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최재욱(Choi, Jaewook),정은빈(Jeong, Eunbeen),박성표(Park, Sungpyo),김태완(Kim, Tae-Wan),이찬식(Lee, Chansik) 대한건축학회 2019 대한건축학회 학술발표대회 논문집 Vol.39 No.2
As apartments built to address overcrowding in the Seoul metropolitan area have become dilapidated, the housing performance has been reduced and the shortage of parking lots has become more serious. Parking lots can be secured by remodeling, but there are not enough cases. The study aims to develop WBS for expansion of underground parking lots, drawing detailed work to calculate construction costs. The derived WBSs were applied to the case complex and analyzed. As a result, 12 activities were derived for Alternative 1(extended after its existence) and 24 activities for Alternative 2(extended after demolition).
Park, Sang Eun,Song, Ji Hoon,Hong, Chansik,Kim, Dong Eun,Sul, Jee-Won,Kim, Tae-Youn,Seo, Bo-Ra,So, Insuk,Kim, Sang-Yeob,Bae, Dong-Jun,Park, Mi-Ha,Lim, Hye Min,Baek, In-Jeoung,Riccio, Antonio,Lee, Joo- Springer US 2019 Molecular Neurobiology Vol.56 No.4
<P>Oxidative stress is a key mediator of neuronal death in acute brain injuries, such as epilepsy, trauma, and stroke. Although it is accompanied by diverse cellular changes, increases in levels of intracellular zinc ion (Zn<SUP>2+</SUP>) and calcium ion (Ca<SUP>2+</SUP>) may play a critical causative role in oxidative neuronal death. However, the mechanistic link between Zn<SUP>2+</SUP> and Ca<SUP>2+</SUP> dyshomeostasis in neurons during oxidative stress is not well-understood. Here, we show that the exposure of cortical neurons to H<SUB>2</SUB>O<SUB>2</SUB> led to a zinc-triggered calcium influx, which resulted in neuronal death. The cyclin-dependent kinase inhibitor, NU6027, inhibited H<SUB>2</SUB>O<SUB>2</SUB>-induced Ca<SUP>2+</SUP> increases and subsequent cell death in cortical neurons, without affecting the early increase in Zn<SUP>2+</SUP>. Therefore, we attempted to identify the zinc-regulated Ca<SUP>2+</SUP> pathway that was inhibited by NU6027. The expression profile in cortical neurons identified transient receptor potential cation channel 5 (TRPC5) as a candidate that is known to involve in the generation of epileptiform burst firing and epileptic neuronal death (Phelan KD et al. 2012a; Phelan KD et al. 2013b). NU6027 inhibited basal and zinc-augmented TRPC5 currents in TRPC5-overexpressing HEK293 cells. Consistently, cortical neurons from TRPC5 knockout mice were highly resistant to H<SUB>2</SUB>O<SUB>2</SUB>-induced death. Moreover, NU6027 is neuroprotective in kainate-treated epileptic rats. Our results demonstrate that TRPC5 is a novel therapeutic target against oxidative neuronal injury in prolonged seizures and that NU6027 is a potent inhibitor of TRPC5.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (10.1007/s12035-018-1258-7) contains supplementary material, which is available to authorized users.</P>
Park, Sul Gee,Cho, Deuk Jae,Park, Chansik The Institute of Positioning 2012 Journal of Positioning, Navigation, and Timing Vol.1 No.1
Due to inaccurate safe navigation estimates, maritime accidents have been occurring consistently. In order to solve this, the precise positioning technology using carrier phase information is used, but due to high buildings near inland waterways or inclination, satellite signals might become weak or blocked for some time. Under this weak signal environment for some time, the GPS raw measurements become less accurate so that it is difficult to search and maintain the integer ambiguity of carrier phase. In this paper, a method to generate code and carrier phase measurements under this environment and maintain resilient navigation is proposed. In the weak signal environment, the position of the receiver is estimated using an inertial sensor, and with this information, the distance between the satellite and the receiver is calculated to generate code measurements using IGS product and model. And, the carrier phase measurements are generated based on the statistics for generating fractional phase. In order to verify the performance of the proposed method, the proposed method was compared for a fixed blocked time. It was confirmed that in case of a weak or blocked satellite signals for 1 to 5 minutes, the proposed method showed more improved results than the inertial navigation only, maintaining stable positioning accuracy within 1 m.
Implementation of Vehicle Navigation System using GNSS, INS, Odometer and Barometer
Park, Jungi,Lee, DongSun,Park, Chansik The Institute of Positioning 2015 Journal of Positioning, Navigation, and Timing Vol.4 No.3
In this study, a Global Navigation Satellite System (GNSS) / Inertial Navigation System (INS) / odometer / barometer integrated navigation system that uses a commercial navigation device including Micro Electro Mechanical Systems (MEMS) accelerometer and gyroscope in addition to GNSS, odometer information obtained from a vehicle, and a separate MEMS barometer sensor was implemented, and the performance was verified. In the case of GNSS and GNSS/INS integrated navigation system that are generally used in a navigation device, the performance would deteriorate in areas where GNSS signals are not available. Therefore, an integrated navigation system that calculates a better navigation solution in areas where GNSS signals are not available compared to general GNSS/INS by correcting the velocity error of GNSS/INS using an odometer and by correcting the cumulative altitude error of GNSS/INS using a barometer was suggested. To verify the performance of the navigation system, a commercial navigation device (Softman, Hyundai Mnsoft, http://www.hyundai-mnsoft.com) and a barometer sensor (ST Company) were installed at a vehicle, and an actual driving test was performed. To examine the performance of the algorithm, the navigation solutions of general GNSS/INS and the GNSS/INS/odometer/barometer integrated navigation system were compared in an area where GNSS signals are not available. As a result, a navigation solution that has a smaller position error than that of GNSS/INS could be obtained in the area where GNSS signals are not available.
