• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.2
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• pp.51-58
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• 1993

This paper describes the development of a speaker-dependent isolated word recognizer as applied to voice dialing in a car noise environment. for this purpose, several methods to improve performance under such condition are evaluated using database collected in a small car moving at 100km/h The main features of the recognizer are as follow: The endpoint detection error can be reduced by using the magnitude of the signal which is inverse filtered by the AR model of the background noise, and it can be compensated by using variants of the DTW algorithm. To remove the noise, an autocorrelation subtraction method is used with the constraint that residual energy obtainable by linear predictive analysis should be positive. By using the noise rubust distance measure, distortion of the feature vector is minimized. The speech recognizer is implemented using the Motorola DSP56001(24-bit general purpose digital signal processor). The recognition database is composed of 50 Korean names spoken by 3 male speakers. The recognition error rate of the system is reduced to 4.3% using a single reference pattern for each word and 1.5% using 2 reference patterns for each word.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2001.05a
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• pp.64-76
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• 2001

In this paper, A simple image hologram encryption and decryption technique based on the principle of interference are proposed. The technique using the photorefractive material for getting a stable interference pattern is also proposed. And combine these two techniques, I would like to implement a stable optical information security system. In the encrypting process, I would generate binary phase hologram which can reconstruct original image perfectly, and regard this hologram as original image to be encrypted image. And then the hologram is encrypted as randomly generated binary phase image. Reference image is also generated from the encrypted image by applying interference rule. In the decrypting process, I can get a interference intensity by interfering the reference image and the encrypted image in the interferometer. and transform inferference intensity information into phase information. I recover original image by inverse Fourier transforming the phase information. In this process, the intensity information generated by interference of two images is very sensitive to external vibrations. So, I would like to get a stable interference using the characteristic of SPPCM(self pumped phase conjugate mirror) in photorefractive materials, especially BaTiO₃.

• Ocean and Polar Research
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• v.21 no.2
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• pp.87-97
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• 1999

To estimate absolute transports by advection in the southwestern East Sea (Japan Sea), an inverse method was applied to CTD data obtained in July 1993. The relative velocities are calculated using the thermal wind equation. The inverse model was formulated to obtain a reference velocity based on the mass conservation in each of four vertical layers within a region enclosed by hydrographic sections and the coastal boundary. The flow patterns in the surface layer are clockwise and anti-clockwise in the regions south and northwest of Ulleung Island, respectively, and a strong northward flow appears in between them. In the second layer, the flow fields are generally weak. The inverse calculation yields the southward flow along the coast, and this suggests that the subsurface low salinity water in the Ulleung Basin is supplied by the southward transport along the east coast of Korea.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.777-778
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• 2006

In this thesis, we design and implement a Flash Cache Core Module (FCCM) which operates on the YAFFS NAND flash memory. The FCCM applies memory replacement policy and prefetching policy based on the page reference pattern of applications. Also, implement the Clean-First memory replacement technique considering the characteristics of flash memory. In this method the decision is made according to page hit to apply prefetched waiting area. The FCCM decrease I/O hit frequency up to 37%, Compared with the linux cache and prefetching policy. Also, it operated using less memory for prefetching(maximum 24% and average 16%) compared with the linux kernel.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.12
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• pp.75-82
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• 1998

Many multiplexing techniques are proposed for high storage densities in a volume hologram. In this paper, we present a hybrid angularly and spatially multiplexed volume holographic memory system. Multiple holograms are recorded by using reference and object waves with different incident angles and positions that are changed by step motors. A hologram is written by exposing the crystal with recording time schedule to the interference pattern of the object beam and a reference plane wave. Finally, we show experimental results of the storage of three layers of 300 multiplexed holograms in a LiNbO$_3$ : Fe crystal.

• The Journal of the Acoustical Society of Korea
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• v.3 no.2
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• pp.13-22
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• 1984

A surface acoustic wave signal processing device using the silicon surface state is presented and shown capable of storing a reference signal and later correlating another signal with the stored reference. The device memory consists of the storage of the spatial 2k pattern of an acoustic wave as stored charges in the surface state of silicon surface. Results of experiments are presented which characterize the operation of device. Simpliied models for charging process and nonlinear acoustoelectric interactions based on consideration of single surface state at the surface of silicon The validity of simplified model has been qualitatibely confirmed with experimental results and the application of this device to aprogrammable matched filter of communication is considered.

• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.35-42
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• 2022

This paper presents a stochastic model predictive control (SMPC) for stop maneuver of autonomous vehicles considering perception uncertainty of stopped vehicle. The vehicle longitudinal motion should achieve both driving comfortability and safety. The comfortable stop maneuver can be performed by mimicking acceleration profile of human driving pattern. In order to implement human-like stop motion, we propose a reference safe inter-distance and velocity model for the longitudinal control system. The SMPC is used to track the reference model which contains the position uncertainty of preceding vehicle as a chance constraint. We conduct simulation studies of deceleration scenarios against stopped vehicle in urban environment. The test results show that proposed SMPC can execute comfortable stop maneuver and guarantee safety simultaneously.

• Korean Journal of Community Nutrition
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• v.22 no.4
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• pp.279-288
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• 2017

Objectives: Recommended Menu (RM) prepared according to the Target Pattern expected to meet the dietary reference intake (DRI) of nutrients. Nutritional adequacy of RM in 'DRI for Koreans 2015' were analyzed to verify whether such expectation was fulfilled. Methods: Dishes in RM are categorized by 5 food groups, and number and types of dishes for main meal and between-meals were analyzed. The energy and 12 nutrients (protein, dietary fiber, Ca, P, Fe, Na, K, vitamin A, thiamin, riboflavin, niacin and vitamin C) contents in 10 RMs were calculated using the food composition table (CD) in 'DRI for Koreans'. Energy, energy contribution ratio, and nutrient contents in 10 RMs for 18 age groups were evaluated based on the 'DRI for Koreans 2015'. Results: Number of dishes per meal were 4.83, and representative table setting consisted of cooked rice + soup (or stew) +3 side dishes. Energy contents of RM were 75~109% of estimated energy requirement (EER). None of the RM met the DRI of all 12 nutrients examined. Calcium was the most insufficient nutrient. Only 1-2 years' RM met the DRI, all the other RMs did not meet the calcium DRI. Dietary fiber and potassium contents were also insufficient in most RM. In adult male's RM, only 1 nutrient, i.e. calcium did not meet the DRI, but in female adult's RM, 5~6 nutrients did not meet the DRI. Energy contribution ratio of carbohydrate, protein, and fat in RM were 59.0~70.4%, 15.7~17.5%, 12.1~23.5%, respectively. And 4 RMs out of 10 exceeded the upper limit of acceptable macro-nutrient distribution range (AMDR) of carbohydrate and 3 RMs out of 10 RM were below the lower limit of fat AMDR. Contribution ratio of nutrients were ${\geq}40%$ by food groups were as follows: grain group in energy and carbohydrate; meat fish egg legume group in fat, protein, and niacin; vegetables group in dietary fiber, vitamin A, and vitamin C; milk dairy products group in calcium. Conclusions: RM prepared according to the Target Pattern did not meet nutritional adequacy as expected. Especially calcium, potassium, and dietary fiber contents are needed to be increased in many RMs. Further, energy content in RM needs to be adjusted for fat sugar food group assigned in Target Pattern and condiment.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.1
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• pp.15-22
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• 2017

With the advance of Internet Technology, various social network services are created and used by users. Especially, the use of smart devices makes that multimedia contents can be used and distributed on social network services. However, since the crime rate also is increased by users with illegal purposes, there are needs to protect contents and block illegal usage of contents with multimedia forensics. In this paper, we propose a multimedia forensic technique which is identifying the video source. First, the scheme to acquire the sensor pattern noise (SPN) using morphology filtering is presented, which comes from the imperfection of photon detector. Using this scheme, the SPN of reference videos from the reference device is estimated and the SPN of an unknown video is estimated. Then, the similarity between two SPNs is measured to identify whether the unknown video is acquired using the reference device. For the performance analysis of the proposed technique, 30 devices including DSLR camera, compact camera, camcorder, action cam and smart phone are tested and quantitatively analyzed. Based on the results, the proposed technique can achieve the 96% accuracy in identification.

• The KIPS Transactions:PartB
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• v.14B no.1 s.111
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• pp.13-22
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• 2007

In this paper, we propose an audience counting method in an auditorium based on pattern comparison. The previous counting methods based on object detection can't exactly count the audience in real time because auditorium has coarse illumination condition and so many audiences. Therefore, in this paper, we count the audience in an auditorium with fixed seats by the method which the pattern from each reference seat is compared to the pattern from each input seat. Especially, to overcome limitations based on either illumination or noise, two pattern comparison methods are efficiently employed and combined. One is based on the amplitude projection, and the other is based on Walsh-Hadamard Kernel. Walsh-Hadamard Kernel has the characteristic which complements amplitude projection. Therefore, we ran achieve the accurate counting in the presence of coarse illumination and noise. The experimental results show that our method performs well on sequences of images acquired in an auditorium. We also verify a realistic possibility for other applications applying our method to the parking positioning system.