• JSTS:Journal of Semiconductor Technology and Science
• /
• v.14 no.2
• /
• pp.198-201
• /
• 2014

The phase frequency detector (PFD) is one of the most important building blocks of a phase locked Loop (PLL). Due to blind-zone problem, the detection range of the PFD is low. The blind zone of a PFD directly depends upon the reset time of the PFD and the pre-charge time of the internal nodes of the PFD. Taking these two parameters into consideration, a PFD is designed to achieve a small blind zone closer to the limit imposed by process-voltage-temperature variations. In this paper an enhanced architecture is proposed for dynamic logic PFD to minimize the blind-zone problem. The techniques used are inverter sizing, transistor reordering and use of pre-charge transistors. The PFD is implemented in 180 nm technology with supply voltage of 1.8 V.

• Korean Journal of Social Welfare Studies
• /
• v.47 no.1
• /
• pp.179-204
• /
• 2016

The purpose of this study is to establish the concept of the blind zone of social services and analyzing the conditions by children, the elderly, the disabled, and the poor. This study used the raw data of demand/supply of social service and sample size is 4,038. Results of the study were as follows. First, in terms of the coverage, the biggest blind zones of social service are the employment support and cultural service. These results were similar for all households. But, it is noteworthy that the size and proportion of blind zones of housing support services for children, counseling services for elderly are relatively big. Second, in terms of adequacy, the most serious blind zones of social service are health and the employment support service. Especially, the elderly, the disabled, and the poor are not the most adequate adult care services and children are community service. Based on such findings, this study suggests expansion of employment support services and health care, monitoring for the services analyzed to be over-supply, and intensive involvement of private sectors about the services provided by the government of a large blind zone.

• Journal of the Korean Solar Energy Society
• /
• v.31 no.6
• /
• pp.111-124
• /
• 2011

The objective of this study is to develop the blind control strategy and method which reduce negative effect of incoming daylight on visual comfort of occupants, minimize psychological anxieties caused by frequent motions of a blind, and maximize positive effect of incoming daylight by opening/closing of a blind. In previous researches on blind controls, major problem is that the time interval and amount of blind movement do not meet the control objective at the inflected zone of solar profile curve. To overcome these limitations revealed in theprevious researches, following tasks were performed in this study. i)To establish the control objective to accomplish the goal of this study. ii)To develop the control methods and algorithms which prevent glare on the work-plane at any time and which control the time interval and amount of blind movement to follow the control objective at various solar profile angle curves. This study proposed the control strategy and method that define the base control section implying the inflection point within the control objective zone and subsequently, divide the control sections for the residual time zones. The proposed strategy and method are found to increase the incoming daylight and solar irradiation by 0 to 15 %.

• KIEAE Journal
• /
• v.14 no.3
• /
• pp.31-38
• /
• 2014

The purpose of this study is to analyse PMV (Predicted Mean Vote) and PPD (Predicted Percentage of dissatisfied) by automatic control of slat-type vertical blind. EnergyPlus, a building energy analysis software has been used for this study. The energy model is calibrated in Energy Plus using measured zone temperature and glass surface temperature data for one day and thermal comfort performance inside the building analysis was carried out. The calibrated data has the MBE of 4% and Cv(RMSE) of 10%. The result was that, for better zone thermal comfort, installation of blind on the outside is more appropriate than inside or no blind case. Additionally, different glazing types were compared and it was found that Triple Low-e glass is the most favorable.

• Journal of the Korean housing association
• /
• v.23 no.1
• /
• pp.27-41
• /
• 2012

The objective of this study is to develop the blind control strategy and method which reduce negative effect of incoming daylight on visual comfort of occupants, minimize psychological anxieties caused by frequent motions of a blind, and maximize positive effect of incoming daylight and solar irradiation by opening/closing of a blind. As previous researches on blind controls have limited outdoor environmental conditions to those in specific regions, orientations and dates, these resulted in problems at various conditions for general-purpose application. Major problem is that the time interval and amount of blind movement do not meet the control objective at the end of control zone and discontinuous curve. To overcome these limitations revealed in the previous researches, following tasks were performed in this study. 1) To establish the control objective to accomplish the goal of this study. 2) To develop the control methods and algorithms which prevent glare on the work-plane at any time and which control the time interval and amount of blind movement to follow the control objective at various profile angle curves. 3) To validate the general-purpose applicability and performance of the developed control methods and algorithms by simulation and its data analysis at various conditions. It was found that the proposed methods and algorithms can prevent the direct glare on the work-plane at all the time and also increase the incoming daylight and solar irradiation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.162-164
• /
• 2022

