• Title/Summary/Keyword: Media distribution

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Real-time Monitoring of Colloidal Nanoparticles using Light Sheet Dark-field Microscopy Combined with Microfluidic Concentration Gradient Generator (μFCGG-LSDFM)

  • Choe, Hyeokmin;Nho, Hyun Woo;Park, Jonghoon;Kim, Jin Bae;Yoon, Tae Hyun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.365-370
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    • 2014
  • For real-time monitoring of colloidal nanoparticles (NPs) in aqueous media, a light sheet type dark-field microscopy system combined with a microfluidic concentration gradient generator (${\mu}FCGG$-LSDFM) was developed. Various concentrations of colloidal Au NPs were simultaneously generated with the iFCGG and characterized with the LSDFM setup. The number concentrations and hydrodynamic size distributions were measured via particle counting and tracking analysis (PCA and PTA, respectively) approaches. For the 30 nm Au NPs used in this study, the lower detection limit of the LSDFM setup was 3.6 ng/mL, which is about 400 times better than that of optical density measurements under the same ${\mu}FCGG$ system. Additionally, the hydrodynamic diameter distribution of Au NPs was estimated as $39.7{\pm}12.2nm$ with the PTA approach, which agrees well with DLS measurement as well as the manufacturer's specification. We propose this ${\mu}FCGG$-LSDFM setup with features of automatic generation of NP concentration gradient and real-time monitoring of their physicochemical characteristics (e.g., number concentration, and hydrodynamic size distribution) as an important component of future high-throughput screening or high-content analysis platforms of nanotoxicity.

Amorphous Cr-Ti Texture-inducing Layer Underlying (002) Textured bcc-Cr alloy Seed Layer for FePt-C Based Heat-assisted Magnetic Recording Media

  • Jeon, Seong-Jae;Hinata, Shintaro;Saito, Shin
    • Journal of Magnetics
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    • v.21 no.1
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    • pp.35-39
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    • 2016
  • $Cr_{100-x}Ti_x$ amorphous texture-inducing layers (TIL) were investigated to realize highly (002) oriented $L1_0$ FePt-C granular films through hetero-epitaxial growth on the (002) textured bcc-$Cr_{80}Mn_{20}$ seed layer (bcc-SL). As-deposited TILs showed the amorphous phase in Ti content of $30{\leq}x(at%){\leq}75$. Particularly, films with $40{\leq}x{\leq}60$ kept the amorphous phase against the heat treatment over $600^{\circ}C$. It was found that preference of the crystallographic texture for bcc-SLs is directly affected by the structural phase of TILs. (002) crystallographic texture was realized in bcc-SLs deposited on the amorphous TILs ($40{\leq}x{\leq}70$), whereas (110) texture was formed in bcc-SLs overlying on crystalline TILs (x < 30 and x > 70). Correlation between the angular distribution of (002) crystal orientation of bcc-SL evaluated by full width at half maximum of (002) diffraction (FWHM) and a grain diameter of bcc-SL indicated that while the development of the lateral growth for bcc-SL grain reduces FWHM, crystallization of amorphous TILs hinders FWHM. $L1_0$ FePt-C granular films were fabricated under the substrate heating process over $600^{\circ}C$ with having different FWHM of bcc-SL. Hysteresis loops showed that squareness ($M_r/M_s$) of the films increased from 0.87 to 0.95 when FWHM of bcc-SL decreased from $13.7^{\circ}$ to $3.8^{\circ}$. It is suggested that the reduction of (002) FWHM affects to the overlying MgO film as well as FePt-C granular film by means of the hetero-epitaxial growth.

Moderate Effects of Managerial Response on Hotel Ratings of Japanese Tourists (일본인 관광객의 숙박 후기 평점에 대한 관리자 응답의 조절효과)

