• Journal of the Korean Mathematical Society
• /
• v.49 no.3
• /
• pp.623-639
• /
• 2012

The convex cone $\mathbb{V}_1$ generated by separable states is contained in the cone $\mathbb{T}$ of all positive semi-definite block matrices whose block transposes are also positive semi-definite. We characterize faces of the cone $\mathbb{V}_1$ induced by faces of the cone $\mathbb{T}$ which are determined by pairs of subspaces of matrices.

• Communications of the Korean Mathematical Society
• /
• v.18 no.1
• /
• pp.133-149
• /
• 2003

Local stability of steady states of an epidemic model is considered. An age structured S-I-R epidemic model with separable inter-cohort force of infection with external force is considered. Stability result for the nontrivial steady states is obtained.

• Journal of the Korean Physical Society
• /
• v.73 no.10
• /
• pp.1420-1430
• /
• 2018

We investigate an entangled system, which is analogous to a composite system of a black hole and Hawking radiation. If Hawking radiation is well approximated by an outgoing particle generated from pair creation around the black hole, such a pair creation increases the total number of states. There should be a unitary mechanism to reduce the number of states inside the horizon for black hole evaporation. Because the infalling antiparticle has negative energy, as long as the infalling antiparticle finds its partner such that the two particles form a separable state, one can trace out such a zero energy system by maintaining unitarity. In this paper, based on some toy model calculations, we show that such a unitary tracing-out process is only possible before the Page time while it is impossible after the Page time. Hence, after the Page time, if we assume that the process is unitary and the Hawking pair forms a separable state, the internal number of states will monotonically increase, which is supported by the Almheiri-Marolf-Polchinski-Sully (AMPS) argument. In addition, the Hawking particles cannot generate randomness of the entire system; hence, the entanglement entropy cannot reach its maximum. Based on these results, we modify the correct form of the Page curve for the remnant picture. The most important conclusion is this: if we assume unitarity, semi-classical quantum field theory, and general relativity, then the black hole should violate the Bekenstein-Hawking entropy bound around the Page time at the latest; hence, the infinite production arguments for remnants might be applied for semi-classical black holes, which seems very problematic.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.233-236
• /
• 1996

This paper describes a liner state-space model for a flexible stick balencer. The method employed to generate the model utilizes a separable formulation of assumed modes to represents the transverse displacement due to bending Lagrangian dynamics are applied to determine the kinetic and potential energies for the system. The resultant dynamic equations are then organized into a state space model and linearized using Taylor series expansion method. A minimum order observer is designed to estimate unmeasurable states.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.6
• /
• pp.578-585
• /
• 2003

The chum salmon (Oncorhynchus keta) is an anadromous fish distributed all around the North Pacific. Artificial production and release of the juveniles are being made by Korea, Japan, Russia, Canada and the United States. It is important to set up some criteria identifying each stock in order to clarify each nation's right of harvest for the chum salmon resource. As an attempt to build such criteria, we analyzed sequences of a microsatellite DNA Ogo5 and the COIII-ND3-ND4L region of the mitochondrial DNA from chum salmons of Korea, Japan, and the United States. Ogo5 has 4 different alleles: allele A, B-1, B-2, and B-3. Allele B-3 is found only in 3 individuals out of 12 Korea salmons. The Japan salmons have the other 3 alleles and the America salmons have only 2 allots, A and B-1. Heterozygosity index (Ho/He) distinguishes the Korea (1.61) and Japan salmons (1.63) from the America ones (1.09). Seventeen different haplotypes are found in the COIII-ND3-ND4L region from 60 individuals,20 from each stock. The gene genealogy of the haplotypes revealed by TCS program shows that the Korea and Japan salmons are genetically closely linked, but that they are clearly distinguished from the America ones. Ten and eleven individuals of the Korea and Japan salmons have an identical haplotype. Nine individuals of the Korea salmons $(45\%),$ however, are separable from the Japan salmons by their own specific nucleotides. This result presents usefulness of the COIII-ND3-ND4L region as a genetic marker for identification of the chum salmon stocks.

