• Journal of the Chungcheong Mathematical Society
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• v.21 no.3
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• pp.361-370
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• 2008

We consider the Hyers-Ulam type stability of the Cauchy, Jensen, Pexider, Pexider-Jensen differences: $$(0.1){\hspace{55}}C(u):=u{\circ}A-u{\circ}P_1-u{\circ}P_2,\\(0.2){\hspace{55}}J(u):=2u{\circ}\frac{A}{2}-u{\circ}P_1-u{\circ}P_2,\\(0.3){\hspace{18}}P(u,v,w):=u{\circ}A-v{\circ}P_1-w{\circ}P_2,\\(0.4)\;JP(u,v,w):=2u{\circ}\frac{A}{2}-v{\circ}P_1-w{\circ}P_2$$, with respect to bounded distributions.

• Journal of Korea Game Society
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• v.19 no.4
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• pp.77-84
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• 2019

Pay-to-Win (P2W) is a billing system that pays cash in-game and has a impact on results and it has been criticized by users. Research on the adolescent users and the effect of the P2W is insufficient. In this regard, this study compares the game billing in P2W and non-P2W based on self-esteem. As a result, systems showed the interaction effect on the game billing with the self-esteem. In the non-P2W, game billing increased when the self-esteem was high, whereas the billing increased rapidly as the self-esteem was low in the P2W.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.41-48
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• 1984

The soil bacterium Agrobacterium tumefaciens is a plant pathogen that cause3 crown gall tumors by infecting the wounded dicotyledonous plants and subsequent integration of bacterial DNA into plant nuclear DNA. Virulent A. tumefaciens strains harbor a large Ti (tumor-inducing) plasmid that carries genes essential for tumorigenesis. In the present study, 13 strains (Malus pumila Mill; $A_{1-3}$, Populus monilifera; $W_{1-6}$, Populus tomentiglandlosa; $P_{1-3}$ and Rosa species; $R_1$) of Agrobacterium isolated in korean crown gall tumors and plasmids were observed in 6 strains ($W_2$, $W_3$, $W_6$, $P_1$, $P_3$ and $A_2$). The test for crown gall tumor formation was resulted only in ATCC15955 and $KW_2$ strains inoculated into the stem of sun flower and the development was observed for 4 and 6 weeks after inoculation. Above two Ti plasmids (pTi) were purified by cesium chloride-ethidium bromide density gradient centrifugation and digested with restriction enzyme and fragments of pTiATCC 15955 and $pTiKW_2$ observed by EcoR I ; 25&27, Hind III; 23&21, BamH I ; each 20 and Hpa I ; 12&27, and sizes of pTiATCC15955 and and $pTiKW_2$ calculated as 200 and 87 kbases. Octopine was isolated from tumor tissue ($W_{1-6}$ and $P_{1-3}$) and these strains confirmed as octopine type.

• Bulletin of the Korean Mathematical Society
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• v.55 no.1
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• pp.115-137
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• 2018

Let $R_{u{^2},v^2,w^2,p}$ be a finite non chain ring ${\mathbb{F}}_p[u,v,w]{\langle}u^2,\;v^2,\;w^2,\;uv-vu,\;vw-wv,\;uw-wu{\rangle}$, where p is a prime number. This ring is a part of family of Frobenius rings. In this paper, we explore the structures of cyclic codes over the ring $R_{u{^2},v^2,w^2,p}$ of arbitrary length. We obtain a unique set of generators for these codes and also characterize free cyclic codes. We show that Gray images of cyclic codes are 8-quasicyclic binary linear codes of length 8n over ${\mathbb{F}}_p$. We also determine the rank and the Hamming distance for these codes. At last, we have given some examples.

• Bulletin of the Korean Mathematical Society
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• v.61 no.1
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• pp.229-246
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• 2024

We consider the delay differential equations $$b(z)w(z+1)+c(z)w(z-1)+a(z)\frac{w'(z)}{w^k(z)}=\frac{P(z, w(z))}{Q(z, w(z))}$$, where k ∈ {1, 2}, a(z), b(z) ≢ 0, c(z) ≢ 0 are rational functions, and P(z, w(z)) and Q(z, w(z)) are polynomials in w(z) with rational coefficients satisfying certain natural conditions regarding their roots. It is shown that if this equation has a non-rational meromorphic solution w with hyper-order ρ2(w) < 1, then either deg_w(P) = deg_w(Q) + 1 ≤ 3 or max{deg_w(P), deg_w(Q)} ≤ 1. In addition, it is shown that in the case max{deg_w(P), deg_w(Q)} = 0 the equations above can have such a solution, with an additional zero density requirement, only if the coefficients of the equation satisfy certain strict conditions.

