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A Study on Customer Purchase Behavior Analysis Based on Hidden Topic Markov Models
Mio Hotoda,Gendo Kumoi,Masayuki Goto 대한산업공학회 2021 Industrial Engineeering & Management Systems Vol.20 No.1
Along with recent developments of Internet society, purchasing actions on E-commerce (hereinafter called “EC”) sites have become common for many consumers. On the other hand, it is known that the conversion rate (hereinafter called “CVR”) on EC sites is usually several percent at most. Therefore, many EC sites desire effective measures to improve CVR. In general, a user browses several pages on an EC site before he/she decide to purchase an item and it is considered that users’ intentions are reflected in their page transition tendency on an EC site. If a model analyzing the page transition data can extract users’ purchasing intentions, it enables to utilize the information for making a good promotion measure. Here, it is sometimes better to assume latent classes behind the users’ page transitions to understand their purchase intentions, because there are usually not only several user groups with different preferences but also plural states of purchasing intentions. However, previous models either assume the same latent topic on each page in the same session or assume a latent topic for each page every time. These models cannot handle situations where users’ intentions may change during browsing but not change frequently from page to page. In this study, we propose a purchasing behavior analysis model based on Hidden Topic Markov Models (HTMM). The proposed method can divide users’ browsing sequence into multiple subsequences with the same statistical characteristics according to latent topics estimated from page transitions. Then, the purchase probability of each latent topic can be obtained by using the purchase results obtained from the actual browsing history data together. By the proposed model, the purchase probabilities become possible to estimate the purchase intention of the users in real time and the information is effective for considering marketing measures. In this study, an experiment using real browsing history data is carried out and the effectiveness of the proposed method is demonstrated.
Characterizing Wooden Texture Using the Affective Engineering Approach
( Mio Ikeda ),( Takashi Toriizuka ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-
There are a lot of furniture and building materials made of wood around us. Some people buy them to stick to tree species and characteristics. However they probably don`t have expert knowledge regarding to woods. Therefore people rely on their senses (sight, smell and touch) when choosing woods. The problems that, example, we feel like a good looking wood, but the feel is bad actually use. Furthermore, picking one of kind of woods, they confuse at large home center. I consider that an index such as the choice of wood sensuously will get to choose the wood easily. The purpose of this research is to identify impression of woods. In addition to characterize woods in term of affective (kansei) engineering. The impression evaluation were examined using fourteen woods with three conditions (sight only, without sight and all sense). The results, the yellow pine, the hinoki and the walnut were woods which everybody feel attracted, but the hard maple, the red oak and the kusu were not feel attracted from relation the level of attraction and the standard deviation. The difference of senses choosing woods made the level of attraction change. Woods which have common impression between sight, sense of touch and smell were become the high level attraction.
Biochemical Properties of Two Lipoxygenases from Pleurotus ostreatus
Mio Kobayashi,Shunya Hayashi,Yuji Tasaki 한국버섯학회 2017 버섯 Vol.21 No.2
