• 한국항공우주학회지
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• 제50권2호
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• pp.93-101
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• 2022

실속, 결빙, 센서 이상 등으로 인해 일어나는 제어불능 또는 비정상 비행 상황은 항공기의 추락으로 이어지기 때문에 필수적으로 대비해야 한다. 이와 관련해 비정상 비행 상황에서 항공기의 동적 특성을 정확하게 파악하는 것은 매우 중요하다. 본 논문에서는 일시적인 센서 이상이 발생한 고받음각의 비정상 비행상태 항공기에 대해서 기존의 칼만 필터 기반의 시스템 식별법 대비 보다 효과적인 적응 차수 조노토픽 칼만 필터와 이동창-최소자승법을 활용한 시스템 식별법을 제시하였다. 제안한 방법을 실제 비행 데이터에 적용하고 그 성능을 기존 연구 결과와 비교하였다.

• 한국환경복원기술학회지
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• 제25권5호
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• pp.29-41
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• 2022

Alien species cause problems in various ecosystems, reduce biodiversity, and destroy ecosystems. Due to these problems, the problem of a management plan is increasing, and it is difficult to accurately identify each individual and calculate the number of individuals, especially when researching alien turtle species such as GPS and PIT based on capture. this study intends to conduct an individual recognition study using a UAV. Recently, UAVs can take various sensor-based photos and easily obtain high-definition image data at low altitudes. Therefore, based on previous studies, this study investigated five variables to be considered in UAV flights and produced a test paper using them. OCR was used to monitor the displayed turtles using the manufactured test paper, and this confirmed the recognition rate. As a result, the use of yellow numbers showed the highest recognition rate. In addition, the minimum threat distance was confirmed to be 3 to 6m, and turtles with a shell size of 6 to 8cm were also identified during the flight. Therefore, we tried to propose an object recognition methodology for turtle display text using OCR, and it is expected to be used as a new turtle monitoring technique.

• 한국컴퓨터정보학회논문지
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• 제27권2호
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• pp.203-212
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• 2022

본 연구의 목적은 대학신입생의 학교 및 학과선택 요인과 만족도를 파악하기 위함이다. G시에 위치한 K대학의 2021년 신입생 499명을 대상으로 대학신입생의 학교 및 학과선택 요인과 만족도를 파악하고 SPSS WIN 18.0 Program으로 분석하였다. 연구결과 대학선택요인으로 대학정보매체는 인터넷/SNS, 대학정보제공자는 학교선생님, 대학등록에 영향요인은 취업률, 등록결정은 본인으로 나타났다. 대학만족도는 3.43점이고 성별(t=5.527, p=.019)과 입학전형(F=5.527, p<.001)에서 유의한 차이를 나타내었다. 학과만족도는 3.86점이고 입학전형(F=3.004, p=.018)에서 유의한 차이를 나타내었다. 학교만족도와 학과만족도는 유의한 양의 상관관계를 나타내었다(r=5.527, p<.001). 대학은 객관적이고 체계적인 대학 정보제공을 통해 학생들을 만족시키고 대학경쟁력을 향상시킬 수 있다.

• Mycobiology
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• 제50권5호
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• pp.366-373
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• 2022

Regulation of proper gene expression is important for cellular and organismal survival, maintenance, and growth. Abnormal gene expression, even for a single critical gene, can thwart cellular integrity and normal physiology to cause diseases, aging, and death. Therefore, gene expression profiling serves as a powerful tool to understand the pathology of diseases and to cure them. In this study, the difference in gene expression in Flammulina velutipes was compared between the wild type (WT) mushroom and the mutant one with clogging phenomenon. Differentially expressed transcripts were screened to identify the candidate genes responsible for the mutant phenotype using the DNA microarray analysis. A total of 88 genes including 60 upregulated and 28 downregulated genes were validated using the real-time quantitative PCR analysis. In addition, proteomic differences between the WT and mutant mushroom were analyzed using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF). Interestingly, the genes identified by these genomic and proteomic analyses were involved in stress response, translation, and energy/sugar metabolism, including HSP70, elongation factor 2, and pyruvate kinase. Together, our data suggest that the aberrant expression of these genes attributes to the mutant clogging phenotype. We propose that these genes can be targeted to foster normal growth in F. velutipes.

