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        검색결과 46

        21.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        모바일 게임 시장이 스마트폰 중심으로 변화되기 시작하면서 모바일 게임에서는 오토 플레이 시스템이 적용되기 시작하였다. 오토플레이 시스템은 버튼 한번으로 게임을 자동으로 진행하는 시스템 이며 현재 거의 대부분의 모바일 게임에서 적용되었고 PC게임에서 까지 이러한 시스템이 적용되고 있다. 하지만 이러한 오토 플레이 시스템의 성능은 매우 비효율적으로 행동하고 있으며 본 논문에서는 플레이어의 행동 패턴을 기반으로 학습한 인공지능을 제안하고자 한다. 본 논문에서 제안하는 인공지능 모델은 플레이어가 게임을 진행하면서 게임 데이터와 플레이어가 입력한 버튼 값을 학습 데이터로 저장하고 학습데이터를 DNN(Deep Neural Network) 신경망 모델을 사용하여 학습하였다. 게임에서는 플레이어가 중복적으로 다른 버튼을 동시에 누르기 때문에 Output Layer를 다층으로 분류하여 학습을 진행했다. 본 논문 실험에서는 20명의 실험자들에게 제안하는 인공지능 모델을 사용함으로써 결과를 기록하였고 트랙을 일정하게 벽을 부딪치지 않고 달린 플레이어 데이터만 제대로 학습되어 결과를 얻을 수 있었고 그렇지 않은 플레이어의 데이터는 캐릭터가 제대로 이동하지 않아 결과 값을 얻을 수가 없었다. 또한 간단한 아케이드 게임을 만들어 강화학습과 비교하였으며 강화학습보다 성능은 좋지 않았지만 학습속도가 약 10배 빨랐다.
        4,500원
        22.
        2018.11 구독 인증기관·개인회원 무료
        Microenvironments surrounded with various extracellular matrix (ECM) components can decide specifically the fate of spermatogonial stem cells (SSCs) and integrin heterodimers recognizing directly ECM proteins play an important role in transporting ECM-derived signals into cytoplasm, resulting in inducing a variety of biological functions such as cell attachment, self-renewal and differentiation. However, to date, studies on type of integrin heterodimers expressed functionally on the undifferentiated SSCs derived from mouse with hybrid strain remain unclear. Therefore, we tried to investigate systematically what kind of integrin heterodimers are expressed transcriptionally, translationally and functionally in the SSCs derived from testis of hybrid (B6CBAF1) mouse. For these, magnetic activated cell sorting (MACS) using Thy1 antibody was used for isolating SSCs from testis, and real-time PCR or fluorescence immunoassay was conducted for measuring transcriptional or translational level of integrin α and β subunits in the isolated SSCs. Subsequently, antibody inhibition assay was conducted for confirming functionality of presumed integrin heterodimers. As the results, transcriptional levels of genes encoding total 25 integrin subunits were quantified, 7 integrin α (α4, α6, α7, α9, αV, αL and αE) and 2 integrin β (β1 and β5) subunit genes showed significantly increased transcriptional up-regulation, compared to the other integrin subunit genes. In contrast, integrin α3, α5, α10 and α11, and integrin β2, β3, β4 and β7 were weakly transcribed. When translational levels of the integrin α subunits showing high transcription level (α4, α6, α7, α9, αV, αL and αE) were measured, significantly strong translational up-regulation of integrin α6, α7, α9, αV and αL subunit genes were detected, whereas integrin α4 and αE subunit genes were weakly. In case of integrin β subunit, β1 evaluated more expression than β5. Based on these results, we speculated that the undifferentiated SSCs derived from B6CBAF1 mouse might express integrin α4β 1, α6β1, α7β1, α9β1, αVβ1 or αVβ5 on plasma membrane. Subsequently, the hybrid strain SSCs showed significantly increased adhesion to fibronectin, laminin, tenascine-C and vitronectin and functional blocking of integrin α4β1, α6β1, α9β1, and αVβ1 or αVβ5 in SSCs significantly inhibited attachment to fibronectin, laminin, tenascin-C and vitronectin, respectively. Accordingly, we could identify that the hybrid (B6CBAF1) mouse-derived SSCs had integrin α4β1, α6β1, α9β1, αVβ1 or αVβ5 on plasma membrane. Moreover, this information will greatly contribute to constructing non-cellular niche supporting self-renewal of SSCs in the future.