• Journal of Arbitration Studies
• /
• v.27 no.4
• /
• pp.91-113
• /
• 2017

UN Convention on International Sale of Goods (CISG) and International Commercial Arbitration aim at the promotion and facilitation of international trade. Both of them share similar general principles; i.e., party autonomy and pacta sunt servanda. Also they are often applied concurrently in the case of the international commercial trade. The purpose of this article is to investigate whether the CISG could apply the formation of the arbitration clause that is included in the main contract governed by CISG. Sellers and buyers have freedom of designating choice of law that is applied to their contracts. An international arbitration agreement is presumed to be separable from the contract in which it is found. However, arbitration clauses commonly form part of a general contract. Thus, the CISG is intended to be applied to dispute resolution clauses, including arbitration clause even if it is not completely suitable. Notably, there is a fundamental distinction between the CISG and arbitration. The CISG abolished the formalities of contract. New York convention requires Contracting States' Courts to enforce written international agreements to arbitrate.

• The Korean Journal of Physiology and Pharmacology
• /
• v.18 no.6
• /
• pp.517-524
• /
• 2014

Phasic and tonic ${\gamma}$-aminobutyric acidA ($GABA_A$) receptor-mediated inhibition critically regulate neuronal information processing. As these two inhibitory modalities have distinctive features in their receptor composition, subcellular localization of receptors, and the timing of receptor activation, it has been thought that they might exert distinct roles, if not completely separable, in the regulation of neuronal function. Inhibition should be maintained and regulated depending on changes in network activity, since maintenance of excitation-inhibition balance is essential for proper functioning of the nervous system. In the present study, we investigated how phasic and tonic inhibition are maintained and regulated by different signaling cascades. Inhibitory postsynaptic currents were measured as either electrically evoked events or spontaneous events to investigate regulation of phasic inhibition in layer 2/3 pyramidal neurons of the rat visual cortex. Tonic inhibition was assessed as changes in holding currents by the application of the $GABA_A$ receptor blocker bicuculline. Basal tone of phasic inhibition was maintained by intracellular $Ca^{2+}$ and $Ca^{2+}$/calmodulin-dependent protein kinase II (CaMKII). However, maintenance of tonic inhibition relied on protein kinase A activity. Depolarization of membrane potential (5 min of 0 mV holding) potentiated phasic inhibition via $Ca^{2+}$ and CaMKII but tonic inhibition was not affected. Thus, phasic and tonic inhibition seem to be independently maintained and regulated by different signaling cascades in the same cell. These results suggest that neuromodulatory signals might differentially regulate phasic and tonic inhibition in response to changes in brain states.

• Journal of KIISE:Databases
• /
• v.31 no.4
• /
• pp.395-408
• /
• 2004

A conjunctive Boolean text query refers to a query that searches for tort documents containing all of the specified keywords, and is the most frequently used query form in information retrieval systems. Typically, the query specifies a long list of keywords for better precision, and in this case, the order of keyword processing has a significant impact on the query speed. Currently known approaches to this ordering are based on heuristics and, therefore, cannot guarantee an optimal ordering. We can use a systematic approach by leveraging a database query processing algorithm like the dynamic programming, but it is not suitable for a text query with a typically long list of keywords because of the algorithm's exponential run-time (Ο(n2$^{n-1}$)) for n keywords. Considering these problems, we propose a new approach based on a property called the join sequence separability. This property states that the optimal join sequence is separable into two subsequences of different join methods under a certain condition on the joined relations, and this property enables us to find a globally optimal join sequence in Ο(n2$^{n-1}$). In this paper we describe the property formally, present an optimization algorithm based on the property, prove that the algorithm finds an optimal join sequence, and validate our approach through simulation using an analytic cost model. Comparison with the heuristic text query optimization approaches shows a maximum of 100 times faster query processing, and comparison with the dynamic programming approach shows exponentially faster query optimization (e.g., 600 times for a 10-keyword query).