• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권9호
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• pp.3298-3321
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• 2021

A lot of data hiding schemes have been proposed to embed secret data in the plain cover images or compressed images of various formats, including JPEG, AMBTC, VQ, etc. In this paper, we propose a production process of mosaic images based on three regular images of coffee beans. A primary image is first mimicked by the process to produce a mosaic cover image. A two-layer steganography is applied to hide secret data in the mosaic image. Based on the low visual quality of the mosaic cover image, its PSNR value can be improved about 1.5 dB after embedding 3 bpp. This is achieved by leveraging the newly proposed polarized search mask and the concepts of strong embedding and weak embedding. Applying steganography to the mosaic cover images is a completely new idea and it is promising.

• Journal of applied mathematics & informatics
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• 제41권2호
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• pp.413-437
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• 2023

In this paper, we introduce the concepts of (inf, sup)-hesitant fuzzy subsemigroups and (inf, sup)-hesitant fuzzy (generalized) bi-ideals of semigroups, and investigate their properties. The concepts are established in terms of sets, fuzzy sets, negative fuzzy sets, interval-valued fuzzy sets, Pythagorean fuzzy sets, hesitant fuzzy sets, and bipolar fuzzy sets. Moreover, some characterizations of bi-ideals, fuzzy bi-ideals, anti-fuzzy bi-ideals, negative fuzzy bi-ideals, Pythagorean fuzzy bi-ideals, and bipolar fuzzy bi-ideals of semigroups are given in terms of the (inf, sup)-type of hesitant fuzzy sets. Also, we characterize a semigroup which is completely regular, a group and a semilattice of groups by (inf, sup)-hesitant fuzzy bi-ideals.

• 한국식생활문화학회지
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• 제5권4호
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• pp.415-423
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• 1990

'The Joobang' is a cooking book written purely in Korean which came from a Mr. Lee. It is unknown when and by whom this book was written, but it is inferred from red pepper mentioned in this book and from Korean-writting type that the book was written around in the mid-nineteenth century. The contents of 'the Joobang' consist of thirty seven items in all : sixteen items of rice alcoholics, five side dishes, eleven Tucks(rice cakes) and Guaja(cookies) and five processed materials. Cereals for making rice alcoholics were regular rice and sticky rice. In the first brew, rice alcoholics is made all from regular rice, and in the second brew, fifty six percent of regular rice and forty four percent of sticky rice was made use of. For five items of alcoholics forming 31.3% of alcoholics, flour was added, in which case the proportion of leaven to cereals was lower. There were four types of processing cereals in brewing rice alcoholics Jee-ae-bop(steamed rice, 60.9%), thick gruel with cereals ground and completely cooked(8.7%), thick gruel with cereals ground and half cooked (26.1%) and GooMung Tuck(doughnut-shaped rice cake, 4.3%). The comparison of the materials for brewing rice alcoholics and of the types of processing cereals presented in the seven cooking books purely in Korean(Umsik Deemeebang, JoobangMoon, Umsikbo, Sool-mandununbop, Kyuhap chongseo. The Kims' Joobangmoon and The Lee's Umsikbup) showed us the following facts ; Yihwajoo (rice alcoholics brewed around the blooming time of pear trees) and Kwahajoo(rice alcoholics which passed the summed time) were most often introduced and commonest, and the materials for brewing and the types of processing little changed over times. The materials for side dishes were all animal food, and vegetable food was little used for side dishes. Red pepper was used for seasoning. It is a problem of Korean traditional cooking that there were no units of measuring for side dishes. The main materials for Tuck(rice cakes) and Guaja(cookies) were sticky rice, regular rice and honey. There was a variety of terms for the process, from which we can see that the procedures of making Tuck(rice cakes) and Guaja(cookies) were very complicate. Processed materials were chiefly made of sticky rice and the material of firewood(oak trees) and the strength of fire(fire burning vigorously and fire turning to ashes) were described.