        23.
        2018.09 구독 인증기관·개인회원 무료
        Glutathione S-transferase (GST) is a key gene involved in multiple stress tolerance in all living organisms, though it is still to be disclosed the gene function in teff grass [Eragrostis tef (Zucc.)Trotter].The objectives of this study were to clone and molecular characterization of GST gene in teff grass. We characterized GST1 from teff grass (EtGST1), it composed of a 645-bp open reading frame (ORF) that encoded 195 amino acid residue. Further, we transformed EtGST1 in E.coli BL21 (DE3) cells. This recombinant EtGST1 in E.coli BL21(DE3) induced at 37°C temperature. In addition, Growth of cells overexpressing EtGST1 rapidly increased in the presence of polyethylene glycol (5%), heat (46°C), NaCl (0.6%), and arsenic (1 mM) than that of cells harboring an empty vector. These results suggest that EtGST1 would be suitable candidate for improving tolerance in forages and/or grasses species against multiple abiotic stresses.
        24.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 기존에 재배된 바 없었던 암대극을 새로운 관상식물로 개발하고자, 절화 특성 평가를 실시하였다. 2017년 3월과 4월, 제주도에 자생하고 있는 암대극을 채취한 후, 수분흡수, 절화수명, 노화 과정 등 절화수명 특성을 평가하였다. 또한 sucrose 농도, 절화길이, pH 농도, 저장온도에 따른 절화 특성을 조사하였다. 본 실험은 국립수목원 유용식물증식센터의 Phyto-garden system(12h photoperiod, 25℃, 70% RH)과 실온(23℃, 44% RH)에서 수행하였고 2~3일 간격으로 수분흡수량, 생체중, 절화수명을 측정하였다. 실험 환경에 따른 연구에서 실온(14.4일) 보다 phyto-garden system(42.4일)의 절화 수명이 약 3배 더 길었고, 절화길이에 따른 연구에서는 절화수명이 20cm, 15.2일, 40cm, 17.4일로 나타났다. Sucrose 농도에 따른 연구에서는 처리에 따른 절화수명 증진 효과는 없었고, pH에 따른 연구의 절화수명은 pH 5, 15.6일, pH 6, 13.4일, pH 7, 13.1일, 증류수, 14.8일이었다. 저장온도에 따른 실험에서, 절화수명은 4℃, 83일, 10℃, 41.2일, 15℃, 35.5 일, 20℃, 17.4일, 실온, 14.4일이었는데, 온도가 감소할수록 절화수명이 길어짐을 알 수 있었다. 결론적으로, 암대극은 비교적 광도와 습도가 높은 환경과 절화길이가 길고 저장온도가 낮을수록 수명이 오래 유지되는 것을 알 수 있었다.
        4,000원
        25.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Near infrared spectroscopy (NIRS) is a rapid and accurate method for analyzing the quality of cereals, and dried animal forage. However, one limitation of this method is its inability to measure fermentation parameters in dried and ground samples because they are volatile, and therefore, respectively lost during the drying process. In order to overcome this limitation, in this study, fresh coarse haylage was used to test the potential of NIRS to accurately determine chemical composition and fermentation parameters. Fresh coarse Italian ryegrass haylage samples were scanned at 1 nm intervals over a wavelength range of 680 to 2500 nm, and optical data were recorded as log 1/reflectance. Spectral data, together with first- and second-order derivatives, were analyzed using partial least squares (PLS) multivariate regressions; scatter correction procedures (standard normal variate and detrend) were used in order to reduce the effect of extraneous noise. Optimum calibrations were selected based on their low standard error of cross validation (SECV) values. Further, ratio of performance deviation, obtained by dividing the standard deviation of reference values by SECV values, was used to evaluate the reliability of predictive models. Our results showed that the NIRS method can predict chemical constituents accurately (correlation coefficient of cross validation, R2 cv, ranged from 0.76 to 0.97); the exception to this result was crude ash (R2 cv = 0.49 and RPD = 2.09). Comparison of mathematical treatments for raw spectra showed that second-order derivatives yielded better predictions than first-order derivatives. The best mathematical treatment for DM, ADF, and NDF, respectively was 2, 16, 16, whereas the best mathematical treatment for CP and crude ash, respectively was 2, 8, 8. The calibration models for fermentation parameters had low predictive accuracy for acetic, propionic, and butyric acids (RPD < 2.5). However, pH, and lactic and total acids were predicted with considerable accuracy (R2 cv 0.73 to 0.78; RPD values exceeded 2.5), and the best mathematical treatment for them was 1, 8, 8. Our findings show that, when fresh haylage is used, NIRS-based calibrations are reliable for the prediction of haylage characteristics, and therefore useful for the assessment of the forage quality.