  • JANG, Juhyeok
    • The Journal of Industrial Distribution & Business
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    • v.10 no.7
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    • pp.83-89
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    • 2019
  • Purpose - It is a very important issue for the Korean tourism industry to increase tourism revenue by attracting foreign tourists. Although Japanese tourists have been an important part of the Korean tourism industry for a long time, the level of tourist satisfaction including accommodation has been at the worst compared to other foreign visitors, which strongly requires concrete solutions. Therefore, this study focuses on improving the satisfaction level of Japanese visitors in the use of accommodation, and find out the influence of the managerial response. Research design, data, and methodology - In this study, customer review and managerial response of hotels in Seoul were collected from "Rakuten Travel" which is the most representative online travel agency in Japan. As a result of collecting data from 2016 to 2018, 6,190 customer reviews and 1,241 managerial responses from 120 hotels were used for analysis. In addition, information on the properties of 120 hotels, such as the number of rooms, classification, types of hotel facilities, types of room facilities, accessibility and prices, were collected. To test the hypotheses, moderated multiple regression analysis was conducted with SPSS 22.0. Results - It was found that only 25 sites, 20.8% of the total 120 sites, were implementing managerial response and average response rate was 66.42% among them. As a result of examining the main effects of the hotel attributes on the ratings, accessibility and price are confirmed as effective variables. We also found that the response rate has a significant moderate effect in both the accessibility and price. In other words, there was a significant difference in the influence of accessibility and price on the ratings depending on the response rate. Also, it was confirmed that the response rate is not a pure moderator variable but a quasi moderator variable. Overall, the evidences partially supported the hypothesis. Conclusion - It was possible to provide important suggestions to the hotel managers who were concerned about managing tourist satisfaction with accessibility problems. It was found that the accessibility problem could be overcome by increasing the response rate. It was also confirmed that high ratings can be more effectively achieved for high priced hotels by increasing the response rate.

A Study on the Direction of Resident Acceptability for Photovoltaic System in Rural region - A Case of the rural village in Munback-myeon, Jincheon-gun, Chungbuk - (농촌지역 태양광발전 주민수용성 방향에 관한 조사 분석 연구 - 충북 진천군 문백면 농촌마을을 중심으로 -)

  • Park, Mi-Lan;Shin, Seung-Wook;Oh, Si-Doek;Kang, Soo-Hyun
    • Journal of the Korean Institute of Rural Architecture
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    • v.21 no.3
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    • pp.77-84
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    • 2019
  • In this study, we classified and analyzed the type and cause of resident conflicts and made a solution at side of resident through resident survey study for research subjects located at photovoltaic system will be installed or not. The factors of resident conflicts based on news media release from 2006 to 2018 were classified to four types such as economic, environmental, technological and procedural factors. According to the news analysis, the types and proportion of resident conflicts in the photovoltaic system projects showed 33% of economic factors, 32% of environmental factor, 21% of technological factor and 14% of procedural factor. This news analysis may suggest that it is very important residents to share the economic benefits as well as to ensure the fairness of the procedures for carrying out the project based on transparent information disclosure during the business promotion and profit distribution stages. We conducted the poll survey in the rural towns where photovoltaic system will be installed or not. The poll survey results showed that (i) there is quite difference in agreement rate and other recognition for sensitive matters such as profit distribution, environmental and technological factors whether photovoltaic system will be installed or not, (ii) the resident conflict regarding the photovoltaic system installation can reduce through direct involvement of residents process. To solve these resident conflicts, the local governments should mainly effort and consider the supporting technologies and consults to solve clearly resident conflicts. In addition, it has to advertise the safety of photovoltaic systems regarding electromagnetic wave which were within the range of scientifically harmless to the human body.

Mass Production and Accumulation Characteristics of Polyhydroxyalkanoates by Fed-batch culture of Alcaligenes eutrophus under Phosphate Limitation (인산염 제한하에서 Alcaligenes eutrophus의 유가식 배양에 의한 Polyhydroxyalkanoates의 대량 산과 축적특성)

  • 류희욱;조경숙;장용근
    • KSBB Journal
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    • v.13 no.2
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    • pp.187-194
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    • 1998
  • For mass production of polyhydroxyalkanoates (PHA), high cell density cultures of Alcaligenes eutrophus by fed-batch culture under phosphate-limitation condition has been investigated. PHA accumulation by the regulation by the regulation of initial phosphate concentration could be automatically induced, and high density cell culture above 200 g/L also could be successfully produced. The production of Poly-$\beta$-hydroxybutyrate (PHB) and dry cell weight increased with increasing the initial phosphate concentration. When the initial concentrations of phosphate were in the ranges of 1.5~4.5 g-PO$_4$/L, PHB and dry cell weight obtained were 83~266 g/L and 61~216 g/L, respectively, and PHB productivity was in the ranges of 1.35~3.10 g/L.h. When a mixture of glucose and propionic acid is used as carbon sources, poly(3-hydroxybutyrate-co-poly-3-hydroxyvalerate), P(3HB-co-3HV), could be also successfully produced under phosphate limitation condition. When the mole ratio of propionic acid to glucose in the feeding solution is 0.22, a final dry cell weight of 150 g/L and a P(3-HB-co-3HV) of 90 g/L were produced. Morphological changes and size distribution of PHB granules synthesized in A. eutrophus under phosphate-limitation condition are determined by TEM during the course of fed-batch. Mean granule diameters of PHB produced are in the range of 0.36~0.39 $\mu$m, and mean cell size was elongated from 0.54~0.59 $\mu$m$\times$ 1.3~1.5 $\mu$m to 0.83~0.89 $\mu$m $\times$2.0~2.3 $\mu$m. Phosphate concentration in media did not affect size distribution of PHB granule and cell.

