• Title/Summary/Keyword: Specific volume change

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Voxel-based Morphometry (VBM) Based Assessment of Gray Matter Loss in Medial Temporal Lobe Epilepsy: Comparison with FDG PET (화소기반 형태분석 방법을 이용한 내측측두엽 간질환자의 회백질 부피/농도 감소평가; FDG PET과의 비교)

  • Kang, Hye-Jin;Lee, Ho-Young;Lee, Jae-Sung;Kang, Eun-Joo;Lee, Sang-Gun;Chang, Kee-Hyun;Lee, Dong-Soo
    • The Korean Journal of Nuclear Medicine
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    • v.38 no.1
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    • pp.30-40
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    • 2004
  • Purpose: The aims of this study were to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphometry (VBM) analysis for lateralizing epileptogenic zones in medial temporal lobe epilepsy (mTLE). The findings were compared with fluorodeoxyglucose positron omission tomography (FDG PET). Materials and Methods: MR T1-weighted images of 12 left mTLE and 11 right mTLE patients were compared with those of 37 normal controls. Images were transformed to standard MNI space and averaged in order to create study-specific brain template. Each image was normalized to this local template and brain tissues were segmented. Modulation VBM analysis was performed in order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was peformed using statistical parametric mapping software (SPM99). FDG PET images were compared with those of 22 normal controls using SPM. Results: Gray matter volume was significantly reduced in the left amygdala and hippocampus in left mTLE. In addition, volume of cerebellum, anterior cingulate, and fusiform gyrus in both sides and left insula was reduced. In right mTLE, volume was reduced significantly in right hippocampus. In contrast, FDG uptake was decreased in broad areas of left or right temporal lobes in left TLE and right TLE, respectively. Conclusions: Gray matter loss was found in the ipsilateral hippocampus by modulation VBM analysis in medial temporal lobe epilepsy. This VBM analysis might be useful in lateralizing the epileptogenic zones in medial temporal lobe epilepsy, while SPM analysis of FDG PET disclosed hypometabolic epileptogenic zones.

An analysis of the operational efficiency of the major airports worldwide using DEA and Malmquist productivity indices (세계 주요 공항 운영 효율성 분석: DEA와 Malmquist 생산성 지수 분석을 중심으로)

  • Kim, Hong-Seop;Park, Jeong-Rim
    • Journal of Distribution Science
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    • v.11 no.8
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    • pp.5-14
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    • 2013
  • Purpose - We live in a world of constant change and competition. Many airports have specific competitiveness goals and strategies for achieving and maintaining them. The global economic recession, financial crises, and rising oil prices have resulted in an increasingly important role for facility investment and renewal and the implementation of appropriate policies in ensuring the competitive advantage for airports. It is thus important to analyze the factors that enhance efficiency and productivity for an airport. This study aims to determine the efficiency levels of 20 major airports in East Asia, Europe, and North America. Further, this study also suggests suitable policies and strategies for their development. Research design, data, and methodology - This paper employs the DEA-CCR, DEA-BCC, and DEA-Malmquist production index analysis models to determine airport efficiency. The study uses data on the efficiency and productivity of the world's leading airports between 2006 and 2010. The input variables include the airport size, the number of runways, the size of passenger terminals, and the size of cargo terminals. The output variables include the annual number of passengers and the annual cargo volume. The study uses basic data from the 2010 World Airport Traffic Report (ACI). The world's top 20 airports (as rated by the ACI report) are investigated. The study uses the expanded DEA Model and the Super Efficiency Model to identify the most effective airports among the top 20. The Malmquist productivity index analysis is used to measure airport effectiveness. Results - This study analyzes longitudinal and cross-sectional data on the world's top 20 airports covering 2006 to 2010. A CCR analysis shows that the most efficient airports in 2010 were Gatwick Airport (LGW), Zurich Airport (ZRH), Vienna Airport (VIE), Leonardo da Vinci Fiumicino Airport (FCO), Los Angeles International Airport (LAX), Seattle-Tacoma Airport (SEA), San Francisco Airport (SFO), HongKong Airport (HKG), Beijing Capital International Airport (PEK), and Shanghai Pudong Airport (PVG). We find that changes in airport productivity are affected more by technical factors than by airport efficiency. Conclusions - Based on the study results, we offer four airport development proposals. First, a benchmark airport needs to be identified. Second, inefficiency must be reduced and high-cost factors need to be managed. Third, airport operations should be enhanced through technical innovation. Finally, scientific demand forecasting and facility preparation must become the focus of attention. This paper has some limitations. Because the Malmquist productivity index is based on the hypothesis of the, the identified production change could be over- or under-estimated. Further, as DEA estimates the relative efficiency. It also cannot generalize to include all airport conditions because the variables are limited. To measure airport productivity more accurately, other input variables and environmental variables such as financial and policy factors should be included.

