• Title/Summary/Keyword: Digital power control

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Factors Affecting the Confidence of Nursing Students in the On-line-Based Education by COVID-19 (COVID-19로 인한 온라인 중심 교육에서 간호대학생의 핵심 기본 간호술 수행 자신감에 영향을 미치는 요인)

  • Cha, Hye-gyeong;Kim, Han-Song
    • Journal of Digital Convergence
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    • v.20 no.1
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    • pp.459-469
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    • 2022
  • This study aims to provide basic data for the development of teaching methods to improve the performance confidence of performing core basic nursing skills in nursing students while availing of online education owing to COVID-19. Data were collected from 146 students in the Department of Nursing at N University located in C city. The collected data was analyzed using descriptive statistics, difference, correlation analysis, and multiple regression by using SPSS 23.0 program.. The subjects' performance confidence of core basic nursing skills was dependent on self-directed learning readiness (r=.368, p<.001), intrinsic goal motivation (r=.232, p=.005), extrinsic goal motivation (r=.344, p<.001), task value (r=.237, p=<.001), control of learning beliefs (r=.262, p=<.001), and self-efficacy for learning and performance (r=.443), p<.001) with a significant positive correlation. The results indicate that the factors influencing the subjects' performance confidence of core basic nursing skills were the 4th grade (β=0.413, p<.001), extrinsic goal motivation (β=0.307, p<.001), and self-efficacy for learning and performance (β=0.316, p=.005), and the explanatory power was 35.8% (F=8.354, p<.001). The research results showed that it is necessary to develop and apply various online-centered teaching and learning methods to increase the extrinsic goal motivation and self-efficacy for learning and performance of nursing students to enhance their performance confidence of core basic nursing skills. This will serve as a basis for preparing effective online centered nursing education strategies to improve performance confidence of core basic nursing skills.

Factors affecting Mental health of high school students -Focused on the general high school students in the 3rd grade- (일 지역 고등학생의 정신건강 영향요인 -일반계 고등학교 3학년을 중심으로-)

  • Jeong, Kyeong-Sook
    • Journal of Digital Convergence
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    • v.20 no.1
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    • pp.391-398
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    • 2022
  • The aim of this study was to identify the factors affecting the mental health of high school students. The participants comprised 216 students in general high school. Data collection was conducted from May 1, 2020 to May 20, 2020. The data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient and a multiple regression analysis. The average score for self-esteem was 3.75±0.64(1-5), perceived stress was 2.86±0.58(1-5), emotional regulation ability was 3.43±0.65(1-5) and mental health was 1.91±0.71(1-5). Mental health had a statistically significant relationship with self-esteem(r=-.64, p<.001), emotional regulation ability(r=-.61, p<.001) and perceived stress(r=.54, p<.001). The factors affecting mental health were self-esteem(β=.46, p<.001), emotional regulation ability(β=-.37, p<.001), negative perceived stress(β=.17, p=.001) ; the explanatory power of the model was 60.0%. Therefore, it will be necessary to develop a program that can help high school students improve their self-esteem and control their negative emotions in order to promote their mental health.

A Study on the Effective Controlling System of Radio-activity Ventilation (RI사용 의료기관의 효율적인 배기관리 방안)

  • Lee, Kyung-Jae;Lee, Jin-Hyung;Kim, Kyung-Hoon;Kwack, Dong-Woo;Jo, Hyun-Duck;Ko, Kil-Man;Park, Young-Jae;Lee, In-Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.1
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    • pp.91-98
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    • 2008
  • Purpose: Radio-isotopes (RI) use has been steadily developing due to industrial and technical development in the modern medical society. Particularly, popularization of domestic cyclotrons dramatically enable hospitals to produce and use diagnostic radio-isotopes. Generally, only specific facilities such as hospitals, research institutes, nuclear power plants and universities can use radio-isotopes, they are also responsible for ventilation system. The strength of radioactivity in the air is strongly regulated and controlled by korea atomic energy law in Korea Institue of Nuclear Safety (KINS), so that air radioactivity exposure can lead to environmental pollution surrounding places. In this study, we'd like to find out the investigation and the present condition of the controlled ventilation system in domestic hospitals by an emission standard from KINS, and try to reach an agreement about how to use the ventilation system. Result: Definition of filters, features and structures of pre-filters, hepa-filters, charcol filters, filter exchange procedures and precautions are explained. RI deflation concentration and filter exchange cycle have been presented as a standard prescribed in the rules of KINS. The Radiation Control Management System (RCMS) introduced by Seoul National University Bundang Hospital linking to digital pressure gauge with computer controller in another medical facilities were described in details. Conclusions: The system of medical facilities using RI has been remarkably developing in 21 century. Especially, radiation safety control system has also been grown rapidly into the subdivision, specialization, advanced technology along with international technical improvement. However, As far as current RI ventilation system is concerned, it has nothing better than doing in the past. Preferentially, to reinforce this, more sophisticated system with strict periodic filter exchange and exhaust air control guidance should be introduced by applying brilliant domestic information technology for RCMS and digital gauge method. From personal point of view as a radiation safety manager, I have provide with present problems and improvements. Futhermore, more improved guidance should be conducted.