• Toxicological Research
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• v.26 no.3
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• pp.171-175
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• 2010

The human genome contains approximately 13 orphan cytochrome P450 (P450, CYP) genes, of which the apparent function or substrate has not been identified. However, they seem to possess their own biological relevance in some tissues or developmental stages. Here, we characterized the heterologously expressed CYP2W1, an orphan P450 enzyme. The recombinant CYP2W1 protein containing a $6{\times}$(His)-tag at Nterminus has been expressed in Escherichia coli and purified. Expression level of CYP2W1 holoenzyme was around 500 nmol P450 holoenzyme per liter culture medium. The reduced CO difference spectrum of CYP2W1 showed a maximum absorption at 449 nm. CYP2W1 indicated the significant induction to bioactivate Trp-P-1, MeIQ, and IQ in E. coli DJ701 tester strain. However, the bioactivation of B[$\alpha$]P, and NNK by CYP2W1 was relatively low. The model structure of CYP2W1 suggested the characteristic P450 folds with the lengths and orientations of the individual secondary elements. The F-G loop is situated on the distal side of heme to accommodate the flexibility of active site of CYP2W1. These studies can provide useful information for the finding of its biological roles and structure-function relationships of an orphan CYP2W1 enzyme.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.211-221
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• 2006

Purpose The aims of this study were to evaluate micro-tensile bond strength of composite resin bonded to dentin following high-speed rotary handpiece preparation or Er:YAG laser preparation with two different adhesive systems and to assess the influence of different Er:YAG laser energies on the micro-tensile bond strength. Materials and Methods In this study, 40 third morlars were used. Flat dentin specimans were obtained and randomly assigned to eight groups. Dentin surfaces were prepared with one of four cutting types: carbide bur, Er:YAG laser (2 W, 3 W and 4 W) and conditioned with two bonding systems, Scotchbond Multipurpose Plus (SM), Clearfil SE bond (SE) and composite resin-build ups were created. After storage for 24 hours, each specimen was serially sectioned perpendicular to the bonded surface to produce more than thirty slabs in each group. Micro-tensile bond strength test was performed at a crosshead speed of 1.0 mm/min. Micro-tensile bond strengths (${\mu}TBS$) were expressed as means$\pm$SD. Data were submitted to statistical analysis using two-way ANOVA, one-way ANOVA, Student-Newman-Keuls' multiple comparison test and t-test. Results and Conclusion 1. Regardless of bonding systems, the ${\mu}TBS$ according to cutting types were from highest to lowest : 3 W, 2 W, Bur, and 4 W. In addition, there was no significant difference between Bur and 4 W (p<0.001). 2. Regardless of cutting types, SM showed significantly higher ${\mu}TBS$ than SE (p<0.001). 3. Bonding to dentin conditioned with SM resulted in higher ${\mu}TBS$ for 3 W compared to Bur, 2 W, and 4 W. There was no significant difference between 2 W and Bur (p<0.001). 4. Bonding to dentin conditioned with SE resulted in higher ${\mu}TBS$ for 3 W compared to 2 W, 4 W, and Bur. Bur exhibited significant lower ${\mu}TBS$ than all other cutting types. There were no significant differences between 3 W, 2 W and between 4 W and Bur (p<0.001). 5. The ${\mu}TBS$ of laser cutting groups were shown in order from highest to lowest: 3 W, 2 W and 4 W in two bonding systems. There was no significant difference between 2 W and 3 W in SE (p<0.001). : The ${\mu}TBS$ of composite resin bonded dentin was significantly affected by interaction between the cutting type and bonding system. In the range of 2 W-3 W, cavity preparation of the Er:YAG laser seems to supply good adhesion of composite resin restoration no less than bur preparation. In particular, if you want to use the self-etching system, including Clearfil SE bond for the purpose of a simplification of the bonding procedures and prevention of adverse effects by excessive etching, an Er:YAG laser may offer better adhesion than a bur.

• KSBB Journal
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• v.9 no.4
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• pp.436-442
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• 1994

The production of itaconic acid by Aspergillus terreus NRRL 1960 was studied. The optimal culture conditional such as pH, inoculum size and medium composition were established. Maximum production of itaconic acid, $19.18g/\ell$, was obtained when the cultivation was carried out at $37^{\circ}C$ and pH 2.5 for 7days, with medium containing 5%(w/v) glucose, 0.5%(w/v) NH4Cl, 0.2%(w/v) yeast extract 0.1%(w/v) CaC12, 0.1%(w/v) MgSO4 and 0.2%(w/v) NaCl. A proper medium for inoculum culture was found to be 2%(w/v) malt extract. The batch production of itaconic acid with free cells in a stirredtank reactor was not efficient compared to the shake-flask culture.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.12 no.1
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• pp.37-43
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• 2006