Efforts are being made to prevent traffic accidents within the child protection zone. Efforts are being made to prevent accidents by enacting safety facilities and laws to prevent traffic accidents in the school zone. However, traffic accidents in school zones continue to occur. If the driver can know the situation in the child protection zone in advance, accidents can be reduced. In this paper, we design a camera that eliminates blind spots in school zones and a number recognition camera system that can collect pre-traffic information. Design a LIDAR system that recognizes vehicle speed and pedestrians. Design an LED guidance system that delivers information to drivers without smart devices. We study time series analysis and artificial intelligence algorithms that collect and process pedestrian and vehicle information recognized by cameras and LIDAR. In the artificial intelligence traffic accident prevention system learned by deep learning, before entering the school zone, the school zone information is sent to the driver through the Force Push Service and the school zone information is delivered to the driver on the LED sign. try to reduce accidents.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.398-398
• /
• 2000

Since there is a blind zone in driver's view around the excavator, industrial accidents between the equipment and the workers within the zone have been occurred frequently. The purpose of this paper is to develop a obstacle recognition system which can prevent such an accident by providing the driver with the information on direction and distance of the obstacle within the blind zone. We designed the ultrasonic sensor based obstacle recognition system which consists of sensor arrays and a control unit connected via CAN(controller area network). The Cross-correlation technique and histogramic probability distribution method are used as a reliable obstacle detection algorithms to remove the environmental noise. The experimental results using a real excavator show the effectiveness of the system.

• ETRI Journal
• /
• v.36 no.6
• /
• pp.894-904
• /
• 2014

Blind mismatch correction of time-interleaved analog-to-digital converters (TI-ADC) is a challenging task. We present a practical blind calibration technique for low-computation, low-complexity, and high-resolution applications. Its key features are: dramatically reduced computation; simple hardware; guaranteed parameter convergence with an arbitrary number of TI-ADC channels and most real-life input signals, with no bandwidth limitation; multiple Nyquist zone operation; and mixed-domain error correction. The proposed technique is experimentally verified by an M = 4 400 MSPS TI-ADC system. In a single-tone test, the proposed practical blind calibration technique suppressed mismatch spurs by 70 dB to 90 dB below the signal tone across the first two Nyquist zones (10 MHz to 390 MHz). A wideband signal test also confirms the proposed technique.

• KIEAE Journal
• /
• v.17 no.4
• /
• pp.75-81
• /
• 2017

Purpose: Most contemporary office buildings supply external views, a sense of openness and a sense of time to their occupants by adopting the curtain walls, which are equipped with an outer cover having large window area. As a result, the amount of radiation increases, adversely affecting cooling load during the summer in office buildings. Although solar radiation decreases heating load and reduces energy costs during the winter period, due to the characteristics of offices where occupants work largely during daytime, the cooling load is important compared to the heating. Therefore, diverse measures to resolve those trade-offs and annual energy cost have been investigated. Method: In this study, the annual thermal load was comparatively analyzed according to the slat angle of the venetian blind along with lighting control technique. Result: After selecting effective conditions, in order to resolve such issues, this study established automated control strategies of slat angle depending on the window-to-wall ratio and zone orientation, so that the findings of this study can be effectively generalized to other circumstances.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.17 no.2
• /
• pp.34-41
• /
• 2009

The latest vehicle yields a superior safety and reduction of driving burden by monitoring the driving state of vehicle and its environment with various sensors. To detect other vehicles and objects of the rear left and right-side blind spot area of driver, provide the information about a existence of objects inside the blind spot, and give a signal to avoid collision, this study proposes the intelligent outside rear-view mirror system. This task has substantially complicated several factors. For example, the size, geometry and features of the various vehicles which might enter the monitored zone is varied widely and therefore present various reflective characteristics. This study proposes the optimal specification and configuration of optical system and IR array sensor of blind spot detection system, and shows the results of the performance evaluation of developed system.