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Monitoring of Mythimna separata Adults by Using a Remote-sensing Sex Pheromone Trap (원격감지 성페로몬트랩을 이용한 멸강나방(Mythimna separata) 성충 예찰)

  • Jung, Jin Kyo;Seo, Bo Yoon;Cho, Jum Rae;Kim, Yong
    • Korean journal of applied entomology
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    • v.52 no.4
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    • pp.341-348
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    • 2013
  • We desinged and evaluated a remote-sensing sex pheromone trap for real-time monitoring of Mythimna separata (Lepidoptera: Noctuidae), a migratory insect in Korea. The system consisted of a modified cone-trap with a sex pheromone lure, a sensing module based on light interruption, a signal transmission module based on code division multiple access, a main electronic board for system control, a power supply based on a solar collector, a stainless steel-pole supporting the system, and a signal collection and display system based on an internet web page. The ratio (>92%) of the actual number of insects to the signal number in the remote-sensing trap was improved by sensing only within a limited period at night on the basis of the insect's circadian rhythm, control of signal sensitivity on the basis of sensing software programming, 1-h interval for signal transmission, and adjustment of the signal transmission program. The signal occurrence pattern in the remote-sensing trap was conclusively similar (correlation coefficient, >0.98) to the actual pattern of adult occurrence in the trap. The result indicated that the remote-sensing trap based on the attraction of the sex pheromone lure for M. separata has a promising potential for practical use. Occurrence of M. separata adults was observed several times in 2011 and 2012, and the peaks were sharp.

Design and Experiment of Ku_band Linear Active Phased Array Antenna System (Ku 대역 선형 능동 위상 배열 안테나 시스템 설계 및 실험)

  • Ryu Sung-Wook;Eom Soon-Young;Yun Jae-Hoon;Jeon Soon-Ick;Kim Nam
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.7 s.110
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    • pp.694-705
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    • 2006
  • In this paper, the linear active phased array antenna system operated in Ku DBS band was designed and experimented. The antenna system was composed of sixteen radiating active channels and Wilkinson power combiners with 16-channel inputs, a stabilizing DC bias and phase control board. Electrical beams of the antenna system can be formed by controling the phase-states of 3-bit digital phase shifter inside each active channel by virtue of the phase control board. The amplitude and phase deviations measured between active channels were less than ${\pm}0.8dB$ and ${\pm}15^{\circ}$, respectively, and the noise figure of each active channel was measured less than 1.2 dB in the operating band. The measured performances of the overall antenna system showed the antenna gain of more than 23.07 dBi and the sidelobe level of less than -11.17 dBc, and the bore-sight cross-polarization level of less than -12.75 dBc in the operating band. Also, by phase-controlling active channels, the beam scan patterns at $10^{\circ},\;20^{\circ},\;30^{\circ}$ were measured, and the losses caused by the corresponding beam scanning were 1.1 dB, 2.5 dB and 3.6 dB from the measurements, respectively.

A Study on the Possibility for Incident Investigation Using PLC Logs (PLC 로그의 사고조사 활용 가능성에 관한 연구)

  • Chang, Yeop;Kim, Taeyeon;Kim, Woo-Nyon
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.30 no.4
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    • pp.745-756
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    • 2020
  • An ICS(industrial control system) is a complex system that safely and efficiently monitors and controls industrial processes such as electric power, water treatment, transportation, automation plants and chemical plants. Because successful cyber attacks targeting ICS can lead to casualties or serious economic losses, it becomes a prime target of hacker groups sponsored by national state. Cyber campaigns such as Stuxnet, Industroyer and TRITON are real examples of successful ICS attacks, and were developed based on the deep knowledge of the target ICS. Therefore, for incident investigation of ICSs, inspectors also need knowledge of control processes and accident investigation techniques specialized for ICSs. Because there is no applicable technology, it is especially necessary to develop techniques and tools for embedded controllers located at cyber and physical boundaries. As the first step in this research, we reviewed logging capability of 4 PLC(Programmable Logic Controller)s widely used in an ICS area, and checked whether selected PLCs generate logs that can be used for digital investigation in the proposed cyber attack scenario.