• 한국초전도ㆍ저온공학회논문지
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• 제3권1호
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• pp.64-68
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• 2001

An experimental study on the Joule-Thomson cryocooler with the mixed refrigerant (MR) is described in this paper, J-T refrigeration experiment was performed with a single stage regular air-conditioning compressor The mixed refrigerant in the experiment was composed of 75% mol fraction of $N_2$. 30% moi fraction of CH$_4$. 30% moi fraction of $C_2$H$_{6}$. 10% mot fraction of $C_3$H$_{8}$ and 15% mot fraction of iso-C$_4$H$_{10}$. Oil mist in the MR stream could be eliminated completely by the glass microfiber filter. Since a single stage compressor that had been designed thor R22 is not appropriate for high Pressure ratio of the mixed refrigerant especially during the transient period. two modifications were incorporated to regular J-T refrigeration cycle. First. a Portion of the MR was by-passed at the inlet of the heat exchanger and transferred directly to 7he suction of the compressor in the modified system. Second, a buffer volume was Prepared to change the mass flow rate of refrigerant. The pressure ratio in J-T expansion device was relieved at the beginning of the operation due to the by-Pass scheme. but it gradually decreased during the transient Process as some of the MR component condensed at low temperature. The buffer volume at the suction side was used to increase the MR gas density in the system after the transient cool-down period. Form the experiment with the modified system, the refrigerator could reach the lowest temperature of -152$^{\circ}C$ without cooling load. and about -15$0^{\circ}C$ with 5 W of cooling load . . . .

• Smart Structures and Systems
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• 제18권6호
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• pp.1217-1231
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• 2016

In this research, a slotted patch antenna sensor is designed for wireless strain and crack sensing. An off-the-shelf RFID (radiofrequency identification) chip is adopted in the antenna sensor design for signal modulation. The operation power of the RFID chip is captured from wireless reader interrogation signal, so the sensor operation is completely battery-free (passive) and wireless. For strain and crack sensing of a structure, the antenna sensor is bonded on the structure surface like a regular strain gage. Since the antenna resonance frequency is directly related with antenna dimension, which deforms when strain occurs on the structural surface, the deformation/strain can be correlated with antenna resonance frequency shift measured by an RFID reader. The slotted patch antenna sensor performance is first evaluated through mechanics-electromagnetics coupled simulation. Extensive experiments are then conducted to validate the antenna sensor performance, including tensile and compressive strain sensing, wireless interrogation range, and fatigue crack sensing.

• 대한음성학회:학술대회논문집
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• 대한음성학회 1996년도 2월 학술대회지
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• pp.79-84
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• 1996

The two existing romanization systems in Korea, namely the recently promulgated Ministry of Education version sponsored by the National Academy of Sciences incorporating for the most part the McCune-Reischauer system and the Hangeul Haghoe or the Korean Language Society's version, must be judged as failures: He fennel for its disregard of Korean orthography and pronunciation, use of Latin-oriented pronunciation despite its assertion that English is the standard used, and the greatest weakness of all, its use of phonetic symbols neither found in regular typewriters, teleprinters, word processors and telex machines nor understood by laymen, sometimes not even by specialists. And the latter suffers from its undue emphasis on Korean orthography, Latin-oriented pronunciation being only partly capable of representing Korean pronunciation, among other shortcomings. Since the two existing romanization systems of Korean in South Korea, and romanization system of Japanese with Latin-oriented pronunciation are woefully inadequate, in today's world where English is used as if it were the international language almost all over the world, the present writer has invented a completely new system of romanizing Korean and Japanese by the so-called pseudo-phonetic method. This method employs the roman letters only and uses thorn in place of phonetic symbols as long as the letters thus applied are believed to have constant sound value. The English pronunciation is the standard used for this system.