        4,000원
        26.
        2017.05 구독 인증기관·개인회원 무료
        Generally, fate of spematogonial stem cells (SSCs) can be determined specifically by microenvironments enclosed with various extracellular matrix (ECM) components and integrins recognizing directly ECM proteins play an pivotal role in transporting ECM-derived signals into cytoplasm, resulting in inducing a variety of biological functions such as cell attachment, self-renewal and differentiation. However, to date, studies on type of integrins expressed on the undifferentiated SSCs remain unclear. Therefore, we tried to investigate systematically what kind of integrin subunits are expressed transcriptionally or translationally in the SSCs derived from testis of hybrid B6CBAF1 mouse. For these, isolation of SSCs from testis were conducted by magnetic activated cell sorting (MACS) using Thy1 antibody. Subsequently, transcriptional and translational level of integrin α and β subunits in the isolated SSCs were measured by real-time PCR and fluorescene immunoassay, respectively. As the results, transcriptional levels of genes encoding total 25 integrin subunits were quantified, and integrin α4, α6, α7, α9, αV, αL and αE and integrin β1, β5 showed higher expression levels than other subunits. By contrast, integrin α3, α5, α 10 and α11 and integrin β2, β3, β4, β7 were weakly transcribed. When translational levels of the integrin α subunits showing high transcription level (α4, α6, α7, α9, αV αL, and αE) were measured, integrin α6, α7, α9, αV and αL were higher than integrin α4 and αE. In case of integrin β subunit, β1 evaluated more expression than β5. From these results, we speculate that the undifferentiated SSCs derived from hybrid B6CBAF1 mouse may express integrin α4β1, α6β1, α7β1, α9β1, αVβ1 and/or αVβ5 on plasma membrane. Moreover, this information will greatly contribute to constructing non-cellular niche supporting self-renewal of SSCs in the future.
        28.
        2016.10 구독 인증기관·개인회원 무료
        A self-powered time-temperature indicator (TTI) was optimized to enhance the performance of the TTI by modifying a biofuel cell using different immobilization, redox mediators, and status of electrode. The performance of the TTI was measured by output voltage of the TTI. The enzymes and combinations of lacasse mediators (HBT (1-hydroxybenzotriazole), Rupy (Bis-(bipyridine)-(5-aminophenanthroline) ruthenium bis (hexafluorophosphate)), MB (Methylene blue), SDP (4,4- sulfonyldiphenol)) and glucose oxidase mediators (FA (Ferroceneboxaldehyde), DBQ(2,5-dihydroxybenzoquinone), HQS (8-hydroxyquinoline-5sulfonic acid hydrate), FHFP (Ferrocenium hexafluorophosphate)) were immobilized with stabilizers (pyrrole) on a glassy carbon electrode by electrodeposition by applying a square wave, cross-linking and physical immobilization. MWCNTs were used to modify glassy carbon electrodes. MWCNTs coated electrodes produced higher output voltage than uncoated electrodes. The optimum and stable performance of the self-powered TTI was that the output voltage of 64 mV and duration time was 3hr at 25°C, when the combination of Rupy, MB for laccase mediators and HQS, FHFP for glucose oxidase mediators were immobilized on MWCNTs coated electrodes by applying a square wave method. In the application, the concentrations of enzyme and glucose were adjusted to prolong the shelf-life of TTI at much lower output voltage.
        29.
