• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.2
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• pp.206-211
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• 2009

This paper presents a methodology to 1-day-forecast stock index using the automatic feature extraction method based on the neural network with weighted fuzzy membership functions (NEWFM). The distributed non-overlap area measurement method selects the minimized number of input features by automatically removing the worst input features one by one. CPP$_{n,m}$(Current Price Position of the day n: a percentage of the difference between the price of the day n and the moving average from the day n-1 to the day n-m) and the 2 wavelet transformed coefficients from the recent 32 days of CPP$_{n,m}$ are selected as minimized features using bounded sum of weighted fuzzy membership functions (BSWFMs). For the data sets, from 1989 to 1998, the proposed method shows that the forecast rate is 60.93%.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.2
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• pp.99-105
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• 2017

Type-2 fuzzy sets are preferred over type-1 sets as they are capable of addressing uncertainty more efficiently. The fuzzifier values play pivotal role in managing these uncertainties; still selecting appropriate value of fuzzifiers has been a tedious task. Generally, based on observation particular value of fuzzifier is chosen from a given range of values. In this paper we have tried to adaptively compute suitable fuzzifier values of interval type-2 possibilistic fuzzy c-means (IT2 PFCM) for a given data. Information is extracted from individual data points using histogram approach and this information is further processed to give us the two fuzzifier values $m_1$, $m_2$. These obtained values are bounded within some upper and lower bounds based on interval type-2 fuzzy sets.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.2
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• pp.171-175
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• 1986

Pectic substance of hot pepper crude cell wall was fractionated during ripening and softening. The pectic substance was divided ionically associated pectin(IAP) and covalently bounded pectin with hemicellulose(CBP). And then, the composition and the modification of the pectic substance using gel filtration chromatography were studied. The polyuronide associated with the CBP increased owing to decreasing of pectin bound hemicellulose linked to galactose by the turning stage showed softening. The molecular weight profiles of IAP shifted from low molecular weight profiles of IAP shifted from low molecular weight to high molecular weight polymers. While, the CBP changed from high molecular weight to low molecular weight polymers during ripening. It is suggested that the changes in the pectic substance associated with fruit softening should involve the alteration of CBP-bound hemicellulose like galactan.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.205-213
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• 2011

The Long Term Evolution (LTE) system is designed to provide a high quality data service for fast moving mobile users. It is based on the Orthogonal Frequency Division Multiplexing (OFDM) and relies its channel estimation on the training samples which are systematically built within the transmitting data. Either a preamble or a lattice type is used for the distribution of training samples and the latter suits better for the multipath fading channel environment whose channel frequency response (CFR) fluctuates rapidly with time. In the lattice-type structure, the estimation of the CFR makes use of the least squares estimate (LSE) for each pilot samples, followed by an interpolation both in time-and in frequency-domain to fill up the channel estimates for subcarriers corresponding to data samples. All interpolation schemes should rely on the pilot estimates only, and thus, their performances are bounded by the quality of pilot estimates. However, the additive noise give rise to high fluctuation on the pilot estimates, especially in a communication environment with low signal-to-noise ratio. These high fluctuations could be monitored in the alternating high values of the first forward differences (FFD) between pilot estimates. In this paper, we analyzed statistically those FFD values and propose a postprocessing algorithm to suppress high fluctuations in the noisy pilot estimates. The proposed method is based on a localized adaptive moving-average filtering. The performance of the proposed technique is verified on a multipath environment suggested on a 3GPP LTE specification. It is shown that the mean-squared error (MSE) between the actual CFR and pilot estimates could be reduced up to 68% from the noisy pilot estimates.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.5
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• pp.582-589
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• 2003

This paper presents the robust stability analysis and design methodology of the fuzzy feedback linearization control systems. Uncertainty and disturbances with known bounds are assumed to be included Un the Takagi-Sugeno (TS) fuzzy models representing the nonlinear plants. $L_2$ robust stability of the closed system is analyzed by casting the systems into the diagonal norm bounded linear differential inclusions (DNLDI) formulation. Based on the linear matrix inequality (LMI) optimization programming, a numerical method for finding the maximum stable ranges of the fuzzy feedback linearization control gains is also proposed. To verify the effectiveness of the proposed scheme, the robust stability analysis and control design examples are given.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.162-168
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• 2015

The purposes of this study are estimating willingness to pay (WTP) of forest owners for the disaster insurance premium for forest products in Korea and investigating factors affecting their WTP. The result with contingent valuation method shows that forest owners' median WTP is $9,440\;KRW/ha{\cdot}yr$. Advanced forest managers including devoted forest managers and forestry successors are willing to pay more for insurance premium compared to non-advanced ones, and those who have experienced disaster in their own forest land have higher WTP than others. WTP of advanced forest managers appears to be 50% higher than that of non-advanced. These results imply that policy makers should consider advanced forest managers as a priority to introduce the insurance system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.142-151
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• 2013

