• Journal of Environmental Health Sciences
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• v.47 no.6
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• pp.540-547
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• 2021

Background: Indoor air pollutants are caused by a number of factors, such as coming in from the outside or being generated by internal activities. Typical indoor air pollutants include nitrogen dioxide and carbon monoxide from household items such as heating appliances and volatile organic compounds from building materials. In addition there is carbon dioxide from human breathing and bacteria from speaking, coughing, and sneezing. Objectives: According to recent research results, most indoor air pollution is known to be greatly affected by internal factors such as burning (biomass for cooking) and various pollutants. These pollutants can have a fatal effect on the human body due to a lack of ventilation facilities. Methods: We fabricated a polydopamine (PDA) layer with Ti substrates as a coating on supported glass fiber fabric to enhance its photo-activity. The PDA layer with TiO₂ was covalently attached to glass fiber fabric using the drop-casting method. The roughness and functional groups of the surface of the Ti substrate/PDA coated glass fiber fabric were verified through infrared imaging microscopy and field emission scanning electron microscopy (FE-SEM). The obtained hybrid Ti substrate/PDA coated glass fiber fabric was investigated for photocatalytic activity by the removal of ammonia and an epidermal Staphylococcus aureus reduction test with lamp (250 nm, 405 nm wavelength) at 24℃. Results: Antibacterial properties were found to reduce epidermal staphylococcus aureus in the Ti substrate/PDA coated glass fiber fabric under 405 nm after three hours. In addition, the Ti substrate/PDA coated glass fiber fabric of VOC reduction rate for ammonia was 50% under 405 nm after 30 min. Conclusions: An electron-hole pair due to photoexcitation is generated in the PDA layer and transferred to the conduction band of TiO₂. This generates a superoxide radical that degrades ammonia and removes epidermal Staphylococcus aureus.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.82-84
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• 2006

WebDAV는 IETF 표준으로서 웹상에서 분산 저작을 지원하도록 HTTP를 확장한 프로토콜이다. WebDAV 클라이언트는 WebDAV 프로토콜을 이용하여 WebDAV 서버자원을 관리하는 도구이다. 현재 WebDAV 기반의 자원 관리가 널리 사용되면서 무선 네트워크 환경에서 동작하는 클라이언트의 필요성이 증대되고 있다. 본 논문에서는 무선 네트워크를 지원하는 PDA에서 동작하는 WebDAV 클라이언트의 구현에 대하여 기술한다. 개발된 클라이언트는 간결한 사용자 인터페이스를 제공하며 WebDAV의 기본 메소드를 지원한다. 사용자는 인터페이스와 기본 메소드를 이용하여 WebDAV 서버에 자원을 등록하고, 서버 자원에 대한 열람, 검색, 이동 및 삭제를 할 수 있으며, 서버 자원을 내려 받을 수 있다. 본 클라이언트는 PDA에서 동작하기 위해서 .NET Compact Framework를 기반으로 구현 하였으며 관련 에뮬레이터를 이용하여 실험하였고 이를 실제 PDA장치인 'HP iPAQ hx2700'에 이식하여 검증하였다.

• Journal of the Ergonomics Society of Korea
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• v.24 no.3
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• pp.1-10
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• 2005

The primary objective of this study is to design input methods for assisting button selection tasks on a PDA screen. Familiar methods in the existing computing environments were investigated to develop aiding methods. Factors manipulated in the experiment included aiding method, button size, and users' prior experience with PDAs. A total of sixteen participants examined the usability of button selection tasks. Two types of button selection tasks were used as experimental tasks; one was selecting a target button, and the other was selecting multiple target buttons consecutively. The results showed that the aiding method and the button size had significant effects on the subjective satisfaction as well as the performance. In addition, users' prior experience with PDAs affected the performance significantly. The interaction between the aiding method and the button size was found to have significant effects on the performance. However, the interaction effect between the button size and the PDA experience was significant on the task performance time only for the multiple button selection tasks. Design considerations were proposed based on the experimental results. These can be applied to the PDA interaction design to make the PDAs more usable.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1833-1837
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• 2004

The two-inertia system, which has the torsion vibration, is typically found in several industrial applications. This torsion vibration will effect the quality of the rolled material as well as the stability of the drive system. Thus the speed and torsion vibration of the system have to be properly controlled. This paper, I-PDA controller designed by Coefficient Diagram Method to control a two-inertia system is proposed. The experimental result shows that both of transient and steady state specification can be fulfilled but the transient response still has long rise time. In order to improve the speed of the system response, a phase lag structure of feedforward controller is introduced to I-PDA control system. It is shown that the performance of the I-PDA control system with suitable FFC has shorter rise and settling times, no overshoot and the torsion vibration can be suppressed.