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A Survey on the Current Status of Management of Fashion Start-up Companies by the Rising Fashion Designers (신진디자이너의 패션스타트업 기업운영 실태조사 연구)

  • Ji, Hye Kyung;Kim, Bock Hee
    • Journal of the Korean Society of Costume
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    • v.67 no.2
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    • pp.131-146
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    • 2017
  • The aim of this study is to investigate the operating characteristics of fashion start-up companies and the characteristics of their founders. For this purpose, this study surveyed fashion start-up companies via online survey in May 2015, and analyzed the data from one hundred companies. The results are as follows. First, for the characteristics of the founders, female founders constituted 65.0% and male founders 35.0%. At the time of establishment, founders aged 26-35 constituted 77.0%. Founders with less than five years of work experience made up about 80%. 82.1% of the founders participated in domestic and foreign exhibitions/fairs. 41.0% of the founders were awarded fashion contest and competition awards, and 33.3% of the founders were supported by rising designer support projects. Second, for the operating characteristics of the start-up companies, clothing at 78.0% was the most popular entrepreneurial item, and the majority targeted the age 20-30 group. 78.0% of the companies had less than 40 production styles per season, and all the enterprises had less than 5 employees. 59.0% of the companies had export experience. Exports to China, Hong Kong, and Japan accounted for 67.4% of all exports. Major distribution channels were mainly select shops(offline select shops 79.8%, online select shops 62.8%). The main methods of promotion were fashion media articles/interviews, product sponsorship, and SNS. The most preferred distribution channel was becoming a part of online/offline select shops(92.6%). Viral marketing(84.4%), star marketing and costume sponsorship(66.7%) were the most preferred method of promotion. The most preferred way to enter foreign markets was to participate in domestic and foreign exhibitions/fairs/trade shows. This study provides basic data necessary for future founders preparing to launch fashion start-up companies. It also aids fashion start-up companies in developing more advanced business operation strategies.

A Study on the Recognition of Organic Food of Housewives in Seoul Area (서울지역 거주 주부들의 유기농산물 인식에 관한 연구)

  • NamKung, Sok;Lee, Jeong-Youn;Kim, Kyu-Dong
    • Food Science and Preservation
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    • v.14 no.6
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    • pp.676-680
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    • 2007
  • This study was conduced to get consumers to use the organic food soundly and to provide useful information to researchers of organic food by investigating the consumers' recognition of organic food. The subjects of this study were the 364 housewives in Seoul area, over the age of 20. The result of this study showed that the respondents' awareness of organic food was average 3.40. And respondents recognized that organic food is healthy(4.05), expensive(3.92), had no chemical fertilizer(3.83), and clean(3.79), in order. The study also showed that only 58.8% of the respondents said that they trust organic food and the major reasons for distrust in organic foods are: it's too expensive(3.90), is no different than non-organic food(3.74), and had unfavorable reports in the media(3.36).

A Study on Disparity Correction of Occlusion using Occluding Patterns (가려짐 패턴을 이용한 가려짐 영역의 시차 교정에 관한 연구)

  • Kim Dae-Hyun;Choi Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.4 s.304
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    • pp.13-20
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    • 2005
  • In this paper, we propose new smoothing filters, i.e., occluding patterns that can accurately correct disparities of occluded areas in the estimated disparity map. An image is composed of several layers and each layer presents similar disparity. Furthermore, the distribution of the estimated disparities has a specific direction around the boundary of the occlusion, and this distribution presents the different direction with respect to the left- and the right-based disparity map. However, typical smoothing filters, such as mean filter and median filter, did not take into account those characteristic. So, they can decrease some error, but they cannot guarantee the accuracy of the corrected disparity. On the contrary, occluding patterns can accurately correct disparities of occluded areas because they consider both the characteristic that occlusion occurs and the characteristic that disparities of the occlusion are ranged, from estimated disparity maps with respect to the left and the right images. We made experiments on occluding patterns with some real stereo image set, and as a result, we can correct disparities of occluded areas more accurately than typical smoothing filters did.