The Design of an Auto Tuning PI Controller using a Parameter Estimation Method for the Linear BLDC Motor (선형 추진 BLDC 모터에 대한 파라미터 추정 기법을 이용하는 오토 튜닝(Auto Tuning) PI 제어기 설계)

  • Cha Young-Bum;Song Do-Ho;Koo Bon-Min;Park Moo-Yurl;Kim Jin-Ae;Choi Jung-Keyng
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.4
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    • pp.659-666
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    • 2006
  • Servo-motors are used as key components of automated system by performing precise motion control as accurate positioning and accurate speed regulation in response to the commands from computers and sensors. Especially, the linear brushless servo-motors have numerous advantages over the rotary servo motors which have connection with the friction induced transfer mechanism such as ball screws, timing belts, rack/pinion. This paper proposes an estimation method of unknown motor system parameters using the informations from the sinusoidal driving type linear brushless DC motor dynamics and outputs. The estimated parameters can be used to tune the controller gain and a disturbance observer. In order to meet this purpose high performance Digital Signal Processor, TMS320F240, designed originally for implementation of a Field Oriented Control(FOC) technology is adopted as a controller of the liner BLDC servo motor. Having A/D converters, PWM generators, rich I/O port internally, this servo motor application specific DSP play an important role in servo motor controller. This linear BLDC servo motor system also contains IPM(Intelligent Power Module) driver and hail sensor type current sensor module, photocoupler module for isolation of gate signals and fault signals.

A Low Area and High Efficiency SMPS with a PWM Generator Based on a Pseudo Relaxation-Oscillating Technique (Pseudo Relaxation-Oscillating 기법의 PWM 발생기를 이용한 저면적, 고효율 SMPS)

  • Lim, Ji-Hoon;Wee, Jae-Kyung;Song, Inchae
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.11
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    • pp.70-77
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    • 2013
  • We suggest a low area and high efficiency switched-mode power supply (SMPS) with a pulse width modulation (PWM) generator based on a pseudo relaxation-oscillating technique. In the proposed circuit, the PWM duty ratio is determined by the voltage slope control of an internal capacitor according to amount of charging current in a PWM generator. Compared to conventional SMPSs, the proposed control method consists of a simple structure without the filter circuits needed for an analog-controlled SMPS or the digital compensator used by a digitally-controlled SMPS. The proposed circuit is able to operate at switching frequency of 1MHz~10MHz, as this frequency can be controlled from the selection of one of the internal capacitors in a PWM generator. The maximum current of the core circuit is 2.7 mA, and the total current of the entire circuit including output buffer driver is 15 mA at 10 MHz switching frequency. The proposed SMPS has a simulated maximum ripple voltage of 7mV. In this paper, to verify the operation of the proposed circuit, we performed simulation using Dongbu Hitek BCD $0.35{\mu}m$ technology and measured the proposed circuit.

A Design of Wireless Sensor Node Using Embedded System (임베디드 시스템을 활용한 무선 센서 노드설계)

  • Cha, Jin-Man;Lee, Young-Ra;Park, Yeon-Sik
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.3
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    • pp.623-628
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    • 2009
  • The emergence of compact and low-power wireless communication sensors and actuators in the technology supporting the ongoing miniaturization of processing and storage allows for entirely the new kinds of embedded systems. These systems are distributed and deployed in environments where they may have been designed into a particular control method, and are often very dynamic. Collection of devices can communicate to achieve a higher level of coordinated behavior. Wireless sensor nodes deposited in various places provide light, temperature, and activity measurements. Wireless sensor nodes attached to circuits or appliances sense the current or control the usage. Together they form a dynamic and multi-hop routing network connecting each node to more powerful networks and processing resources. Wireless sensor networks are a specific-application and therefore they have to involve both software and hardware. They also use protocols that relate to both applications and the wireless network. Wireless sensor networks are consumer devices supporting multimedia applications such as personal digital assistants, network computers, and mobile communication devices. Wireless sensor networks are becoming an important part of industrial and military applications. The characteristics of modem embedded systems are the capable of communicating adapting the different operating environments. In this paper, We designed and implemented sensor network system which shows through host PC sensing temperature and humidity data transmitted for wireless sensor nodes composed wireless temperature and humidity sensor and designs sensor nodes using embedded system with the intention of studying USN.

Design and Implementation of Adaptive Beam-forming System for Wi-Fi Systems (무선랜 시스템을 위한 적응형 빔포밍 시스템의 설계 및 구현)

  • Oh, Joohyeon;Gwag, Gyounghun;Oh, Youngseok;Cho, Sungmin;Oh, Hyukjun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.9
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    • pp.2109-2116
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    • 2014
  • This paper presents the implementation and design of the advanced WI-FI systems with beam-forming antenna that radiate their power to the direction of user equipment to improve the overall throughput, contrast to the general WI-FI systems equipped with omni-antenna. The system consists of patch array antenna, DSP, FPGA, and Qualcomm's commercial chip. The beam-forming system on the FPGA utilizes the packet information from Qualcomm's commercial chip to control the phase shifters and attenuators of the patch array antenna. The PCI express interface has been used to maximize the communication speed between DSP and FPGA. The directions of arrival of users are managed using the database, and each user is distinguished by the MAC address given from the packet information. When the system wants to transmit a packet to one user, it forms beams to the direction of arrival of the corresponding user stored in the database to maximize the throughput. Directions of arrival of users are estimated using the received preamble in the packet to make its SINR as high as possible. The proposed beam-forming system was implemented using an FPGA and Qualcommm's commercial chip together. The implemented system showed considerable throughput improvement over the existing general AP system with omni-directional antenna in the multi-user communication environment.