• Asia Marketing Journal
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• 제20권3호
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• pp.83-103
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• 2018

The purpose of this research is to investigate the effect of customer-contact employees support on service recovery efforts. Service companies should try to prevent the service failure situation from occurring, but it is realistic that the service failure occurs due to the characteristics of the service. Service recovery efforts of service providers are important because effective responses to service failures can enhance customer satisfaction despite service failures. Social support for customer-contact employees needs to improve service recovery efforts. Specifically, this study focuses on the mediation roles of job burnout and customer orientation in relationship between social support for customer-contact employees and service recovery efforts. Social exchange theory was used as the theoretical underpinning of the research model. Based on reciprocity principle, this paper suppose that support for customer-contact employees and service recovery effort are a kind of social exchange relationship. Social supports for customer-contact employees are categorized into internal and external organization. Internal organization is POS(perceived organizational support) and external organization is customer support. The research model was tested with the data gathered from the flight attendants whose emotional labor intensity was relatively high and the service failure frequently occurred. As a result of analysis, social supports for customer-contact employees classified into organizational support, supervisor support, and customer support are found to have differential impacts on job burnout and customer orientation. It has been found that job burnout of service providers is negatively affecting service recovery efforts. On the other hand, customer orientation of service providers has a positive influence on service recovery efforts. Based on the results of the analysis, we provide practical implications for effective service recovery efforts in service failure situations, and suggest the theoretical implications to explain the process of service recovery effort. Finally, limitations of the study and directions for future research are suggested.

• 한국군사과학기술학회지
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• 제26권1호
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• pp.1-9
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• 2023

The skin structure of sensor pod mounted on the exterior of aircraft can be exposed to the acoustic dynamic load and static load such as aerodynamic pressure and inertial load during flight. Fatigue life prediction of structural model under acoustic load should be performed and also differential stiffness of model modified by static load should be considered. The acoustic noise test spectrum of MIL-STD-810G was applied to the structural model and the stress response power spectral density (PSD) was calculated. The frequency response analysis was performed with or without prestress induced by inplane static load, and the response spectrum was compared. Time series data was generated using the calculated PSD, and the time and frequency domain fatigue life were predicted and compared. The variation of stress response spectrum due to static load and predicted fatigue life according to the different structural model considering mean stress were examined and decreasing fatigue life was observed in the model with prestress of compressive static load.

• 예술인문사회 융합 멀티미디어 논문지
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• 제6권8호
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• pp.577-584
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• 2016

무인항공기는 조종사 없이 자율적으로 비행하는 동력 비행체를 이야기한다. 최근 무인항공기는 동영상 촬영, 항공사진측량 등 다양한 분야에 적용이 되고 있으며 특히 공간정보 관련 분야에서 무인항공 사진측량 기술은 자료 취득의 신속성과 경제성 때문에 많은 주목을 받고 있다. 하지만 무인항공측량 기술에 대한 분석적인 연구는 부족한 실정이다. 본 연구에서는 무인항공측량을 위한 장비에 대한 조사를 수행하고 지형모델 및 정사영상을 효과적으로 생성하기 위한 무인항공측량 기술과 트랜드 분석을 수행하였다. 연구를 통해 회전익 및 고정익 무인항공기의 특징 및 활용분야를 파악하였다. 또한 무인항공측량의 공정에서 새로운 측량방법을 적용하여 개선할 수 있는 방법을 제시하였다. 향후 지형모델 및 정사영상 제작을 위한 무인항공측량에 대한 분석적인 연구가 이루어진다면 공간정보 관련 산업의 효율성이 크게 증대될 것으로 기대된다.