• Journal of the Korean Statistical Society
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• 제30권2호
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• pp.179-192
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• 2001

When a statistical model has a hierarchical structure such as multilayer perceptrons in neural networks or Gaussian mixture density representation, the model includes distribution with unidentifiable parameters when the structure becomes redundant. Since the exact structure is unknown, we need to carry out statistical estimation or learning of parameters in such a model. From the geometrical point of view, distributions specified by unidentifiable parameters become a singular point in the parameter space. The problem has been remarked in many statistical models, and strange behaviors of the likelihood ratio statistics, when the null hypothesis is at a singular point, have been analyzed so far. The present paper studies asymptotic behaviors of the maximum likelihood estimator and the Bayesian predictive estimator, by using a simple cone model, and show that they are completely different from regular statistical models where the Cramer-Rao paradigm holds. At singularities, the Fisher information metric degenerates, implying that the cramer-Rao paradigm does no more hold, and that he classical model selection theory such as AIC and MDL cannot be applied. This paper is a first step to establish a new theory for analyzing the accuracy of estimation or learning at around singularities.

• 대한수학회지
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• 제45권5호
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• pp.1443-1482
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• 2008

In this paper we define a Myller configuration in a Finsler space and use some special configurations to obtain results about Finsler subspaces. Let $F^{n}$ = (M,F) be a Finsler space, with M a real, differentiable manifold of dimension n. Using the pull back bundle $({\pi}^{*}TM,\tilde{\pi},\widetilde{TM})$ of the tangent bundle $(TM,{\pi},M)$ by the mapping $\tilde{\pi}={\pi}/TM$ and the Cartan Finsler connection of a Finsler space, we obtain an orthonormal frame of sections of ${\pi}^{*}TM$ along a regular curve in $\widetilde{TM}$ and a system of invariants, geometrically associated to the Myller configuration. The fundamental equations are written in a very simple form and we prove a fundamental theorem. Important lines in a Finsler subspace are defined like special lines in a Myller configuration, geometrically associated to the subspace: auto parallels, lines of curvature, asymptotes. Torse forming vector fields with respect to the Cartan Finsler connection are characterized by means of the invariants of the Frenet frame of a versor field along a curve, and the new notion of torse forming vector fields in the sense of Myller is introduced. The particular cases of concurrence and parallelism in the sense of Myller are completely studied, for vector fields from the distribution $T^m$ of the Myller configuration and also from the normal distribution $T^p$.

• Journal of Periodontal and Implant Science
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• 제39권4호
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• pp.425-429
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• 2009

Purpose: The palatogingival groove is a developmental anomaly of the incisor teeth, which often presents severe localized periodontal disease. The purpose of this study was to evaluate the clinical outcome of palatogingival groove-associated periodontal lesion following flap operation with glass ionomer filling. Methods: Four patients with periodontal lesion associated with the palatogingival groove were chosen for this case study. Clinical indices were taken and radiographic exam was performed at the baseline of the study and four patients were treated by flap operation with GI filling. Post-surgical visits were scheduled at regular intervals to check clinical and radiographic changes. Results: Symptoms and signs of periodontal lesion were almost completely resolved with improvement of periodontal indices. Conclusions: Flap operation with direct glass ionomer restoration is thought to be an acceptable method which can produce favorable results in the treatment of periodontal lesion caused by palatogingival groove on the maxillary lateral incisor.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.309-314
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• 2009

New poly(arylene-ethynylene)s with silicon-containing ferrocene moiety in the polymer main chain were synthesized via the C-C bond forming reactions of 1,1´-bis(ethynyldimethylsilyl)ferrocene and various aromatic dihalides in high yields. The aromatic dihalides include 1,4-dibromobenzene, 4,4´-dibromobiphenyl, 9,10-dibromoanthracene, 2,5-dibromopyridine, 2,5-dibromothiophene, and 2,6-diiodo-4-nitroaniline. The polymer structures and properties were characterized by such instrumental methods as NMR $(^1H-,\;^{13}C-,\;and\;^{29}Si-)$, IR, UV-visible spectroscopies and TGA/DSC. The spectral data indicated that the present polymers have the regular alternating structure of 1,1´-bis(ethynyldimethylsilyl)ferrocenylene and arylene units. The resulting polymers were completely soluble in such organic solvents as methylene chloride, chloroform, benzene, chlorobenzene, and THF. The thermal behaviors of the resulting polymers were examined.