Park, Kwi Woo,Chae, Jeong Geun,Song, Se Phil,Son, Seok Bo,Choi, Seungho,Park, Chansik The Institute of Positioning 2017 Journal of Positioning, Navigation, and Timing Vol.6 No.1
In this study, to design a multi-GNSS receiver using single RF front-end, the receiving performances for various frequency plans were evaluated. For the fair evaluation and comparison of different frequency plans, the same signal needs to be received at the same time. For this purpose, two synchronized RF front-ends were configured using USRP X310, and PC-based software was implemented so that the quality of the digital IF signal received at each front-end could be evaluated. The software consisted of USRP control, signal reception, signal acquisition, signal tracking, and C/N0 estimation function. Using the implemented software and USRP-based hardware, the signal receiving performances for various frequency plans, such as the signal attenuation status, overlapping of different systems, and the use of imaginary or real signal, were evaluated based on the C/N0 value. The results of the receiving performance measurement for the various frequency plans suggested in this study would be useful reference data for the design of a multi-GNSS receiver in the future.
A Design and Implementation of Software Defined Radio for Rapid Prototyping of GNSS Receiver
Park, Kwi Woo,Yang, Jin-Mo,Park, Chansik The Institute of Positioning 2018 Journal of Positioning, Navigation, and Timing Vol.7 No.4
In this paper, a Software Defined Radio (SDR) architecture was designed and implemented for rapid prototyping of GNSS receiver. The proposed SDR can receive various GNSS and direct sequence spread spectrum (DSSS) signals without software modification by expanded input parameters containing information of the desired signal. Input parameters include code information, center frequency, message format, etc. To receive various signal by parameter controlling, a correlator, a data bit extractor and a receiver channel were designed considering the expanded input parameters. In navigation signal processing, pseudorange was measured based on Coordinated Universal Time (UTC) and appropriate navigation message decoder was selected by message format of input parameter so that receiver position can be calculated even if SDR is set up various GNSS combination. To validate the proposed SDR, the software was implemented using C++, CUDA C based on GPU and USRP. Experimentation has confirmed that changing the input parameters allows GPS, GLONASS, and BDS satellite signals to be received. The precision of the position from implemented SDR were measured below 5 m (Circular Error Probability; CEP) for all scenarios. This means that the implemented SDR operated normally. The implemented SDR will be used in a variety of fields by allowing prototyping of various GNSS signal only by changing input parameters.
An Efficient Positioning Method for Multi-GNSS with Multi-SBAS
Park, Kwi Woo,Cho, MinGyou,Park, Chansik The Institute of Positioning 2018 Journal of Positioning, Navigation, and Timing Vol.7 No.4
The current SBAS service does not provide a method to integrate multiple SBAS corrections. This paper proposes a positioning method to effectively integrate multiple SBAS and multiple GNSS. In the method, the final position is obtained by the weighted sum of the positions obtained from the combination of GNSS and SBAS. Since each position is independently computed and combined using flexible weights, it has a simple structure that can easily cope with various environments. In order to verify the operation and performance of the proposed method, raw measurements of GNSS and SBAS were collected using commercial receivers. The experiments using real signals show that the combined use of two SBAS corrections was more accurate by 0.05~0.4m(2dRMS) than using only one SBAS correction. To improve the position accuracy, this paper considered the integration of multi-GNSS and multi-SBAS, which was not found in other existing studies. The proposed method is expected to be a core technology for designing multi-GNSS navigation receivers considering multi-SBAS corrections. The importance of the method will be increased as KPS and KASS also available in near future.
Implementation and Performance Analysis of Multi-GNSS Signal Collection System using Single USRP
Park, Kwi Woo,Choi, Yun Sub,Lee, Min Joon,Lee, Sang Jeong,Park, Chansik The Institute of Positioning 2016 Journal of Positioning, Navigation, and Timing Vol.5 No.1
In this paper, a system that can collect GPS L1 C/A, GLONASS G1, and BDS B1I signals with single front-end receiver was implemented using a universal software radio peripheral (USRP) and its performance was verified. To acquire the global navigation satellite system signals, hardware was configured using USRP, antenna, external low-noise amplifier, and external oscillator. In addition, a value of optimum local oscillator frequency was selected to sample signals from three systems with L1-band with a low sampling rate as much as possible. The comparison result of C/N0 between the signal collection system using the proposed method and commercial receiver using double front-end showed that the proposed system had 0.7 ~ 0.8dB higher than that of commercial receiver for GPS L1 C/A signals and 1 ~ 2 dB lower than that of commercial receiver for GLONASS G1 and BDS B1I. Through the above results, it was verified that signals collected using the three systems with a single USRP had no significant error with that of commercial receiver. In the future, it is expected that the proposed system will be combined with software-defined radio (SDR) and advanced to a receiver that has a re-configuration channel.