• 한국항공운항학회지
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• 제31권2호
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• pp.81-88
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• 2023

SHM (Structural Health Monitoring) technique for monitoring aircraft structural health and damage, EHM (Engine Health Monitoring) for monitoring aircraft engine performance, and APM (Application Performance Management) is used for each function. APMS (Airplane Performance Monitoring System) is a program that comprehensively applies these techniques to identify the difference between the performance manual provided by the manufacturer and the actual fuel mileage of the aircraft and reflect it in the flight plan. The main purpose of using APMS is to understand the performance of each aircraft, to plan and execute flights in an optimal way, and consequently to reduce fuel consumption. First, it is to check the fuel efficiency trend of each aircraft, check the correlation between the maintenance work performed and the fuel mileage, find the cause of the fuel mileage increase/decrease, and take appropriate measures in response. Second, it is to find the cause of fuel mileage degradation in detail by checking the trends by engine performance and fuselage drag effect. Third, the APMS is to be used in making maintenance work decisions. Through APMS, aircraft with below average fuel mileage are identified, the cause of fuel mileage degradation is identified, and appropriate corrective actions are determined. Fourth, APMS data is used to analyze the economic analysis of equipment installation investment. The cost can be easily calculated as the equipment installation cost, but the benefit is fuel efficiency improvement, and the only way to check this is the manufacturer's theory. Therefore, verifying the effect after installation and verifying the economic analysis is to secure the appropriateness of the investment. Through this, proper investment in fuel efficiency improvement equipment will be made, and fuel efficiency will be improved.

• 한국항행학회논문지
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• 제26권6호
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• pp.441-447
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• 2022

본 논문에서는 주파수 오차 및 위상 오차가 존재하는 텔레메트리 시스템에 적용하기 위한 FLL-assisted-PLL 기반의 시각 동기 알고리즘을 제안한다. 텔레메트리 시스템은 분산 획득 장치들로부터 상태 정보를 계측하여 비행 상태를 분석할 수 있는 데이터를 생성하며, 각 상태 정보를 오차 없이 수집하기 위해서는 마스터와 슬레이브간의 정밀한 시각 동기가 필요하다. 이때, 마스터의 시각펄스에는 외부 및 내부 요소로 인하여 발생할 수 있는 주파수 및 위상 변화가 존재하므로 지속적으로 텔레메트리 데이터를 제공하기 위해서 정밀 시각 동기를 유지할 수 있는 방법이 반드시 필요하다. 본 논문에서는 고속 시각동기가 가능할 뿐만 아니라 넓은 범용성, 높은 시각 동기 정밀도를 갖는 FLL-assisted-PLL 기반의 시각 동기 알고리즘을 제안하고 구현을 통해 타당성을 검증하였다. 이때 이론적인 성능 검증을 위하여 파이썬 기반의 시뮬레이션을 수행하였으며, 실제 텔레메트리 시스템에 적용하기 위해 FPGA 내에 VHDL 로직을 구현하여 주파수 오차 및 위상 오차에 따른 성능 평가를 수행하였다.

• Mycobiology
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• 제51권5호
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• pp.360-371
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• 2023

Hispidin is an important styrylpyrone produced by Sanghuangporus sanghuang. To analyze hispidin biosynthesis in S. sanghuang, the transcriptomes of hispidin-producing and non-producing S. sanghuang were determined by Illumina sequencing. Five PKSs were identified using genome annotation. Comparative analysis with the reference transcriptome showed that two PKSs (ShPKS3 and ShPKS4) had low expression levels in four types of media. The gene expression pattern of only ShPKS1 was consistent with the yield variation of hispidin. The combined analyses of gene expression with qPCR and hispidin detection by liquid chromatography-mass spectrometry coupled with ion-trap and time-of-flight technologies (LCMS-IT-TOF) showed that ShPKS1 was involved in hispidin biosynthesis in S. sanghuang. ShPKS1 is a partially reducing PKS gene with extra AMP and ACP domains before the KS domain. The domain architecture of ShPKS1 was AMP-ACP-KS-AT-DH-KR-ACP-ACP. Phylogenetic analysis shows that ShPKS1 and other PKS genes from Hymenochaetaceae form a unique monophyletic clade closely related to the clade containing Agaricales hispidin synthase. Taken together, our data indicate that ShPKS1 is a novel PKS of S. sanghuang involved in hispidin biosynthesis.