• Journal of KIISE:Databases
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• v.31 no.2
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• pp.91-98
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• 2004

DHP mining association rules algorithm maintains previously independent direct hash table to reduce the sire of hash tree containing the frequency number of each candidate large itemset. It performs pruning by using the direct hash table when the hash tree is constructed. The mort large the size of direct hash table increases, the higher the effort of pruning becomes. Especially, the effect of pruning in phase 2 which generate 2-large itemsets is so high that it dominates the overall performance of DHP algorithm. So, following the speedy trends of producing VLM(Very Large Memory) systems, extreme increment of direct hash table size is being tried and one of those trials is perfect hash table in phase 2. In case of using perfect hash table in phase 2, we found that some rearrangement of DHP algorithm got about 20% performance improvement compared to simply ｜H$_2$｜ reconfigured DHP algorithm. In this paper, we examine the feasibility of perfect hash table in phase 2 and propose PHP algorithm, a rearranged DHP algorithm, which uses the characteristics of perfect hash table sufficiently, then make an analysis on the results in experimental environment.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.480-485
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• 2015

Effects of dynamic high-pressure (DHP) treatments on microbial stability, vitamin C concentration, color, sugar content, color, and pH of strawberry juice were studied and compared with those of the conventional thermal treatment. Freshly prepared strawberry juice was thermally treated at $110^{\circ}C$ for 1 min or treated by DHP at 205 MPa and 20, 50, 60, or $70^{\circ}C$. The thermal treatment and the DHP treatments, both with and without integration with heating at $70^{\circ}C$, reduced the number of indigenous aerobic microorganisms by >6 log CFU/mL. Vitamin C concentration, color, and sugar content were higher in the DHP-treated juice than in the thermally treated juice, regardless of integration with heating. Compared to the thermal treatment, DHP treatments resulted in longer color retention and higher sugar contents in strawberry juice stored at $4^{\circ}C$ for 63 days. These results have demonstrated the potential use of DHP as a novel method for pasteurizing strawberry juice.

• Journal of Microbiology and Biotechnology
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• v.26 no.5
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• pp.823-828
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• 2016

The present study investigated the protective effect of naturally purified 4-(3,4-dihydroxyphenyl)-3-buten-2-one (DHP) from Phellinus linteus against naproxen-induced gastric antral ulcers in rats. To verify the protective effect of DHP on naproxen-induced gastric antral ulcers, various doses (1, 5, and 10 μg/kg) of DHP were pretreated for 3 days, and then gastric damage was caused by 80 mg/kg naproxen applied for 3 days. DHP prevented naproxen-induced gastric antral ulcers in a dose-dependent manner. In particular, 10 μg/kg DHP showed the best protective effect against naproxen-induced gastric antral ulcers. Moreover, DHP significantly attenuated the naproxen-induced lipid peroxide level in gastric mucosa and increased the activities of radical scavenging enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, in a dose-dependent manner. A histological examination clearly demonstrated that the gastric antral ulcer induced by naproxen nearly disappeared after the pretreatment of DHP. These results suggest that DHP can inhibit naproxen-induced gastric antral ulcers through prevention of lipid peroxidation and activation of radical scavenging enzymes.

• Archives of Pharmacal Research
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• v.14 no.3
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• pp.271-278
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• 1991