A study on Management Strategy of Italian Hotel Restaurant in Korea (국내호텔 이태리식당 경영전략에 대한 연구)

  • 추상용
    • Culinary science and hospitality research
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    • v.6 no.1
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    • pp.57-78
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    • 2000
  • In the 21st century the size of sales of food service business in Korea will be 30 trillion won which means Food service business in Koreas is a mega market, but it is only quantitative growth and might face the limit of growth. At the same time it is predicted that from the academic world Food service business will develop endlessly after IMF condition. Of course I hope so as a member of national. Al though I propose that quantitative side is important, qualitative side must not be disregarded the present and future customer is needs should be met because the 1st goal of company is to achieve a management goal and pursuit profit. The present situation requires a peculiar and specific strategy of its own which can not be followed by competing hotels so that value can be created and buying intention can be occurred after buying. Until now the goal of marketing campaign has been transacted marketing just for closing a transaction, but it must be related marketing which is seeking mutual interests of customer and company. The strategies to attain these goals are : 1) to change from products and service management-focused to customer management and relationship building-focused. 2) to establish a core strategy which needs to be changed from market occupancy of volume expansion to customer occupancy. 3) to change from one-way communication to two-way communication. 4) to change from large scale marketing by company dimension to small scale marketing by sections. If companies focus on core benefit and augmented service to be sought by customers and make every efforts to create a value customer occupancy will increase automatically, the reduction of marketing cost will be followed, and marketing efforts will be much more efficient. In introducing a new product it is still easier to diffuse through the existing customers, and also important market information can be obtained from customers using this close relationship. If this close relationship maintains well customers will say even a trivial inconvenience and complaint and propose an idea of new product. Kotler divides relationship marketing into 5 stages such as Basic, Reactive, Accountable, Proactive, and Partnership. From the 1st stage to the last stage customer management is absolutely important and also in management strategy. The last stage, Partnership can come into the stage which is actively participated in service development and problem solving by customers. so more loyal customers have more successful performance the company attain.

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NOx Reduction Characteristics of Ship Power Generator Engine SCR Catalysts according to Cell Density Difference (선박 발전기관용 SCR 촉매의 셀 밀도차에 따른 NOx 저감 특성)

  • Kyung-Sun Lim;Myeong-Hwan Im
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.7
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    • pp.1209-1215
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    • 2022
  • The selective catalytic reduction (SCR) is known as a very efficient method to reduce nitrogen oxides (NOx) and the catalyst performs reduction from nitrogen oxides (NOx) to nitrogen (N2) and water vapor (H2O). The catalyst, which is one of the factors determining the performance of the nitrogen oxide (NOx) ruduction method, is known to increase catalyst efficiency as cell density increases. In this study, the reduction characteristics of nitrogen oxides (NOx) under various engine loads investigated. A 100CPSI(60Cell) catalysts was studied through a laboratory-sized simulating device that can simulate the exhaust gas conditions from the power generation engine installed in the training ship SEGERO. The effect of 100CPSI(60Cell) cell density was compared with that of 25.8CPSI(30Cell) cell density that already had NOx reduction data from the SCR manufacturing. The experimental catalysts were honeycomb type and its compositions and materials of V2O5-WO3-TiO2 were retained, with only change on cell density. As a result, the NOx concentration reduction rate from 100CPSI(60Cell) catalyst was 88.5%, and IMO specific NOx emission was 0.99g/kwh satisfying the IMO Tier III NOx emission requirement. The NOx concentration reduction rate from 25.8CPSI(30Cell) was 78%, and IMO specific NOx emission was 2.00g/kwh. Comparing the NOx concentration reduction rate and emission of 100CPSI(60Cell) and 25.8CPSI(30Cell) catalysts, notably, the NOx concentration reduction rate of 100CPSI(60Cell) catalyst was 10.5% higher and its IMO specific NOx emission was about twice less than that of the 25.8CPSI(30Cell) catalysts. Therefore, an efficient NOx reduction effect can be expected by increasing the cell density of catalysts. In other words, effects to production cost reduction, efficient arrangement of engine room and cargo space can be estimated from the reduced catalyst volume.