        2016.10 구독 인증기관·개인회원 무료
        The pasteurization is employed for extending shelf-life and keeping the quality of products constant. However the pasteurization undesirably accelerates the oxidation of beer which renders volatile compounds concerning off-flavor. The pasteurization conditions was optimized to avoid off-flavor of beer during pasteurization. Under the isothermal condition, thermal destruction kinetics such as D and Z value of Lactobacillus brevis which is reported the most common beer spoilage, was determined. The binomial data (detected or non-detected of off-flavor) was treated with logistic regression to estimate off-flavor development (OFD) times. The temperature dependence of OFD times was established in terms of Arrhenius relationships. Optimized pasteurization temperature and time were found at which OFD times was not detected. The constraint for optimization was that the pasteurization degree should be larger than 5 decimal reduction time. The optimization was conducted through mathematical simulation using kinetics and temperature-dependent models for microbial death and OFD times. The optimized results were validated by the corresponding experimentations, which met the requirements that the concentration of Lactobacillus brevis was 5-Log reduction and the OFD times not detected.
        30.
        2016.10 구독 인증기관·개인회원 무료
        Makgeolli is rich in nutrients such as beneficial microbial species, essential amino acids, oligosaccharides, and organic acids. The lactic acid bacteria contained in Makgeolli provides a healthy function as probiotics for customers. The purpose of this study was to enhance the nutritional properties, lactic acid bacteria propagation and alcohol contents of makgeolli by controlling redox potential balance. An automatic control system was created using ORP sensor, Labview control kit, and air supplier, in which air concentration was controlled by on & off mode. Makgeolli was fermented at three different redox potentials -50 mV, -100 mV, -150 mV. Regulating of aeration according to the redox potentials could give prominence to nutritional benefits of Makgeolli. The profiles of redox potential appeared bathtub curves, and related to lactic acid bacteria growth curve and byproducts. We could find the optimum redox potential balance that affects the factors such as LAB’s, alcohol contents and byproducts. In conclusion it was essential to control redox potential balance in order to produce nutrients rich Makgeolli.
        31.
        2016.10 구독 인증기관·개인회원 무료
        A novel nanocomposite LDPE film with UV protective properties was developed for active packaging applications. Initially, undoped and Mn-doped TiO2 nanoparticles (NPs) were synthesized by the sol-gel method and the resulting particles were characterized. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed an agglomerated nature and spherical morphology. X-ray diffraction (XRD) studies indicated that all products were crystalline and in the form of rutile. The reflectance spectrum of undoped TiO2 NPs demonstrated a characteristic sharp edge at 410 nm. Subsequently, nanocomposite (NC) LDPE samples were prepared with the NPs by solvent precipitation followed by film casting. The optical and thermal properties of the NC samples were investigated. Incremental increases in Mn concentration from 0.25 mol % to 1.00 mol % were associated with progressive decreases in light transmission in the UV region. The melting and maximum decomposition temperatures of all NCs were 107 and 442-449 °C, respectively. The UV protective LDPE-based NC films exhibited superior photostability. Absorption in the FTIR spectra at 1716 and 1734 cm-1 changed after 4-wk exposure to UV for all film samples as a consequence of photodegradation. Finally, the photooxidation of perilla oil was assessed as an example of a UV protective packaging application. After 12 days, protection with 1.00 mol% Mn-doped TiO2-LDPE was associated with a gradual increase in PV, while protection with TiO2-LDPE was associated with a significant increase and protection with the control treatment was associated with a dramatic increase in PV. Hence, a 1.00 mol% Mn-doped TiO2-LDPE NC showed promise for UV shielding packaging applications.
        32.