To investigate further whether the effects of the dihydropyridine (DHP) drugs on calcium channels are related to those of these drugs on muscarinic receptors, the binding characteristics of the DHP calcium channel agonist, Bay K 8644, on muscarinic receptors and calcium channels were compared to those of the DHP calcium channel antagonists, nicardipine and nimodipine in the dog cardiac sarcolemma. Bay K 8644, nicardipine and nimodipine inhibited the specific $[^3H]$QNB binding with $K_i$ values of 16.7\mu{M}$, 3.5\mu{M}$ and 15.5\mu{M}$ respectively. Saturation data of $[^3H]$QNB binding with $K_i$ VALUES OF 16.7\mu{M}$ 3.5\mu{M}$ and 15.5\mu{M}$ respectively. Saturation data of $[^3H]$QNB binding in the presence of these DHP drugs showed this inhibition to be competitive. Bay K 8644, like nicardipine and nimodipine, blocked the binding of $[^3H]$nitrendipine to the high affinity DHP binding sites, but atropine did not, indicating that the muscarinic receptors and the DHP binding sites m but atropine did not, indicating that the muscarinic receptors and the DHP bindings sites on calcium channels are distinct. The $K_i$ value of Bay K 8644 for the DHP binding sites was 4nM. Nicardipine and nimodipine $(K_i:0.1-0.2\;nM)$ were at least 20 times more potent than Bay K 8644 in inhibiting $[^3H]$ nitrendipine binding. Thus, the muscarinic receptors were about 4000 times less sensitive than thes high afinity DHP binding sites to Bay K 8644. These results suggest that the DHP calcium agonist Bay K 8644 binds directly to the muscarinic receptors but its interaction with the muscarinic receptors is not related to its binding to the DHP binding sites on calcium channels.

• Journal of the Korean Chemical Society
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• v.26 no.3
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• pp.172-178
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• 1982

A psoralen-DNA monoadduct analogue, 4',5'-dihydropsoralen (DHP) is synthesized and its photophysical properties such as fluorescence quantum yield (0.08), phosphorescence quantum yield (0.013), fluorescence lifetime (0.95ns), and phosphorescence lifetime(0.039s) were measured in ether solution and in frozen matrix state at 77K. The photocycloaddition reaction of DHP with tetramethylethylene(TME) was carried out in solution and in the frozen state. The major photoadduct was isolated and characterized by elemental analysis and physical methods such as UV, IR, NMR, and mass spectrometry. The major DHP-TME photoadduct was proved to be an 1 : 1 $C_4$-cycloadduct formed through 2 + 2 cycloaddition of the pyrone double bond of DHP to TME.

• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1323-1325
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• 2008

The acetylene black (AB) was dispersed into water in the presence of dihexadecyl hydrogen phosphate (DHP) via ultrasonication, resulting in a stable and well-distributed AB/DHP suspension. After evaporation of water, an AB/DHP composite film-modified electrode was prepared. The electrochemical responses of $K_3$[Fe$(CN)_6$] at the unmodified electrode, DHP film-modified electrode and AB/DHP film-modified electrode were investigated. It is found that the AB/DHP film-modified electrode possesses larger surface area and electron transfer rate constant. Furthermore, the electrochemical behaviors of 1-naphthylacetic acid (NAA) were examined. At the AB/DHP film-modified electrode, the oxidation peak current of NAA remarkably increases. Based on this, a sensitive and convenient electrochemical method was proposed for the determination of NAA. The linear range is in the range from $4.0 {\times} 10^{-8}\;to\;5.0 {\times} 10^{-6}$ mol $L^{-1}$, and the detection limit is $1.0 {\times} 10^{-8}$ mol $L^{-1}$. Finally, this new sensing method was employed to determine NAA in several soil samples.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.223-229
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• 2010

In this study diverse dehydrogenative polymers (DHPs) were synthesized with three precursors of native lignin [p-coumaryl alcohol (PCA), coniferyl alcohol (CA), sinapyl alcohol (SA)] in the presence of horseradish peroxidase (HRP, EC. 1.11.1.7)/$H_2O_2$. To compare the structural features between DHPs and native lignin, the DHPs as well as pine/poplar milled wood lignins were simultaneously subjected to gel permeation chromatography (GPC) to determine average molecular weights and derivatization followed by reductive cleavage (DFRC) to investigate the frequency of ${\beta}$-O-4 linkage. The highest yield of DHP was measured to 71% when CA was solely injected (G-DHP) and the yield of H-DHP was 42%. However, single injection of SA could not form any polymer in this system. The average molecular weights of DHPs were ranged between 3,000~4,700, which were only 1/2 fold compared with that of pine MWL (G-type lignin: Mw 7,340) and 1/3 scale compared with that of poplar MWL (GS-type lignin: Mw 13,250). DFRC analysis revealed that the formation of ${\beta}$-O-4 linkage during dehydrogenative polymerization was the highest in the GS-DHP with ca. 502 ${\mu}mol$/g, which was, however, remained to only 50% compared to that in poplar MWL (1107 ${\mu}mol$/g). The ${\beta}$-O-4 linkage was estimated to ca. 286 ${\mu}mol$/g In the G-DHP, which was twice as much as that of H-DHP(127 ${\mu}mol$/g). Similar to GS-DHP, only half amount of ${\beta}$-O-4 linkage, compared to pine MWL, was formed during in vitro polymerization of CA by horseradish peroxidase/$H_2O_2$.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.81-92
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• 2021

