• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.5
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• pp.91-107
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• 2023

Lean startup is a concept that combines the words "lean," meaning an efficient way of running a business, and "startup," meaning a new business. It is often cited as a strategy for minimizing failure in early-stage businesses, especially in software-based startups. By scrutinizing the case of a startup L, this study suggests that lean startup methodology(LSM) can be useful for hardware and manufacturing companies and identifies ways for early startups to successfully implement LSM. To this end, the study explained the core of LSM including the concepts of hypothesis-driven approach, BML feedback loop, minimum viable product(MVP), and pivot. Five criteria to evaluate the successful implementation of LSM were derived from the core concepts and applied to evaluate the case of startup L . The early startup L pivoted its main business model from defecation alert system for patients with limited mobility to one for infants or toddlers, and finally to a smart bottle for infants. In developing the former two products, analyzed from LSM's perspective, company L neither established a specific customer value proposition for its startup idea and nor verified it through MVP experiment, thus failed to create a BML feedback loop. However, through two rounds of pivots, startup L discovered new target customers and customer needs, and was able to establish a successful business model by repeatedly experimenting with MVPs with minimal effort and time. In other words, Company L's case shows that it is essential to go through the customer-market validation stage at the beginning of the business, and that it should be done through an MVP method that does not waste the startup's time and resources. It also shows that it is necessary to abandon and pivot a product or service that customers do not want, even if it is technically superior and functionally complete. Lastly, the study proves that the lean startup methodology is not limited to the software industry, but can also be applied to technology-based hardware industry. The findings of this study can be used as guidelines and methodologies for early-stage companies to minimize failures and to accelerate the process of establishing a business model, scaling up, and going global.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.2
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• pp.65-80
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• 2022

Despite the uncertainty and risky factors of startups, the special and critical role of accelerators in carrying out professional nurturing and investment for them is becoming increasingly significant in the startup social-system. However, academic research on investment determinants that have a profound impact on the survival of accelerators is lacking, and there are only a few empirical studies on the classification and importance of factors, and they do not enjoy the benefits of theoretical studies. This study proposes a business model innovation framework based on the business model innovation theory that reflects the nature and properties of startups that are investment targets of accelerators and derives 12 investment decision factors. The framework defines that the target, direction, and performable force of startup innovation are a business model, strategy, and dynamic capability. Besides, the framework analyzes the investment decision factors of the existing accelerators based on the business model innovation framework to verify the suitability and sufficiency of the composition. As a result of the analysis, first, most of the items were faithfully composed from a static point of view of business model innovation, but it was found that the factors related to the core activities to evaluate the activity and customer relationship were insufficient. Second, from the strategic point of view, the necessity of developing factors that can encompass the definition and content of core resources, which are internal strategic factors, was raised. Third, from the dynamic point of view, it was found that many of the investment determinants of accelerators were concentrated on the lower level of dynamic competencies. This can be judged as a result of reflecting the characteristics of a startup that needs to develop a solution with few resources and a small number of team members. In addition, the roles and interrelationships between each factor are not clear, thus it was found as a limiting point for startups to view and evaluate the direction and process in which startups dynamically innovate their business models. This study is considerably differentiated in that it provides a business model innovation framework and offers a theoretical basis for investment determinants by deriving the investment determinants of accelerators based on the framework and design the foundation for subsequent research. The business model innovation framework presented in this study has great implications in that it contributes to the achievement of startups, accelerators, and startup support organizations.

• Journal of Service Research and Studies
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• v.14 no.1
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• pp.91-107
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• 2024

This study attempted to empirically verify the possibility of K-content for Chinese people who have recently slowed down due to restriction of movement and political and diplomatic conflicts, although it is a very meaningful market for Korea's content industry and tourism industry. As a result of the study, each item of K-content experience, national image, tourism attitude, and visit intention was derived as one factor, and only the national image factor was derived as two factors: 'functional image' and 'cultural image'. As a result of examining the influence relationship between them established based on previous studies focusing on the derived factors, all five research hypotheses were adopted. K-content experience was found to have a significant influence on both factors of the national image. It was found that it had a greater influence on cultural image factors than functional image factors, cultural image factors were found to have a greater influence on tourism attitudes, K-content experiences had a significant effect on tourism attitudes, and tourism attitudes had a significant effect on visit intentions. Based on the results of this study, it was once again confirmed that the national image even comtually bees an important factor for linking to practical tourism behavior, and in this respect, "culture" is an important key factor that can lead to practical tourism and visits. Previous national images indicate that if the functional aspect of the country was more emphasized, it is now necessary to focus more on the importance of culture than on the functional aspect. As the K-content experience has a significant effect on tourism attitude, it can have a positive effect on the formation of a positive tourism attitude that can lead to actual tourism behavior, so various efforts will be needed to form an active tourism attitude using K-content in the future. As the content and target scope of K-content are expanded and diversified, specific strategies for each sub-market using cultural contents in various fields should be established and implemented.