This study develops an automation system for metallic mold design that is applicable in forging non-axial symmetric parts. The metallic mold design program is used to design the metallic mold using two-dimensional axial symmetric metallic molds and to predict the stress concentration using finite element analyses. Then, the program redesigns the metallic mold using variables such as the optimal split diameter, maximum allowable inner pressure, fit tolerance, and stress distribution, which are calculated using the metallic mold design program. When the involute spur gear is forged, stress concentration occurs on the tooth root bounded at the symmetric surface. The SCM4 material is suitable for metallic molds because the stress is less than the yield strength of the insert and it acts on the tooth root regardless of the inner pressure. The metallic mold for forging non-axial symmetric parts can be designed through adjusting the magnitude of the contact pressure. The program developed in this study can be applied to metallic mold designs in involute spur gears of forging, which is an ordinary non-axial symmetric part.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.118.1-118.1
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• 2012

In situ observations from the Wind spacecraft that statistically analyzed the solar wind proton at 1 AU has indicated that the measured proton temperature anisotropies seems to be regulated by the oblique instabilities (the mirror and oblique firehose). This result is in contradiction with the prediction of linear kinetic theory that the ion-cyclotron (for ${\beta}_{\parallel}$ < 2) and parallel firehose (for ${\beta}_{\parallel}$ <10) would dominate over the oblique instabilities. Various kinds of physical mechanisms have been suggested to explain this disagreement between the observations and linear theory. All of the suggestions consider the solar wind as a unoform magnetized plasma. However the real space environment is replete with the intermediate spatio-temporal scale variations associated with various physical quantities, such as the magnetic field intensity and the solar wind density. In this paper we present that the pervasive intermediate-scale temporal variation of the local magnetic field intensity can lead to the modification of the proton temperature anisotropy versus beta inverse correlation for temperature-anisotropy-driven instabilities. By means of quasilinear kinetic theory involving such temporal variation, we construct the simulated solar wind proton data distribution associated the magnetic fluctuations in (${\beta}_{\parallel}$, $T_{\perp}/T_{\parallel}$) space. It is shown that the theoretically simulated proton distribution and a general trend of the enhanced fluctuations bounded by the oblique instabilities are consistent with in situ observations. Furthermore, the measure magnetic compressibility can be accounted for by the magnetic spectral signatures of the unstable modes.

• Journal of Korea Water Resources Association
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• v.45 no.1
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• pp.29-37
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• 2012

This paper attempts to measure the economic benefits of tap water quality improvement using a specific case study of Ulsan, one of the large cities in Korea. To this end, we apply the contingent valuation (CV) method by employing a one-and-one-half bounded spike dichotomous choice question format. We surveyed a randomly selected sample of 400 households in Ulsan and asked respondents questions in person-toperson interviews about how they would willing to pay for the program. Respondents overall accepted the contingent market and were willing to contribute a significant amount (1,611 won), on average, per household per month. This willingness varies according to individual characteristics such as education level and income. The aggregate value of the program in Ulsan amounts to approximately 8 billion won per year.

• Research in Community and Public Health Nursing
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• v.12 no.3
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• pp.705-715
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• 2001

This study examined 19 papers published from 1977 to 2000 based on the objective frame evaluation. This purpose of this study was to examine the trend of Hwabyung research and to serve as a guide for the future 'Hwabyung' study. The results of studies were as follow. In the design of research, clinical studies are definitely dominant. As for the fields of research, the concept of Hwabyung was studied more frequently than the others. As for the authorship. psychiatrists prevailed but nursing professionals are on the increase. Research subject in clinical and survey study, patient was definitely dominant and the place of study was almost always a hospital (75%), data collection was higher on interview (58.3%). Hwabyung was considered unique culture bounded syndrome related to Korean culture. Frequent etiologic factor of Hwabyung were a husband's extra-marital affair, conflicts between houses wives and mothers-in-laws, and financial loss and suffering. From the incidence of Hwabyung, a greater number of patients with Hwabyung were middle aged women in the low economic and educational classes, and these were connected with the culture and the family system. The symptoms of Hwabyung included psychological and physical symptom, neurological disorder and disease behavior. Defense mechanisms and coping strategies for Hwabyung were somatization, suppression, orality, withdrawal, isolation, regression, help-seeking, complaining, and wreaking anger. Treatment of Hwabyung were medication, effort by herself, communication with families, consultation with psychologist, acupuncture, negative therapy, moxa, and Qi-kong. Psychiatric therapy, behavior therapy, nursing intervention on multi-interdisciplinary approach and psychiatric nursing approach were recommended for the nursing care of a Hwabyung patient.