        2016.10 구독 인증기관·개인회원 무료
        Time-temperature indicators or integrators (TTIs) indicate food quality changes based on time-temperature history. Whilst many types of TTIs have been developed and commercialized, educated consumers often refuse to purchase food products with attached TTI labels showing even a slight color change. In this study, a novel on-off diffusion-based TTI coupled with polydiacetylene/silica nanocomposites has been proposed. The prototype TTI tag has a multilayer structure comprised of a self-adhesive base layer, a middle microporous sheet, and an upper opaque white layer coupled with a square reservoir of Tween 20 attached to an activation stripe. At the end of the diffusion path, polydiacetylene/silica nanocomposites were injected into a loading site as a fine blue stripe. After activation, Tween 20 diffused and reached the loading site, where it rapidly changed from blue-to-red via solvatochromism. This alternative and innovative TTI continuously showed a blue color until reaching the end point, at which stage a red color rapidly appeared, indicating product rejection. Thus, this novel TTI it is of great benefit to the brand owner. The developed prototype was characterized and evaluated for its ability to monitor microbial quality based on published, isothermal, microbial growth data of modified-atmosphere packaged minced beef, Mediterranean fish, and ground pork. The diffusion of Tween 20 in the TTI system was measured under various isothermal conditions and a kinetic model, based on the association between diffusion and time-temperature, was investigated. The Gaussian-estimated activation energy value was 51.082kJ mol-1. Tween 20 diffusion of 6.10, 5.15 and 6.15mm along the TTI systems were considered to be end points and the 95% confidence interval between the times taken for TTI to display OFF and for the foods to reach their deterioration thresholds were 23.30-23.70, 23.00-23.50 and 23.44-24.05h for total aerobic bacteria, Shewanella putrefaciens, and Pseudomonas spp. respectively. The TTI performance test for reproducibility and accuracy revealed a normal frequency distribution with 35004.90, 1200.254.82 and 549.811.09min at 0, 11 and 25C, respectively in accordance with the investigation of diffusion in the TTI.
        33.
        2016.04 구독 인증기관·개인회원 무료
        Microbe have been considered as potential control agents for pest, as alternative to chemical control methods. Among entomopathogens, fungi cause the mortality by penetrating the cuticle of pest and/or by metabolites such as toxin. Not only this direct control effect of fungi, but repellency of fungi also may be used to prevent the pest. Repellence effect of fungi is considered as inhibitory factor to control termite. A study was reported in Japan that termite was able to detect and remove the conidia of fungi on their surface. The termite can escape from fungal infection and protect their colony. There is few study that insect pest such as moth can detect and avoid the virulence fungi. Therefore, we has been conducting the detection and avoidance of beet armyworm to high pathogenic fungi, Paecilomyces fumosoroseus. Adult of the beet armyworm avoided oviposition at Chinese cabbage treated with P. fumosoroseus compare to control. This result may be used to prevent the infestation of moth in crop production.
        34.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study attempts to manufacture a Ni-Cr-Al-Y coating layer using a kinetic spray process and investigates the microstructure and physical properties of the manufactured layer. The Ni-22Cr-10Al-1Y (wt.%) composition powder is used, and it has a spherical shape with an average diameter of 23.7 μm. Cu plate is used as the substrate. Optical microscope, X-ray diffraction, scanning electron microscope and Vickers hardness test are carried out to characterize the macroscopic properties of the coating layer. Furthermore, the coating layer underwent vacuum heat treatment at temperatures of 400˚C and 600˚C for 1 hour to check the effect of heat treatment temperature on the properties. The manufactured coating layer is 1.5 mm thick, and featured identical phases to those found in the powder. The porosity of the coating layer is measured at 2.99%, and the hardness is obtained at 490.57 Hv. The layer shows reduced porosity as heat treatment temperature increased, and hardness is reduced at 400˚C but shows a slight increase at 600˚C. Based on the findings described above, this study also discusses possible manufacturing methods for a Ni-Cr-Al-Y coating layer using the kinetic spray process.
        4,000원
        35.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the adsorption of Na on graphene and graphene oxide, which are used as anode materials in sodium ion batteries, using density functional theory. The adsorption energy for Na on graphene was -0.507 eV at the hollow sites, implying that adsorption was favorable. In the case of graphene oxide, Na atoms were separately adsorbed on the epoxide and hydroxyl functional groups. The adsorption of Na on graphene oxide-epoxide (adsorption energy of -1.024 eV) was found to be stronger than the adsorption of Na on pristine graphene. However, the adsorption of Na on graphene oxide-hydroxyl resulted in the generation of NaOH as a by-product. Using density of states (DOS) calculations, we found that the DOS of the Na-adsorbed graphene was shifted down more than that of the Na-adsorbed graphene oxide-epoxide. In addition, the intensity of the DOS around the Fermi level for the Na-adsorbed graphene was higher than that for the Na-adsorbed graphene oxide-epoxide.
