• 한국전기전자재료학회논문지
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• 제32권5호
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• pp.382-386
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• 2019

The alignment characteristics of liquid crystal (LC) molecules on a solution-derived lanthanum zinc oxide (LZO) film under ion-beam irradiation were demonstrated. Using the solution process, an LZO film was fabricated on the glass substrate and cured at $100^{\circ}C$. Afterwards, ion-beam irradiation was performed following the LC alignment method. Using this film, an LC cell was fabricated and the characteristics of the LC alignment were verified. Cross polarizing microscopy and the crystal rotation method were used to investigate the alignment state of the LC molecules on the LZO films. Furthermore, field emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to explore the effect of the ion-beam irradiation on the LZO film. Through these, it was confirmed that the ion-beam irradiation induced surface modification, which demonstrated anisotropic physical and chemical surface characteristics. Due to this, uniform LC alignment was achieved. Finally, the residual DC and anchoring energy of the LC cell based on the LZO films were measured using a capacitance-voltage curve.

• Physical Therapy Rehabilitation Science
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• 제11권4호
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• pp.446-453
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• 2022

Objective: The popularization of smartphones can lead to abnormal cervical alignment in university students. The aim of this study was to investigate the relationship among smartphone screen time, cervical alignment, and muscle function in university students. Design: Cross-sectional study. Methods: Seventy-five university students participated in the study. They completed the evaluation of cervical alignment and muscle function, such as handgrip strength, proprioception, and muscle quality (tone, stiffness, and relaxation time). All participants recorded their general characteristics and individual smartphone screen time before the evaluation. They were evaluated craniovertebral angle (CVA) using smartphone application (angle meter 360) for measuring cervical alignment. The muscle function was assessed using a digital hand-held dynamometer, dual inclinometer, and MyotonPRO device. Results: Of all participants, twenty-five university students had forward head posture (CVA<49°, 33.33%). Independent t-test revealed that there were significant differences on smartphone screen time, muscle stiffness, and muscle relaxation between the participants with and without forward head posture (p<0.05). There were significant correlations between the smartphone screen time and the CVA, muscle tone, and muscle relaxation (r=-0.493, 0.250, and -0.500, respectively). Conclusions: The results indicate that the university students with forward head posture had high smartphone screen time and muscle stiffness compared to the students without forward head posture, and smartphone screen time might be associated with cervical alignment and muscle quality.

• 산업기술연구
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• 제22권B호
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• pp.155-161
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• 2002

As the wireless communications are gradually developed, the higher frequency is demanded and the smaller the size of antenna shall be reduced by the wavelength of the operating frequency. However, the smaller the size of antenna becomes, the less the gain is obtained according to the frequency, so that a new attempt such as an array antenna has been examined to improve the characteristics. Also, for the convenience of communication, the omni-directional property is required. In this paper, two antennas system which is aligned in cross direction in tested and analyzed. The main scope is focused to get an appropriated distance between the two small antennas to get better properties. There are various ways of array arrangement, but in this study, it should be placed on the same PCB for easy implementation and the direction of each antenna are aligned to be a cross($90^{\circ}$) position. The study is carried out by comparing the radiation patterns mainly, and the theoretical expectation and the computer simulation are also executed. The final model is the folded IF-antennas system printed on PCB and the ideal dipole-antenna arrangement in also test to verify the possibility of our implementation. And it is finally proved by measuring experiments.

• 한국생산제조학회지
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• 제23권2호
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• pp.118-126
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• 2014

In this paper, a new method is proposed for the five-degree-of-freedom precision alignment and stitching of three-dimensional surface-profile data sets. The control parameters for correcting thealignment error are calculated from the surface profile data for overlapped areas among the adjacent measuring areas by using the "least squares method" and "maximum lag position of cross correlation function." To ensure the alignment and stitching reliability, the relationships betweenthe alignment uncertainty, overlapped area, and signal-to-noise level of the measured profile data are investigated. Based on the results of this uncertainty analysis, an appropriate size is proposed for the overlapped area according to the specimen's surface texture and noise level.

• Journal of Astronomy and Space Sciences
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• 제36권4호
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• pp.235-248
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• 2019

This paper suggests a relative orbit control strategy for the CubeSat Astronomy by NASA and Yonsei using Virtual Telescope Alignment eXperiment (CANYVAL-X) mission whose main goal is to demonstrate an essential technique, which is an arrangement among two satellites and a specific celestial object, referred to as inertial alignment, for a next-generation virtual space telescope. The inertial alignment system is a relative orbit control system and has requirements for the relative state. Through the proposed orbit control strategy, consisting of separation, proximity keeping, and reconfiguration, the requirements will be satisfied. The separation direction of the two CubeSats with respect to the orbital plane is decided to provide advantageous initial condition to the orbit controller. Proximity keeping is accomplished by differential atmospheric drag control (DADC), which generates acceleration by changing the spacecraft's effective cross section via attitude control rather than consuming propellant. Reconfiguration is performed to meet the requirements after proximity keeping. Numerical simulations show that the requirements can be satisfied by the relative orbit control strategy. Furthermore, through numerical simulations, it is demonstrated that the inertial alignment can be achieved. A beacon signal had been received for several months after the launch; however, we have lost the signal at present.

