• Journal of radiological science and technology
• /
• v.28 no.2
• /
• pp.105-110
• /
• 2005

Background/Aim : Common bile duct (CBD) stones may cause jaundice, cholangitis, or pancreatitis. Extracorporeal shock wave lithotripsy (ESWL) may be needed whenever endoscopic procedure are failed to extract common bile duct stones. The aim of this study is to provide the standard for patient's best choice on ESWL for treatment of CBD stones resistant to endoscopic extraction. Materials and Methods : Fourty-six patients failed in endoscopic stone extraction including mechanical lithotripsy were treated by ESWL. In all patients, endoscopic sphincterotomy and nasobiliary drainage tube was done before ESWL using the ultrasonography for stone localization with a spark-gap type lithotriptor. Patients were sedated with an intravenous injection of 50 mg of Demerol. None were treated under general anesthesia. Results : Overall complete clearance rate of CBD stone was 89.1% (41/46). In 82.6% of the patients, the stones were extracted endoscopically after ESWL, and spontaneous passage was observed in 6.5%. In the clearance rate after ESWL, there were no noticeable differences with regard to number (single: 82.8%, two or three: 100%, more than three: 100%) and size of the stone (less than 33mm: 92.9%, 33 mm or larger: 83.3%), whereas there were significant differences with regard to the ratio of sum of long-axis length of the all stones to sum of long-axis length of the CBD excluding stone (1:2.4, 1:2.1) and diameter of the largest stone to diameter of CBD excluding stone (1:0.9, 1:0.4) for patients with complete clearance compared with those without. Conclusion : We propose that stones without the fragments are travelable sufficient space in CBD or extractable sufficient diameter of CBD regardless of stone size and number should be treated by other technique to prevent time and cost consuming, such as percutaneous transhepatic cholangioscopylithotomy.

• Journal of Service Research and Studies
• /
• v.14 no.2
• /
• pp.82-100
• /
• 2024

Due to the intensifying global technological competition, the strategic and economic importance of intellectual property such as patents as intangible assets is increasing. The purpose of this study is to understand the current status of patent innovation in the service industry and to derive the characteristics and implications of patent innovation in the service industry. To this end, this study conducted an investigation and analysis to understand the characteristics of patent innovation in the service industry based on the data from the business activity survey. The proportion of patent companies in the service industry, characteristics of each service industry, proportion of each service industry, and the number of patent rights holdings were analyzed. In addition, the trend of patent changes in the service industry was investigated. The service industry was compared and analyzed with other industries based on the results of the analysis of patent innovation in the service industry. In particular, the service industry was divided into four types in terms of the rate of increase in the proportion of patent companies and the ratio of patent holing companies, and the types were derived. Based on the analysis results, the characteristics of patent innovation in the service industry were presented. As a result of the study, the proportion of patent holding companies in the service industry was lower than that of other industries, and the gap with other industries was widening, showing that the patent innovation of service companies is lower than that of other industries. The average number of patents held by service industry companies was lower than that of other industries, and the increase rate of the number of patent rights held was also lower than that of other industries, widening the gap. Patent innovation in the service industry can be divided into four quadrants in terms of the rate of increase in the proportion of patent holding companies and the proportion of patent holding companies, and it has been studied that the service industry needs policy support suitable for the characteristics of patent innovation in the quadrant to which the individual service industry belongs.

• Journal of Korean Society of Transportation
• /
• v.26 no.3
• /
• pp.169-178
• /
• 2008

Level of Service (LOS) is one of ways to evaluate operational conditions. It is very important factor in evaluation especially for the facility of highways. However, some studies proved that ${\upsilon}/c$ ratio and accident rate is appeared like a second function which has a U-form. It means there is a gap between LOS and safety of highway facilities. Therefore, this study presents a method for evaluation of a signalized intersection which is considered both smooth traffic operation (delay) and traffic safety (accident). Firstly, as a result of our research, accident rates and EPDO are decreased when it has a big delay. In that reason, it is necessary to make a new Level of Service included traffic safety. Secondly, this study has developed a negative binominal regression model which is based on the relation between accident patterns and stream. Thirdly, standards of LOS are presented which is originated from calculation between annual delay costs and annual accident cost at each intersection. Lastly, worksheet form is presented as an expression to an estimation step of a signalized intersection with traffic accident prediction model and new LOS.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.222-222
• /
• 2012