A Study on the Bake Menu Management with the Menu Engineering (메뉴분석을 통한 베이커리 메뉴관리에 관한 사례연구)

  • Eom Tae Seong;Choe Su Geun
    • Journal of Applied Tourism Food and Beverage Management and Research
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    • v.14 no.2
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    • pp.95-119
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    • 2003
  • Case Study about the management of bakery menu through a menu analysis: This study checked the sales of bakeries this researcher has operated for 4 weeks before evaluating the menu with Kasavana & Smith Analysis, changing the position of the menu on the theoretical base of space composition and then checking the sales for 4 weeks again and analyzing in the same way. The study compared the two groups by using the menu analysis. The menu used in the analysis included 31 items produced in the stores and 29 items turned out from the headquarters. The results of the menu evaluation through Kasavana & Smith Analysis are as follows: (i) before changing the position of the menu 22 Stars, 20 Puzzles, 15 Plowhorses, 13 Dogs (ii) after changing the position 18 Stars, 24 Puzzles, 12 Plowhorses, 6 Dogs During the study, it was inconvenient that many things not thought about before were discovered. The limitations of the study are as below: a) when the displayed items were sold out, they couldn't be supplied continuously. The items from the headquarters were supplied as many as the ordered volume. As the stores prepared materials only for the day, they only produced bakeries as many as the dairy target. So it is difficult for them to keep extra bakery. b) it is natural that a new item make the sales of the existing items cut down. During the study, there appeared a new item, which influenced on the sales. c) as the store this researcher manages is smaller than the others, it was difficult to change all the position of the menu. With only 18 items changing their positions, there couldn't obtain more accurate data. d) because of the franchise contract, there fixed the prices of supply and sale. Therefore the price of Plowhorse couldn't be changed. However on the base of this study, it can search more specific ways to efficiently manage the bakery business in the future.

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Preparation and Characteristics of MWNT/SnO2 Nanocomposites Anode by Colloidal Heterocoagulation for Li-ion Battery (Heterocoagulation 법으로 제조된 이차전지용 MWNT/SnO2 나노복합음극재의 전기화학적 특성)

  • Han, Won-Kyu;Hong, Seok-Jun;Hwang, Gil-Ho;Choa, Yong-Ho;Oh, Sung-Tag;Cho, Jin-Ki;Kang, Sung-Goon
    • Korean Journal of Materials Research
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    • v.18 no.9
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    • pp.457-462
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    • 2008
  • Through the electrostatic interaction between the poly-diallydimethylammonium chloride (PDDA) modified Multi-walled carbon nanotube (MWNT) and $SnO_2$ suspension in 1mM $NaNo_3$ solution, MWNT-$SnO_2$ nanocomposites (MSC) for anode electrodes of a Li-ion battery were successfully fabricated by colloidal heterocoagulation method. TEM observation showed that most of the $SnO_2$ nanoparticles were uniformly deposited on the outside surface of the MWNT. Galvanostatic charge/discharge cycling tests showed that MSC anodes exhibited higher specific capacities than bare MWNT and better cyclability than unsupported nano-$SnO_2$ anodes. Also, after 20 cycles, the MSC anode fabricated by heterocoagulation method showed more stable cycle properties than the simply mixed MSC anode. These improved electrochemical properties are attributed to the MWNT, which adsorbs the mechanical stress induced from volume change and increasing electrical conductivity of the MSC anode, and suppresses the aggregation between the $SnO_2$ nanoparticles.

Manufacture of Iron, Copper and Silver Ions Impregnated Activated Carbon (철, 구리, 은염이 첨착된 활성탄의 제조)

  • Park, Seung-Cho;Choi, Seong-Woo
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.4
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    • pp.384-388
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    • 2006
  • The adsorption ability of polar and toxic substance was greatly enhanced by treating activated carbon with acid solution and impregnating iron, copper, or silver by using in 0.1 M $FeSO_4{\cdot}7H_2O,\;CuSO_4{\cdot}5H_2O,\;AgNO_3$ 300 mL per activated carbon 50 g. Physical and chemical properties of the metal impregnated activated carbons were measured using specific surface area, pore volume and size distribution, scanning eletron microscope(SEM), adsorption isotherm. When activated carbon was treated with acid, the quantity of impregnated metal increased about 1.3 times since the micropores were converted to mesopores or macropores. Both the physical absorption by micropores and chemical absorption by metal ions could be achieved simultaneously with the metal impregnated activated carbon because the capacity of micro pores did not change even after metal ions were impregnated.

