• Journal of The Korean Astronomical Society
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• v.18 no.1
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• pp.1-13
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• 1985

We present the data of photoelectric photometric observations of BW Vul carried out for four nights during the period of $1982{\sim}1984$. The light curves with asymmetric shape show a stillstand on the ascending branch at phase of ${\phi}{\approx}0.85$ just before the maximum light, and also the ampitude and shape of light curves are changed from night to night. Using all the published data, a new ephemeris of maximum time is derived, in which the period of light variation is $P=0^d.20102977$ and its increasing rate is 2.2 see/century.

• Journal of the Korean Data and Information Science Society
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• v.15 no.4
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• pp.899-910
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• 2004

In this paper we have proposed a new loss function, namely, non-linear exponential(NLINEX) loss function, which is quite asymmetric in nature. We obtained the Bayes estimator under exponential(LINEX) and squared error(SE) loss functions. Moreover, a numerical comparison among the Bayes estimators of power function distribution under SE, LINEX, and NLINEX loss function have been made.

• Environmental and Resource Economics Review
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• v.24 no.3
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• pp.523-549
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• 2015

This paper investigates an oil refiner's asymmetric behavior in the adjustments of gasoline and diesel prices to changes in his own price and his rivals' prices as well as input costs. An asymmetric error correction model which allows a firm's pricing behavior to the deviation of other firms' prices from their long-run equilibrium level is employed for estimation using weekly data for the period April 2009 to January 2015. Evidence is found that there is a significant degree of asymmetry in the adjustment of wholesale prices to changes in crude oil price. A similar result in regard to the exchange rate is also found by the data. The estimation results for firm's response to changes in other firms' prices indicates that implicit collusion could be more easily exploited in the wholesale petroleum market as results of firms' interaction with each other and anticipation of rivals' pricing behavior. A few refiners show competitive price adjustment in response to the upward deviation of the others' prices from their equilibrium level.

• Journal of the Korea Society of Computer and Information
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• v.15 no.3
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• pp.65-72
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• 2010

We propose the asymmetric 2.5Gbps/622Mbps PON(Passive Optical Network) in order to reduce the bandwith of filter at receiver with inverse RZ(Return to Zero) code coded downstream and NRZ(Non Return to Zero) upstream re-modulation. I theoretically analyze BER(Bit Error Rate) performance and the power sensitivity with the optimal threshold level by performing simulation with MATLAB according to the types of downstream data. The results have shown that the optimal threshold level at the optical receiver could be saturated at 0.33 as the optical received power increase more than -26dBm to keep $10^{-12}$ of BER to a minimum. Also the power sensitivity is more improved by about 3dB by fixing the threshold level at 0.33 than the conventional receiver. The proposed system can be a useful technology for optical access networks with asymmetric upstream and downstream data rates because the optical receiver can be used without controlling threshold levels and that does not require a light source in optical network unit (ONU) and its control circuits in the optical line termination (OLT).

• KDI Journal of Economic Policy
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• v.27 no.1
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• pp.185-209
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• 2005

This study examines ERPT with asymmetric response and both import and export market shares, using wool trade data. The study found that, asymmetric response may be as common as symmetric response. In addition, the responses (both in price and quantity demanded) to the changes in exchange rate are considerably different across goods, and even for the homogenous goods, across countries. In case of depreciation, the export price changes more than appreciation case in general, and as a result the destination price changes less. It is also found that the cases of excessive or perverse pass-through are found more frequently than reported by previous studies. This finding points out that strategic behavior of firms or unexpected response to exchange rate fluctuation takes place more frequently than we commonly expect or take, in particular at disaggregated levels. When the model considers asymmetric responses of the export price to appreciation and depreciation (of exporter's currency), the estimation provided that for 39 trade cases out of 83, export price responded to appreciation and depreciation in different fashions, although the normal response was the dominating phenomenon with 99 cases or about 60% out of 166 cases. Market shares affected the extent and direction of responses in select cases. These findings will have important implications for policy makers and traders.