PURPOSE: Previous studies have documented the lack of ultrasound's non-thermal effects on nerve conduction using frequencies of 1 MHz and 870 kHz. The purpose of this study was to determine the biophysical effects of continuous ultrasound on median local forearm temperature and motor nerve conduction velocities using frequencies of 3.0 MHz. SUBJECTS: Twelve healthy subjects (6 males, 6 females, age $22.30{\pm}2.41$ yrs, weight $61.33{\pm}10.16$ kg, height $167.58{\pm}8.04$ cm) without a history of neurological or musculoskeletal injury to their dominant arm volunteered for this study. METHODS AND MATERIALS: Each subject received a total of five treatments, one each at .0, 0.5, 1.0, 1.5, 2.0 W/$cm^2$ of 3 MHz continuous ultrasound on the anterior surface of the middle area of dominant forearm for 10 minutes. Dependent measures for forearm local temperature and median motor nerve conduction velocity (MNCV) were taken pretreatment and immediately post-treatment. One-way ANOVA were used for each dependent measure. RESULTS: The posttreatment forearm local temperature were differed significantly (p<0.001) between intensities of ultrasound. The posttreatment forearm local temperature of the ultrasound treated with 1.0 w/$cm^2$, 1.5 w/$cm^2$ and 2.0 w/$cm^2$ were significantly higher than 0.5 w/$cm^2$ and 0.0 w/$cm^2$ of ultrasound (p<0.05). The posttreatment median MNCV were differed significantly from the respective pretreatment velocities (p<0.001). The MNCV of the ultrasound treated with 0.0 w/$cm^2$ and 0.5 w/$cm^2$ were significantly (p<0.05) slower than that observed pretreatment, while the three ultrasound intensities produced significantly increased posttreatment MNCV: 1.0 w/$cm^2$ and 1.5 w/$cm^2$ and 2.0 W/$cm^2$. The posttreatment MNCV at 2.0 w/$cm^2$ and 1.5 w/$cm^2$ was significantly faster than that at 0 w/$cm^2$, 0.5 w/$cm^2$ and 1.0 w/$cm^2$ (p<0.05), the MNCV at 1.0 w/$cm^2$ was significantly faster than that associated with 0 w/$cm^2$ and 0.5 w/$cm^2$ of ultrasound (p<0.05). CONCLUSIONS: The decreased median motor forearm local temperature and MNCV of the ultrasound treated with 0.0 w/$cm^2$ and 0.5 w/$cm^2$ were attributed to the cooling effect by ultrasound transmission gel. Local forearm temperature and nerve conduction velocity were directly related to the intensity of ultrasound. Alterations in MNCV from ultrasound on healthy nerves appeared to be related to temperature changes induced by thermal effects of ultrasound.

• Bulletin of the Korean Chemical Society
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• v.15 no.5
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• pp.379-386
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• 1994

Reactions of 1',2-bis(diphenylphosphino)-l-(N,N-dimethylaminomethyl)ferrocene (FcNPP) with $M(CO)_6$ (M=Cr, Mo, W) in the presence of TMNO (Trimethylamine oxide) in a stoichiometric ratio of 1 : 1.5 : 3.5 produced a series of Gp 6 metal carbonyl derivatives with a variety of coordination modes: M(CO)$_4({\eta}^2$-FcNPP-P,P) (M=Cr, Mo, W), $M(CO)_5({\eta}^1-FcNPP-P) (M=Mo, W)\;,\; M_2(CO)_9({\eta}^1\;,\;{\eta}^2-FcNPP-P,P,N) (M=Cr, Mo)\;,\;M_2(CO)_{10}({\eta}^1\;,\;{\eta}^1-FcNPP-P,P) (M=Cr, Mo, W)\;, and\;W(CO)_4({\eta}^2-FcNPP(O)-P,N)$. All these complexes were characterized by microanalytical and spectroscopic techniques. In one case, the structure of W(CO)$_4({\eta}^2$-FcNPP(O)-P,N) was determined by X-ray crystallography. Crystals are monocinic, space group P$2_{1/C}$, with a=10.147(2), b=19.902(3), c=19.821(4) ${\AA},\;{\beta}=96.88(2)^{\circ},\;V=3974(l){\AA}^3$, Z=4, and $D_{calc}=1.64 g cm^{-3}$. The geometry around the central tungsten metal is a distorted octahedron, with the nitrogen and phosphorus atoms being cis to each other. Some of these complexes exhibited catalytic activities in the allylic oxidation and epoxidation of cholesterly acetate. Other oxidation products were also formed with the different chemical yields and product distribution depending upon the ligand and the central metal.