Histopathological Studies on the Effect of Korean Safflower (Carthamus tinctorious L.) Seed Powder on Cadmium Poisoning in Mice (홍화씨분말이 카드뮴 중독에 미치는 병리조직학적 관찰)

  • 장종식;권오덕
    • Journal of Veterinary Clinics
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    • v.18 no.2
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    • pp.116-123
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    • 2001
  • This study was undertaken to find out the effect of Korean safflower seed powder on histopathological changes of cadmium toxicity in mice. Fifty BALB/c mice were divided into a control group(A) and four experimental groups(B, C, D, E) : group A received tap water and basal diet, group B received tap water and diet supplemented with 3% Korean safflower seed powder alone, group C received basal diet and 300 $\mu\textrm{g}$/g of cadmium, group D and E received basal diet supplemented with 3% and 10% Korean safflower seed powder and 300$\mu\textrm{g}$/g of cadmium respectively. Cadmium dissolved in tap water was used, and the Korean safflower seed powder were mixed with feed. All mice were dissected on the 56th day. Histopathological changes in liver, kidney, lung, cortical osseous tissue of femoral shaft, bone trabecular of femur, and epiphyseal cartilage plate of femur were observed. Group B showed no significant changes compared with the control group. But group C showed the unclearness of specific cells in liver, the loss of architecture and focal necrosis of hepatocyte, the glomerular swelling, degeneration and necrosis of convoluted tubules, desquamation and vacuolization of the greater part of the renal tubular epithelium, the marked congestion and thickness of the wall of alveolus in lung, slightly thinning of the cortical osseous tissue in femoral shaft, reduction of cancellous bone volume and marked narrowness of bone trabecular, marked thinning of epiphyseal cartilage plate and irregular arrangement of columnar structure of cartilage cells. On the other hand, Korean safflower seed powder-treated group showed a little convalescent changes and maintained their normal architectures in liner, kidney, lung, cortical osseous tissue of femoral shaft, bone trabecular of femur and epiphyseal cartilage plate of femur.

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Studies on the Physicochemical Characteristics of Sesame with Roasting Temperature (볶음과정에서의 참깨의 물리화학적 특성변화)

  • Kim, Hyeon-Wee;Jeong, So-Young;Woo, Sun-Ja
    • Korean Journal of Food Science and Technology
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    • v.31 no.5
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    • pp.1137-1143
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    • 1999
  • The change of physicochemical characteristics of sesame with roasting temperature$(110^{\circ}C{\sim}230^{\circ}C)$ were investigated to get a useful index which needs to manufacture roasted sesame and sesame oils, In the physicochemical properties of roasted sesame, the contents of moisture, specific volume, oil yields and sesame cakes were changed significantly above $170^{\circ}C$. Fat and protein in sesame cakes were changed slightly. Desirable roasting temperature was $220^{\circ}C$ in considering oil yields and sensory qualities. Total amino acids such as arginine, serine, threonine, lysine. cystine, tyrosine and most of the free amino acids, and sucrose of free sugars were reduced significantly above $170^{\circ}C$ and $190^{\circ}C$. respectively. These reductions of sugar and amino compounds were assumed to play an important role in Maillard reaction for the formation of browning pigment, taste and aroma. It was confirmed that this reaction was pyrolytic degradation which took place in water-deficient and oil-rich system at relatively high temperature.

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Preparation of Co3O4/NF Anode for Lithium-ion Batteries

  • Tian, Shiyi;Li, Botao;Zhang, Bochao;Wang, Yang;Yang, Xu;Ye, Han;Xia, Zhijie;Zheng, Guoxu
    • Journal of Electrochemical Science and Technology
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    • v.11 no.4
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    • pp.384-391
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    • 2020
  • Due to its characteristics of light weight, high energy density, good safety, long service life, no memory effect, and environmental friendliness, lithium-ion batteries (LIBs) are widely used in various portable electronic products. The capacity and performance of LIBs largely depend on the performance of electrode materials. Therefore, the development of better positive and negative materials is the focus of current research. The application of metal organic framework materials (MOFs) derivatives in energy storage has attracted much attention and research. Using MOFs as precursors, porous metal oxides and porous carbon materials with controllable structure can be obtained. In this paper, rod-shaped Co-MOF-74 was grown on Ni Foam (NF) by hydrothermal method, and then Co-MOF-74/NF precursor was heat-treated to obtain rodshaped Co3O4/NF. Ni Foam was skeleton structured, which effectively relieved. The change of internal stress changes and destroys the structural volume of the electrode material and reduces the capacity attenuation. Co3O4/NF composite material has a specific discharge capacity of up to 1858 mA h/g for the first time, and a reversible capacity of up to 902.4 mA h/g at a current density of 200 mA/g, and has excellent rate and impedance performance. The synthesis strategy reported in this article opens the way to design high-performance electrodes for energy storage and electrochemical catalysis.