Metal oxide gas sensors based on semiconductor type have attracted a great deal of attention due to their low cost, flexible production and simple usability. However, most works have been focused on n-type oxides, while the characteristics of p-type oxide gas sensors have been barely studied. An investigation on p-type oxides is very important in that the use of them makes possible the novel sensors such as p-n diode and tandem devices. Monoclinic cupric oxide (CuO) is p-type semiconductor with narrow band gap (~1.2 eV). This is composed of abundant, nontoxic elements on earth, and thus low-cost, environment-friendly devices can be realized. However, gas sensing properties of neat CuO were rarely explored and the mechanism still remains unclear. In this work, the neat CuO layers with highly ordered mesoporous structures were prepared by a template-free, one-pot solution-based method using novel ink solutions, formulated with copper formate tetrahydrate, hexylamine and ethyl cellulose. The shear viscosity of the formulated solutions was 5.79 Pa s at a shear rate of 1 s-1. The solutions were coated on SiO2/Si substrates by spin-coating (ink) and calcined for 1 h at the temperature of $200{\sim}600^{\circ}C$ in air. The surface and cross-sectional morphologies of the formed CuO layers were observed by a focused ion beam scanning electron microscopy (FIB-SEM) and porosity was determined by image analysis using simple computer-programming. XRD analysis showed phase evolutions of the layers, depending on the calcination temperature, and thermal decompositions of the neat precursor and the formulated ink were investigated by TGA and DSC. As a result, the formation of the porous structures was attributed to the vaporization of ethyl cellulose contained in the solutions. Mesoporous CuO, formed with the ink solution, consisted of grains and pores with nano-meter size. All of them were strongly dependent on calcination temperature. Sensing properties toward H2 and C2H5OH gases were examined as a function of operating temperature. High and fast responses toward H2 and C2H5OH gases were discussed in terms of crystallinity, nonstoichiometry and morphological factors such as porosity, grain size and surface-to-volume ratio. To our knowledge, the responses toward H2 and C2H5OH gases of these CuO gas sensors are comparable to previously reported values.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.20 no.3
• /
• pp.107-112
• /
• 2010

The Cu$(In_{1-x}Ga_x)Se_2$ is the absorber material for thin film solar cell with high absorption coefficient of $1{\times}10^5cm^{-1}$. In the case of CIGS, the movable energy band gap from $CuInSe_2$ (1.00 eV) to $CuGaSe_2$ (1.68 eV) can be acquired while controlling Ga contain ratio. Generally, the co-evaporator method have used for development and fabrication of the CIGS absorption layer. However, this method should need many steps and lengthy deposition time with high temperature. For these reasons, in this paper, a new growth method of CIGS layer was attempted to hydride vapor transport (HVT) method. The CIGS mixed-source material reacted for HCl gas in the source zone was deposited on the substrate after transporting to growth zone. c-plane $Al_2O_3$ and undoped GaN were used as substrates for growth. The characteristics of grown samples were measured from SEM and EDS.

• Management & Information Systems Review
• /
• v.34 no.4
• /
• pp.1-13
• /
• 2015

This paper presents a mathematical formulation for container slot chartering model through strategic alliance between liner shipping companies. This paper develops a solution procedure to apply the model to real world problems and its applicability is demonstrated by a numerical example. The model presented in this paper has some important features which have never been considered in the previous researches. The model is linear model and pursuits profit maximization. And also it considers slot chartering capacity selection. This paper attempts to perform sensitivity analysis and compares slot chartering model with basic non-collaborating model in which there is no alliance and collaboration. As a result of sensitivity analysis, some interesting findings are obtained; Even though freight rate is more and more decreasing, the profit by slot chartering model is always higher than the basic model but the profit gaps become smaller. But The ratio of the profit gap to the profit of basic model is more increasing.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.27 no.1
• /
• pp.103-107
• /
• 2000

Traditionally, EPT and thermal tests were used as diagnostic methods for pulp vitality test. The thermal and electrical stimulation tests are the methods to determine the vitality of a tooth based on its neuronal response. These have certain limitations, one of them is the difficulty of approaching the correct result in case of treatment of children. The reason is management problem caused by the unpleasant stimulation. Also, the response from patients are not objective, and false positive or false negative could be happened. Recently, laser doppler flowmetry and pulse oximeter which evaluate vascular integrity are introduced in an effort of overcoming to limitation of traditional methods. The principle of pulse oximeter is to and out level of oxygen saturation by ratio of the two pulses between emitted light and detected light penetrating them to the termination of body, such as ears or fingers. From this point of view, it can be applied to a tooth to determine its vitality. The objective of this study lies mainly on varifying pulse oximeter as a method of determining tooth vitality and providing basic data of its clinical implementation. The result of the research showed that level of oxygen saturation in vital teeth was average of 96.3% and 0.0% in pulpless teeth. As a comprehensive result, pulse oximeter could be an useful diagnostic equipment in determining of tooth vitality.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.11 no.1
• /
• pp.85-95
• /
• 2016

Generally a venture capital aims at investment and support Venture businesses that signifies a start-up which has high technologies but frailty of the economy so that raise fund from financial agencies at high risk rate, it has high risk but when the venture businesses launch into general orbit, the venture capital guarantee high-rate profits. Venture capital do not just provide risk capital but also takes a role as a mentor for continuous growth with total consulting service at business and technical management. Also it offers in-depth support to reform the supported enterprise in order to enhance the competitive. Venture capital receives attention for years as a principal agent to be promoted strategically at national level. Bio venture, a major concern of venture capital and one of core industries in Korea, is different from other industries because it needs long-term and large scale of investment. these factors bring about difficulties in an investment and growth. Therefore, it is very important to identify growth and profitability of start-ups and small and venture businesses with long-term appreciation above all other industries. This research analyze management results of bio venture businesses empirically by investment from venture capital. according to the results, bio venture businesses need huge capital and a long gap of time, henceforth, formation of model for growth is necessary with angel investing as well as venture capital. Since, there are not many listed bio venture businesses, significant statistical result would be limited. This research studied at only economic focus but further study need to examine a question from various angles.