        4,000원
        36.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Spermatogonial stem cells (SSCs) developed into sperms through spermatogenesis have been utilized as a useful tool in the field of regenerative medicine and infertility. However, a small number of highly qualified SSCs are resided in the seminiferous tubule of testis, resulted in developing effective in-vitro culture system of SSCs for solving simultaneously quantitative and qualitative problems. Presently, SSCs can be enriched on testicular stromal cells (TSCs), but there are no systematic researches about TSC culture. Therefore, we tried to optimize culture condition of TSCs derived from mouse with different strains. For these, proliferation and viability were measured and compared by culturing ICR outbred or DBA/2 inbred mouse-derived TSCs at 35 or 37℃. In case of ICR strain, primary TSCs cultured at 37℃ showed significantly higher proliferation and viability than those at 35℃ and significant increase of proliferation and viability in sub-passaged TSCs was detected in the 35℃ culture condition. Moreover, sub-passage of primary TSCs at 35℃ induced no significant effects on proliferation and viability. In contrast, in case of DBA/2 strain, significantly improved proliferation were detected in the primary TSCs cultured at 35℃, which showed no significant difference in the viability, compared to those at 37℃. Furthermore, sub-passaged TSCs cultured at 37℃ showed no significant differences in proliferation and viability, compared to those at 35℃. However, with significant decrease of proliferation induced by sub-passage of primary TSCs at 35℃, no significant effects on proliferation and viability were resulted from sub-passage of primary TSCs at 37℃. From these results, culture temperature of primary TSCs derived from outbred and inbred strain of mouse could be separately optimized in primary culture and subculture.
        4,000원
        37.
        2013.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,300원
        39.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Several lines of evidence suggest that osteocytes play a critical role in bone remodeling. Both healthy and apoptotic osteocytes can send signals to other bone surface cells such as osteoblasts, osteoclasts, osteoclast precursors, and bone lining cells through canalicular networks. Osteocytes responding to mechanical strain may also send signals to other cells. To determine the role for osteocytes an mechanical strain in bone remodeling, we examined the effects of fluid flow shear stress on osteoclast precursor cell and osteoblast proliferation and recruitment induced by osteocytes. In addition, the effects of fluid flow shear stress on osteocyte M-CSF, RANKL, and OPG mRNA expression were also examined. MLO-Y4 cells were used as an in vitro model for osteocytes, RAW 264.7 cells and MOCP-5 cells as osteoclast precursors, and 2T3 cells as osteoblasts. MLO-Y4 cells conditioned medium (Y4-CM) was collected after 24h culture. For fluid flow experiments, MLO-Y4 cells were exposed to 2h of pulsatile fluid flow (PFF) at 2, 4, 8, 16±0.6dynes/cm² using the Flexcell StreamerTM system. For proliferation assays, MOCP-5, RAW 264.7, and 2T3 cells were cultured with control media or 10-100% Y4 CM. Cells were cultured for 3d, and then cells were counted. RAW 264.7 and 2T3 cell migration was assayed using transwells with control media or 10-100% Y4-CM. M-CSF, RANKL and OPG in MLO-Y4 mRNA expression was determined by semiquantitative RT-PCR. Y4-CM increased osteoclast precursor proliferation and migration, but decreased 2T3 cell proliferation and migration. CM from MLO-Y4 cells exposed to PFF caused decreased RAW 267.4 cell proliferation and migration and 2T3 migration compared to control Y4-CM. However, Y4-CM from cells exposed to PFF had no effect on 2T3 osteoblastic cell proliferation. PFF decreased RNAKL mRNA and increased OPG mRNA in MLO-Y4 cells compared to control(without PFF). PFF had no effect on M-CSF mRNA expression in MLO-Y4 cells. These results suggest that osteocytes can regulate bone remodeling by communication with osteoclast precursors and osteoblasts and that osteocytes can communicate mechanical signals to other cells.
        4,000원
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