건은 센서에 의한 측정값에 의해 결정된다. 일반 그래프 최적화는 구속 조건에 의해 결정되는 성능지표를 최적화하여 SLAM 문제를 해결한다. 실현된 일반 그래프 최적화 방법을 SLAM 방법의 성능 시험용으로 공개된 실험 데이터를 사용하여 검증하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권9호
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• pp.1332-1339
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• 2019

Heat stress exerts a substantial effect on dairy production. The temperature and humidity index (THI) is widely used to assess heat stress in dairy operations. Herein, we review the effects of high temperature and humidity on body temperature, feed intake, milk production, follicle development, estrous behavior, and pregnancy in dairy cows. Analyses of the effects of THI on dairy production have shown that body temperature is an important physiological parameter in the evaluation of the health state of dairy cows. Although THI is an important environmental index and can help to infer the degree of heat stress, it does not reflect the physiological changes experienced by dairy cows undergoing heat stress. However, the simultaneous measurement of THI and physiological indexes (e.g., body temperature) would be very useful for improving dairy production. The successful development of automatic detection techniques makes it possible to combine THI with other physiological indexes (i.e., body temperature and activity), which could help us to comprehensively evaluate heat stress in dairy cows and provide important technical support to effectively prevent heat stress.

• Toxicological Research
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• 제35권2호
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• pp.161-165
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• 2019

Cysteamine has been used in cosmetics as an antioxidant, a hair straightening agent, and a hair waving agent. However, recent studies indicate that cysteamine can act as an allergen to hairdressers. The objective of this study was to develop and validate a simple and effective reversed-phase high-performance liquid chromatography (RP-HPLC) method for the measurement of cysteamine and its dimer, cystamine. Sodium 1-heptanesulfonate (NaHpSO) was used as an ion-pairing agent to improve chromatographic performance. Separation was performed on a Gemini C18 column ($250mm{\times}4.6mm$, $5{\mu}m$ particle size) using a mobile phase composed of 85:15 (v/v) 4 mM NaHpSO in 0.1% phosphoric acid:acetonitrile. UV absorbance was monitored at 215 nm. The RP-HPLC method developed in this study was validated for specificity, linearity, limit of detection, limit of quantitation, precision, accuracy, and recovery. Cysteamine and cystamine were chromatographically resolved from other reducing agents such as thioglycolic acid and cysteine. Extraction using water and chloroform resulted in the recovery for cysteamine and cystamine ranging from 100.2-102.7% and 90.6-98.7%, respectively. This validated RP-HPLC method would be useful for quality control and monitoring of cysteamine and cystamine in cosmetics.

• 한국축산식품학회지
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• 제41권5호
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• pp.816-825
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• 2021

This study aims to validate a fast method of simultaneous analysis of 365 LCamenable and 142 GC-amenable pesticides in hen eggs by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively, operating in multiple reaction monitoring (MRM) acquisition modes. The sample preparation was based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction. Key method performance parameters investigated were specificity, linearity, limit of quantification (LOQ), accuracy, precision and measurement uncertainty. The method was validated at two spiking levels (10 and 50 ㎍/kg), and good recoveries (70%-120%) and relative standard deviations (RSDs) (≤20) were achieved for 92.9% of LC-amenable and 86.6% of GC-amenable pesticide residues. The LOQs were ≤10 ㎍/kg for 94.2% of LC-amenable and 92.3% of GC-amenable pesticides. The validated method was further applied to 100 egg samples from caged hens, and none of the pesticides was quantified.