• Physical Therapy Rehabilitation Science
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• 제5권2호
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• pp.84-88
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• 2016

Objective: Generally, it is known that there is a correlation between excessive calcaneus eversion and a patient with low back pain and it also affects pelvic alignment. However, there are not enough studies that show calcaneal eversion having an effect on the alignment of the trunk. Design: Cross-sectional study. Methods: A 3-dimensional motion analysis system was used to assess the lower limbs, pelvic alignment, and trunk alignment with increased unilateral and bilateral calcaneal eversion in twenty-one subjects. All subjects were asked to maintain a static posture for seven seconds on a wedge three times per posture for measurement and analysis purposes. The wedge used in the process was a lateral wedge with a 10-degree tilt to the lateral direction. To unify all of the subjects' foot position, the front and inner side of the wedge were marked. The height of the tilted wedge's inner side and flat wedge were balanced equally in order to be able to maintain the lateral part of the foot to the same height when producing an increased calcaneal eversion. Results: Comparing the changes in trunk and pelvic alignment in accordance to calcaneal eversion for each posture, there was a significant different in the X and Y-axis for each posture, but not in the Z-axis (p<0.05). Thus, it can be confirmed that calcaneal eversion in the sagittal plane and frontal plane may have and effect on the pelvis and the trunk. Conclusions: Postures with increased bilateral and unilateral calcaneal eversion has an effect on pelvic alignment, but does not cause any changes in trunk alignment.

• 대한치과의사협회지
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• 제17권5호통권120호
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• pp.345-350
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• 1979

The patient, 16 years female, complained of anterior cross-bite and retrusion of maxilla. Mandibular incisors occluded labially to maxillary incisors. Normally developed mandibular arch in normal elation to facial line, S-N-Pog was within normal range. Cross-bite of anterior teeth was corrected by means of Class III elastics under multibanded system. Space for alignment of crowding of upper anterior teeth was regained by means of cervical headgear and sliding yoke. She gained good alignment of anterior teeth and attractive facial profile after 2 years.

• ETRI Journal
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• 제38권2호
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• pp.376-386
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• 2016

Currently, web applications are gaining in prevalence. In a web application, an input may not be appropriately validated, making the web application susceptible to cross-site scripting (XSS), which poses serious security problems for Internet users and websites to whom such trusted web pages belong. A taint inference is a type of information flow analysis technique that is useful in detecting XSS on the client side. However, in existing techniques, two current practical issues have yet to be handled properly. One is URL rewriting, which transforms a standard URL into a clearer and more manageable form. Another is HTML sanitization, which filters an input against blacklists or whitelists of HTML tags or attributes. In this paper, we make an analogy between the taint inference problem and the molecule sequence alignment problem in bioinformatics, and transfer two techniques related to the latter over to the former to solve the aforementioned yet-to-be-handled-properly practical issues. In particular, in our method, URL rewriting is addressed using local sequence alignment and HTML sanitization is modeled by introducing a removal gap penalty. Empirical results demonstrate the effectiveness and efficiency of our method.

• 한국도로학회논문집
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• 제8권2호
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• pp.105-116
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• 2006

본 논문은 차량에 각종 센서를 장착한 도로안전성 조사 분석 차량을 이용하여 도로의 횡단경사를 측정하는 방법에 관해 소개하였다. 횡단경사는 평면선형, 종단선형과 더불어 도로 설계의 중요한 요소이며, 도로의 안전성을 평가하는 데에도 필수적인 요소이다. 그러나 횡단경사의 경우 도로의 잦은 덧씌우기로 도면과 다르게 나타날 수 있으며, 교통량이 많은 도로에서 횡단경사를 측정하는 데에는 많은 어려움이 존재한다. 이에 본 연구에서는 GPS/INS 및 레이저 스캐너 등을 장착한 도로 안전성 조사 분석 차량으로 주행 종횡단경사를 측정하는 알고리즘을 개발하였다. 또, 현장에서 개발된 알고리즘의 적용성을 검토하기 위해 횡단경사 중 편경사가 설치된 곡선구간을 선택하여 레이저 스캐너와 GPS/INS 통합시스템을 사용하여 주행중 편경사를 측정하고. 이를 통계적으로 검증하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.34-39
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• 1993

Presented in this paper is a complete error covariance analysis for strapdown inertial navigation system(SDINS). We have found that in SDINS the cross-coupling terms in gyrocompass alignment errors can significantly influence the SDINS error propagation. Initial heading error has a close correlation with the east component of gyro bias erro, while initial level tilt errors are closely related to accelerometer bias errors. In addition, pseudo-state variables are introduced in covariance analysis for SDINS utilizing the characteristics of gyrocompass alignment errors. This approach simplifies the covariance analysis because it makes the initial error covariance matrix to a diagonal form. Thus a real implementation becomes easier. The approach is conformed by comparing the results for a simplified case with the covariance analysis obtained from the conventional SDINS error model.