• Natural Product Sciences
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• v.24 no.3
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• pp.206-212
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• 2018

Xanthii Fructus has been traditionally used for the treatment of rhinitis, rheumatoid arthritis, and eczema. In this study, a high-performance liquid chromatography-photodiode array (HPLC-PDA) method was developed and then used for the simultaneous analysis of eight phenylpropanoids in Xanthii Fructus. The analytical column used for this separation was a $SunFire^{TM}$ $C_{18}$ column, maintained at $40^{\circ}C$. The mobile phase used was 1.0% acetic acid in distilled water and 1.0% acetic acid in acetonitrile with gradient elution. For identify of each component, the mass spectrometer (MS) was used a Waters triple quadrupole mass spectrometer requipped with electrospray ionization (ESI) source. The HPLC-PDA method showed good linearity: correlation coefficients were ${\geq}0.9996$. The limits of detection and quantification of the eight compounds were 0.02 - 0.04 and $0.06-0.14{\mu}g/mL$, respectively. The extraction recoveries ranged from 97.51 to 108.67%. The relative standard deviation values of intra- and inter-day precision were 0.06 - 1.55 and 0.09 - 1.68%, respectively. The validated HPLC-PDA method was applied to simultaneously analyse the amounts of eight phenlypropanoids in Xanthii Fructus.

• The Journal of the Korea Contents Association
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• v.3 no.1
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• pp.47-57
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• 2003

The POS(Point Of Sales) system is S/W and H/W that enables to analyse and evaluate sales information that has been collected in the real-time at point of sales by each department in the store. However, existing POS systems are mainly aiming at the large scaled store with the specific high-priced equipment, so that in applying them to a store specializing in food have weak point to use them in the cost or scale respect. In this paper, we design and implement a web based POS system with PC(Personal Computer) and PDA/(Personal Digital Assistant) in wireless internet environment to apply POS system to a store specializing in food, without specific equipments.

• The Plant Pathology Journal
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• v.26 no.2
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• pp.185-188
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• 2010

This study was undertaken to isolate and to identify a fungal pathogen Monilinia sp. KV-27 associated with apple anthracnose. Rotted Fuji apples were used for the isolation of the fungus. The infected tissues were sterilized with 70% ethanol, washed with sterilized distilled water and were transferred to 50 ml containing potato dextrose broth (PDB) flasks. The peripheral hyphae of the fungal colony which developed from the infected tissues were isolated on to potato dextrose agar (PDA). On PDA plates the fungus grew well at $25^{\circ}C$ and occupied more than half of a 9 cm petri dish within 5 days. The fungal cultures on PDA were used for morphological observation and identification of the fungus. Conidiophores were produced on the gray to whitish sporodochial structures scattered on PDA plates. These conidiophores gave rise to chains of conidia, which were branched and easily detached in water. These structures were dark brown to black and consisted of hyphal masses. Conidia produced on PDA plates were hyline or light colored, lemon shaped or ellipsoidal ($10-13{\times}8.5-11{\mu}m$) in size.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.553-558
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• 2003

The information of works performed by labors can be used for analyzing project status related to schedule, cost and productivity, etc. The purpose of this research is to develop a computer-based system by the application of PDA and barcode technology in order to measue and monitor the amount of workforce resources, works done and productivity. It is anticipated that the effective use of the devepoped system would be able to effectively assist the schedule planning and management for present and prospective construction projects.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.442-446
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• 2009

This study was undertaken to isolate and to identify a fungal pathogen Colletotrichum sp. KV-21 associated with apple anthracnose. Rotted Gala apples were used for the isolation of the fungus. The infected tissues were sterilized with 70% ethanol, washed with sterilized distilled water and were transferred to 50 ml containing potato broth (PDB) flasks. The peripheral hyphae of the fungal colony which developed from the infected tissues were isolated on to potato dextrose agar (PDA). On PDA plates the fungus grew well at $25^{\circ}C$ and occupied more than half of a 9 cm petri dish within 5 days. The fungal cultures on PDA were used for morphological observation and identification of the fungus. Conidiophores were produced on the gray to whitish sporodochial structures scattered on PDA plates which gave rise to conidiogenous cells. The structures of the conidia produced on PDA plates were subcylindrical to obovoid, fusoid, tapered and 4 to $6\;{\mu}m$ in size.

• The Journal of the Acoustical Society of Korea
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• v.21 no.3
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• pp.237-244
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• 2002

In this paper we mention the optimization of MPEG-4 VM (Moving Picture Expert Group-4 Verification Model) GA (General Audio) AAC (Advanced Audio Coding) encoder and the design of the decoder for PDA (Personal Digital Assistant) using MPEG-4 VM source. We profiled the VMC source and several optimization methods have applied to those selected functions from the profiling. Intel Pentium III 600 MHz PC, which uses windows 98 as OS, takes about 20 times of encoding time compared to input sample running time, with additional options, and about 10 times without any option. Decoding time on PDA was over 35 seconds for the 17 seconds input sample. After optimization, the encoding time has reduced to 50% and the real time decoding has achieved on PDA.