• Communications for Statistical Applications and Methods
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• v.30 no.6
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• pp.577-587
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• 2023

Conventional categorical data imputation techniques, such as mode imputation, often encounter issues related to overestimation. If the variable has too many categories, multinomial logistic regression imputation method may be impossible due to computational limitations. To rectify these limitations, we propose a two-stage imputation method. During the first stage, we utilize the Boruta variable selection method on the complete dataset to identify significant variables for the target categorical variable. Then, in the second stage, we use the important variables for the target categorical variable for logistic regression to impute missing data in binary variables, polytomous regression to impute missing data in categorical variables, and predictive mean matching to impute missing data in quantitative variables. Through analysis of both asymmetric and non-normal simulated and real data, we demonstrate that the two-stage imputation method outperforms imputation methods lacking variable selection, as evidenced by accuracy measures. During the analysis of real survey data, we also demonstrate that our suggested two-stage imputation method surpasses the current imputation approach in terms of accuracy.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.4
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• pp.450-456
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• 2010

In the high-speed packet service, next generation mobile communication system has emerged as a major feature. If the fire of these high-speed kit services and non-continuous transmission of data due to the symmetrical nature of daeyiteo traffic for D-CDMA system has been actively studied. Small amounts of data moving in the uplink, but the real-time video downlink transmission, such as downloading large files to move data and services to those with asymmetric traffic characteristics, a system that can efficiently handle the data requirements be. Of 3GPP TDD(Time Division Duplex) scheme based on CDMA and TDMA in a way by introducing the concept through the proper allocation of time slots that can handle asymmetric traffic efficiently, has an advantage. TD-CDMA system by considering the characteristics of the frame configuration of transmission methods, such as physical channel structure and channel coding has been investigated. In addition, the HARQ scheme TD-CDMA system performance is analyzed by comparing them.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.269-276
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• 2004

There exist several types of distributed subscriber networks using Asymmetric Digital Subscriber Line(ADSL), Very high -bit rate Digital subscriber Line(VDSL), and Data Oner Cable Service Interface Specifications(DOCSIS). The efficient and concentrated network management of those several distributed subscribers networks and resources requires the general management information model of network, which has abstract and conceptual managed objects of the heterogeneous networks and its equipment to manage the integrated subscriber network. This paper presents the general Internet subscribers network modeling framework using RM-ODP to manage that network in the form of integrated hierarchy. This paper adopts the object-oriented development methodology with UML and designs and implements the HFC network of DOCSIS as an example of the subscriber network.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.6
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• pp.703-709
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• 2014

In the AMP(Asymmetric Multiprocessing) based dual core using core-specific operating system in a single processor system, shared memory method is used to send data between processors in dual core. To used shared memory in different operating systems, there is a problem of needing to solving the issue of message communication and synchronization between the two operations systems. In this paper, separate memory controller was used for data sharing between different processor cores in dual core environment. This controller can designate two slave ports to allow simultaneous access from two processors, and in the case of process data simultaneously by two processors, priority order of slave ports is determined through memory mediator. When sending data from A to B processor, SRAM area was logically separated into 8 pages. It allowed using memory area from multiple processes with the size of 4KByte per page, and control register with the size of 4Byte was used to discern the usability of current page.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1332-1339
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• 2000

This paper presents the architecture and design of a high speed asymmetric data transmission baseband MODEM ASIC chip for CATV networks. The implemented MODEM chip supports the physical layer of the DOCSIS(Data Over Cable Service Interface Specification) standard in MCNS(Multimedia Cable Network System) The chip consists of a QPSK/16-QAM transmitter and a 64/256-QAM receiver which contain a symbol timing recovery circuit, a carrier recovery circuit, a blind equalizer using MMA and LMS algorithms. The chip can support data rates of 64Mbps at 256 QAM and 48Mbps at 64-QAM and can provide symbol rates up to 8MBaud. This symbol rate is faster than existing QAM receivers. We have performed logic synthesis using the $0.35\mu\textrm{m}$ standard cell library. The total number of gates is about 290,000 and the implemented chip is being fabricated and will be delivered soon.