The purpose of this study is to present an approach to the "Digital Health Passport" (DHP), which will be the most important in the change of the travel industry among the sudden environmental changes brought about by COVID-19. To this end, this study reviewed a variety of empirical literature on DHP, and proposed a framework for DHP based on literature review. The framework is composed of travel intention, health information provision intention, and new technology acceptance/adoption of tourists. First, in terms of travel intention, providing information to DHP should not undermine the travel intention of the travelers. It should be possible to facilitate the travelers' enjoyment by using the information provided by the traveler. In addition, there is a need to assure that the data provided by travelers is managed in a reliable way. Second, it is necessary to understand why the travelers want to provide additional personal information (information disclosure), rather than seeing healthcare information only in terms of mandatory information provision. Finally, from the perspective of new technology, it is necessary to understand the intention of travelers to use/adopt DHP. The key implication of this work is that it proposed a DHP framework for realizing the travel bubble to predict and respond to foreign travelers' behaviors.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.615-621
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• 1997

Dehydropeptidase-I (DHP-I) was solubilized from porcine kidney by treatment with n-butanol and partially purified 19.25 fold by $(NH_4)_2SO_4$ precipitation, DEAE-Sepharose CL-6B ion exchange chromatography and Sephacryl S-300 HR chromatography with an overall yield of 19.16. DHP-I showed its optimal activity at pH 7.5 and 25$^{\circ}C$. Its activity was stable under neutral and alkaline conditions, but was disappeared under acidic condition. And DHP-I was heat-labile and its activity remained at 45$^{\circ}C$ for 3hrs. The enzyme was not inhibited by dicationic ions, while its activity was increased by $Co^{2+}$(1mM) and $Zn^{2+}$ (0.1mM). The enzyme was inhibited by EDTA and N-ethylmaleimide. The relative molecular mass of DHP-I was estimated to be approximately 100kDa by gel filtration chromatography. The $K_m$ value of DHP-I for glycyldehydrophenylalanine (GDHP) was 1.98mM. DWP20418 [(1R, 5S, 6S)-6-[1-(R)-Hydroxyethyl]-1-methyl-2-[(2S, 4S)-2-(piperazinylcarbonyl)-1-(R)-hydroxyethyl)pyrrolidine-4-thio]carbapen-2-em-3-carboxylic acid], compared with meropenem (MEPM), was rather easily hydrolized by DHP-I, while it was four times more resistant than imipenem (IPM) to DHP-I.

• The KIPS Transactions:PartD
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• v.13D no.5 s.108
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• pp.651-660
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• 2006

Algorithms for mining association rules based on the Apriori algorithm use the hash tree data structure for storing and counting supports of the candidate frequent itemsets and the most part of the execution time is consumed for searching in the hash tree. The DHP(Direct Hashing and Pruning) algorithm makes efforts to reduce the number of the candidate frequent itemsets to save searching time in the hash tree. For this purpose, the DHP algorithm does preparative simple counting supports of the candidate frequent itemsets. At this time, the DHP algorithm uses the direct hash table to reduce the overhead of the preparative counting supports. This paper proposes and evaluates an efficient hashing mechanism for the direct hash table $H_2$ which is for pruning in phase 2 and the hash tree $C_k$, which is for counting supports of the candidate frequent itemsets in all phases. The results showed that the performance improvement due to the proposed hashing mechanism was 82.2% on the maximum and 18.5% on the average compared to the conventional method using a simple mod operation.