The characteristic aroma of mushrooms is one of their attractive elements as food materials. The major aroma compound in most mushrooms is 1-octen-3-ol. The biosynthesis of 1-octen-3-ol starts with the oxidation of linoleic acid by lipoxygenase (LOX). The resultant intermediate hydroperoxide is then cleaved by hydroperoxide lyase. LOX is a non-heme iron-containing dioxygenase widely found in plants, animals, fungi, and bacteria. It catalyzes the insertion of molecular oxygen into polyunsaturated fatty acids containing Z,Z-1,4-pentadiene moieties, such as linoleic acid, linolenic acid, and arachidonic acid, yielding the corresponding hydroperoxides. Two LOX genes, Polox1 and Polox2, have been isolated from P. ostreatus, which has higher LOX activity than other edible mushrooms. Polox1 and Polox2 were found to show different expression patterns during the development of the fruiting body. However, the biochemical properties of PoLOX1 and PoLOX2, encoded by Polox1 and Polox2, respectively, have been not fully elucidated. In this study, we engineered these two LOX genes of P. ostreatus into a heterologous host, Escherichia coli, and characterized the recombinant proteins. The coding regions of Polox1 and Polox2 were amplified by RT-PCR from the total RNA of P. ostreatus PC15 mycelia. The RT-PCR products were digested with appropriate restriction enzymes and ligated into an expression vector (pET-16b). The resultant plasmids were introduced into E. coli BL21 (DE3) via transformation. Polox1 and Polox2 were then expressed by induction at 15°C with 0.4 mM IPTG for 18 h. The cells were harvested by centrifugation and resuspended in 10 mM potassium phosphate buffer (pH 7.0). The cell suspension was sonicated and again centrifuged at 15,000 ×g for 20 min at 4 °C. The resultant cell-free extract was used for subsequent experiments. Recombinant PoLOX1 and PoLOX2 were confirmed by SDS-PAGE analysis of the cell-free extract. PoLOX1 and PoLOX2 were estimated to have molecular weights of approximately 76,000 Da and 78,000 Da, respectively. The LOX activity was determined with linoleic acid as a substrate by a spectrophotometric procedure based on the formation of conjugated dienes. To characterize the biochemical properties of PoLOX1 and PoLOX2, in vitro enzymatic assays were performed using the total cell protein from E. coli expressing the two Polox genes, with linoleic acid as a substrate. The optimum pH of recombinant PoLOX1 and PoLOX2 was 7.5 and 5.5, respectively; the optimum temperatures of recombinant PoLOX1 and PoLOX2 were 55 °C and 30 °C, respectively. Recombinant PoLOX1 and PoLOX2 were stable at pH 5.0-9.0 and 6.0-8.0, respectively; recombinant PoLOX1 and PoLOX2 were relatively stable below 50 °C and 40 °C, respectively. Thus, PoLOX1 had higher thermal and pH stability than PoLOX2. The calculated Km values of PoLOX1 and PoLOX2 were 121 μM and 249 μM, respectively. The calculated Vmax values of PoLOX1 and PoLOX2 were 17.2 μmol/mg・min and 17.5 μmol/mg・min, respectively. These results indicated that PoLOX1 had a higher affinity for linoleic acid than PoLOX2. Collectively, our findings suggested that there were some differences between the biochemical properties of PoLOX1 and PoLOX2.
( Mio Shimomura ),( Shumpei Fujie ),( Kiyoshi Sanada ),( Hiroki Kajimoto ),( Takafumi Hamaoka ),( Motoyuki Iemitsu ) 한국운동영양학회 2021 Physical Activity and Nutrition (Phys Act Nutr) Vol.25 No.1
[Purpose] Aerobic exercise training (AT) reverses aging-induced deterioration of arterial stiffness via increased arterial nitric oxide (NO) production. Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, was decreased by AT. However, whether AT-induced changes in ADMA levels are related to changes in nitrite/nitrate (NOx) levels remains unclear. Accordingly, we aimed to clarify whether the relationship between plasma ADMA and NOx levels affected the AT-induced reduction of arterial stiffness in middle-aged and older adults. [Methods] Thirty-one healthy middle-aged and older male and female subjects (66.4 ± 1.3 years) were randomly divided into two groups: exercise intervention and sedentary controls. Subjects in the training group completed an 8-week AT (60%-70% peak oxygen uptake [V4O2peak] for 45 min, 3 days/week). [Results] AT significantly increased VO<sub>2peak</sub> (P < 0.05) and decreased carotid β-stiffness (P < 0.01). Moreover, plasma ADMA levels were significantly decreased while plasma NOx levels and NOx/ADMA ratio were significantly increased by AT (P < 0.01). Additionally, no sex differences in AT-induced changes of circulating ADMA and NOx levels, NOx/ADMA ratio, and carotid β-stiffness were observed. Furthermore, the AT-induced increase in circulating ADMA levels was negatively correlated with an increase in circulating NOx levels (r = -0.414, P < 0.05), and the AT-induced increase in NOx/ ADMA ratio was negatively correlated with a decrease in carotid β-stiffness (r = -0.514, P < 0.01). [Conclusion] These results suggest that the increase in circulating NOx with reduction of ADMA elicited by AT is associated with a decrease in arterial stiffness regardless of sex in middle-aged and older adults.