• Korean Journal of Digital Imaging in Medicine
• /
• v.12 no.1
• /
• pp.27-31
• /
• 2010

The purpose of this study was to investigated the usefulness of MR perfusion image comparing with SPECT image. A total of pediatric 30 patients(average age : 7.8) with Moyamoya disease were performed MR Perfusion with 32 channel body coil at 3T from March 01, 2010 to June 10, 2010. The MRI sequences and parameters were as followed : gradient Echo-planar imaging(EPI), TR/TE : 2000ms/50ms, FA : $90^{\circ}$, FOV : $240{\times}240$, Matrix : $128{\times}128$, Thickness : 5mm, Gap : 1.5mm. Images were obtained contrast agent administrated at a rate of 1mL/sec after scan start 10s with a total of slice 1000 images(50 phase/1 slice). It was measured with visual color image and digitize data using MRDx software(IDL version 6.2) and also, it was compared of measurement with values of normal and abnormal ratio to analyze hemodynamic change, and a comparison between perfusion MR with technique using Warm Color at SPECT examination. On MR perfusion examination, the color images from abnormal region to the red collar with rCBV(relative cerebral blood volume) and rCBF(relative cerebral blood flow) caused by increase cerebral blood flow with brain vascular occlusion in surrounding collateral circulation advancement, the blood speed relatively was depicted slowly with blue in MTT(Mean Transit Time) and TTP(Time to Peak) images. The region which was visible abnormally from MR perfusion examination visually were detected as comparison with the same SPECT examination region, would be able to confirm the identical results in MMD(Moyamoya disease)judgments. Hymo-dynamic change in MR perfusion examination produced by increase and delay cerebral blood flow. This change with digitize data and being color imaging makes enable to distinguish between normal and abnormal area. Relatively, MR perfusion examination compared with SPECT examination could bring an excellent image with spatial resolution without radiation expose.

• Journal of Korean Library and Information Science Society
• /
• v.19
• /
• pp.145-209
• /
• 1992

This study, that is made by an on-the-spot survey and a library survey, is aimed at finding some problems in the recognition regarding public library users and suggesting the clue to solve the problems revealed in the way of having compared with 'Book-Room' and Public Library. Poor material was always a troublemaker in this study. Especially the part of 'Book-Room' phenomenon is wholly dependent upon a field survey, that is, interview with a 'book-room' clerks, gathering the advertising leaflets, a close observation on 'Book-Room', etc. There are little printed materials, much less precedent research theses. In the other parts of this paper, there are needed good statistical materials, but the nortion presented in the public library user statistics-for example pupil, students, housewives, old men, the generality of people, etc.- is so vague that it is insufficient and unhelpful for this study. In my judgment, with all these limitations, this article gets some results as follows : 1. 'Book-Room' is the cultural organization which is being operated by, for, of the community inhabitants and it takes on the character of movement - labor movement, cultural movement, and community movement. 2. The pioneer of the Book-Room is 'Yangso Hyupdong chohap' (which means good book- cooperative association) lasted from 1978 to the next year. 3. 'Arom'(means learning) Book-Room is the first real Book-Room at Seomyon district in Pusan established in 1987. 4. Book-Room can be classified by its character as 'Labor BookRoom' and 'Cultural Book-Room'. There are 10 Labor BookRooms and 4 Cultural Book-Rooms in Pusan. 5. Labor Book-Rooms organized themselves to 'Labor Book-Room conference'. 6. Book-Rooms have done their best to extort the needs and interests of the community inhabitants, but relatively public libraries do not, hence the majority of residents are neglected from the public library service. This is at Book-Rooms' back to have been spread so quickly. 7. There is a very large gap between the component ratio of community inhabitants by class and that of public library users by same criterion, that is, in the case of the former, the labor class goes beyond a half point, in the latter, the majority of public library user is composed of students and housewives. 8. Researchers and librarians have concentrated their attention and effort not upon whole residents in community but upon existing users at present time. They do not try to develope potential users. So, researchers' and librarians' recognition regarding the public library users needs to be changed. 9. The concept of 'core-user' may be the key to solve the problems related with public library users. For the purpose of ensuring the 'core-user', it is necessary to study the community and inhabitants.