A Clinical study of Paranasal Sinusitis (副鼻洞炎에 關한 臨床的 硏究)

  • Choi, In-hwa;Chae, Byung-yoon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.11 no.1
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    • pp.269-283
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    • 1998
  • Paranasal sinusitis, especially chronic is one of the most common diseases in the field of otolaryngology. It is similar to Bee Yeun(鼻淵) in oriental medicine. Most cases of sinusitis are due to anatomical abnormalities within ostiomeatal unit or disturbed mucocilliary flow. The ostiomeatal unit is the first place of contact with bacteria and allergens during aspiration, and it can be obstructed easily by minute mucosal swelling due to anatomical narrowness. Therefore the treatment of paranasal sinusitis is not easy and often leads to recurrences in spite of long term treatment or surgical therapy. We studied 83 patients who had visited our hospital with complaints of nasal symptoms; they had been diagnosed as having paranasal sinusitis through an endoscopy or CT scan in another hospital and were diagnosed as the paranasal sinusitis through a PNS series. The results were as follows: 1. Age and sex distribution: The most common occurence was found between 6-10 and 1-5 years old. The Males Were 52($62.7\%$) and Females were 31($37.3\%$). 2. By residence 58 cases lived in apts: 25 lived in houses. 3. The longest duration of disease varied from a lower of 13 to a higher of 36 months in 22 cases and from 7 to 12 months in 21 cases. 4. The most common complication & past history with otolaryngologic or allergic disease were adenoid or tonsil hypertrophy & tonsillectomy and adenoidectomy (21 cases). In decreasing order the others were atopic dematitis, otitis media with effusion and allergic rhinitis. 5. Distribution of paranasal sinus disease was most common in both maxillary sinuses in 52 cases. 12 cases showed a normal PNS X-ray series but these had been diagnosed as paranasal sinusitis with an endoscopy or CT scan in another hospital. 6. Common sinusitis - related symptoms were from highest incidence to lowest nasal obstruction, postnasal drip rhinorrhea, frontal headache, cough with sputum. 7. The most administered of prescription was Gamibangpoongtongsungsan and Sunbangpaedoksan extract. 8. In 26 cases the subjects showed significant improvement symptoms in PNS X-ray series : In 21 case showed partial improvement symptoms.

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Electroplating process for the chip component external electrode

  • Lee, Jun-Ho
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2000.11a
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    • pp.1-2
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    • 2000
  • In chip plating, several parameters must be taken into consideration. Current density, solution concentration, pH, solution temperature, components volume, chip and media ratio, barrel geometrical shape were most likely found to have an effect to the process yields. The 3 types of barrels utilized in chip plating industry are the onventional rotating barrel, vibrational barrel(vibarrel), and the centrifugal type. Conventional rotating barrel is a close type and is commonly used. The components inside the barrel are circulated by the barrel's rotation at a horizontal axis. Process yield has known to have higher thickness deviation. The vibrational barrel is an open type which offers a wide exposure to electrolyte resulting to a stable thickness deviation. It rotates in a vertical axis coupled with multi-vibration action to facilitate mixed up and easy transportation of components. The centrifugal barrel has its plated work centrifugally compacted against the cathode ring for superior electrical contact with simultaneous rotary motion. This experiment has determined the effect of barrel vibration intensity to the plating thickness distribution. The procedures carried out in the experiment involved the overall plating process., cleaning, rinse, Nickel plating, Tin-Lead plating. Plating time was adjusted to meet the required specification. All other parameters were maintained constant. Two trials were performed to confirm the consistency of the result. The thickness data of the experiment conducted showed thatbthe average mean value obtained from higher vibrational intensity is nearer to the standard mean. The distribution curve shown has a narrower specification limits and it has a reduced variation around the target value. Generally, intensity control in vi-barrel facilitates mixed up and easy transportation of components. However, it is desirable to maintain an optimum vibration intensity to prevent solution intrusion into the chips' internal electrode. A cathodic reaction can occur in the interface of the external and internal electrode. 2H20 + e $\rightarrow$M/TEX> 20H + H2.. Hydrogen can penetrate into the body and create pressure which can cause cracks. At high intensity, the chip's motion becomes stronger, its contact between each other is delayed and so plating action is being controlled. However, the strong impact created by its collision can damage the external electrode's structure there by resulting to bad plating condition.

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