• Korean Journal of Radiology
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• v.24 no.8
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• pp.807-820
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• 2023

Objective: To assess whether computed tomography (CT) conversion across different scan parameters and manufacturers using a routable generative adversarial network (RouteGAN) can improve the accuracy and variability in quantifying interstitial lung disease (ILD) using a deep learning-based automated software. Materials and Methods: This study included patients with ILD who underwent thin-section CT. Unmatched CT images obtained using scanners from four manufacturers (vendors A-D), standard- or low-radiation doses, and sharp or medium kernels were classified into groups 1-7 according to acquisition conditions. CT images in groups 2-7 were converted into the target CT style (Group 1: vendor A, standard dose, and sharp kernel) using a RouteGAN. ILD was quantified on original and converted CT images using a deep learning-based software (Aview, Coreline Soft). The accuracy of quantification was analyzed using the dice similarity coefficient (DSC) and pixel-wise overlap accuracy metrics against manual quantification by a radiologist. Five radiologists evaluated quantification accuracy using a 10-point visual scoring system. Results: Three hundred and fifty CT slices from 150 patients (mean age: 67.6 ± 10.7 years; 56 females) were included. The overlap accuracies for quantifying total abnormalities in groups 2-7 improved after CT conversion (original vs. converted: 0.63 vs. 0.68 for DSC, 0.66 vs. 0.70 for pixel-wise recall, and 0.68 vs. 0.73 for pixel-wise precision; P < 0.002 for all). The DSCs of fibrosis score, honeycombing, and reticulation significantly increased after CT conversion (0.32 vs. 0.64, 0.19 vs. 0.47, and 0.23 vs. 0.54, P < 0.002 for all), whereas those of ground-glass opacity, consolidation, and emphysema did not change significantly or decreased slightly. The radiologists' scores were significantly higher (P < 0.001) and less variable on converted CT. Conclusion: CT conversion using a RouteGAN can improve the accuracy and variability of CT images obtained using different scan parameters and manufacturers in deep learning-based quantification of ILD.

• Korean Journal of Plant Resources
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• v.37 no.1
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• pp.35-61
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• 2024

Floristic study can help to understand the current status of species diversity, evaluate and predict distribution changes of plants based on the specimens, and record the climate environment and biodiversity of the Korean Peninsula. Boraebong is an area that has plant resources of conservation value, but there is concern about artificial interference through trail and forest road. Therefore, this study aims to report the vascular plants of Boraebong based on voucher specimens and photos and to use them as baseline data to conserve biodiversity of Boraebong. Also, it will be useful to prevent additional influx of invasive species through comparison with previous studies. The investigation was carried out 11 times from April to September in 2022 and confirmed a total of 455 taxa including 87 families, 269 genera, 401 species, 13 subspecies, 35 varieties, 6 forms. In addition, we confirmed the 4 taxa of red list plants (EN 2 taxa, NT 2 taxa), 18 taxa of Korean endemic plants, and 102 taxa of floristic target species (V degree 1 taxon, IV degree 16 taxa, III degree 31 taxa, II degree 31 taxa, I degree 23 taxa). Furthermore, alien plants 17 taxa, invasive species 2 taxa, useful plants 439 taxa were confirmed in Boraebong. As the results of comparison with previous studies, 98 total taxa including 38 families, 76 genera, 86 species, 1 subspecies, 8 varieties, 3 forms were newly identified in this study.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.2
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• pp.79-95
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• 2024

The purpose of this study was to find the changes in the habitat of wild birds caused by climate change in urban rivers and protected areas that greatly require ecological functions. In the future, this study can be used as a management index to protect the urban river ecosystem and maintain the health of sustainable urban rivers, thereby ensuring biodiversity. The Tancheon Ecological and Landscape Conservation Area, selected as a target site, has been affected by climate change. The four seasons of Korea have a distinct temperate climate, but the average annual temperature in Seoul has risen by 2.4-2.8℃ over the last 40 years. Winter temperatures tended to gradually increase. Precipitation, which was concentrated from June to August, is now changing into localized torrential rain and a uniform precipitation pattern of several months. Climate change causes irregular and unforeseen features. Climate change has been shown to have various effects on urban river ecosystems. The decrease in the area of water surface and sedimentary land impacted river shape change and has led to large-scale terrestrialization. Plants showed disturbance, and the vegetation was simplified. The emergence of national climate change indicator species, the development of foreign herbaceous plants, the change of dry land native herbaceous species, and wet intelligence vegetation were developed. Wild birds appeared in the territory of winter-summer migratory. In addition, species change and the populations of migratory birds also occurred. It was judged that fluctuations in temperature and precipitation and non-predictive characteristics affect the hydrological environment, plant ecology, and wild birds connecting with the river ecosystem. The results of this study were to analyze how climate change affects the habitat of wild birds and to develop a management index for river ecological and landscape conservation areas where environmental and ecological functions in cities operate. This study can serve as a basic study at the level of ecosystem services to improve the health of urban rivers and create a foundation for biodiversity.

• The Journal of Korean Society for Radiation Therapy
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• v.35
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• pp.23-31
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• 2023

Purpose: The purpose of this study is to evaluate the usefulness of Non-Treat Functionality Volumetric Modulated Arc Therapy(NTF-VMAT) and Treat Functionality VMAT(TF-VMAT) treatment plans in reducing the low-dose area during radiation therapy for patients with multiple metastatic cancers. Materials and Methods: The study was conducted on an Arccheck phantom, treatment planning target locations were set in pairs at intervals of 2 cm, 4 cm, and 6 cm on the X, Y, and Z axes. Based on these location settings, the volume of the low-dose area in NTF-VMAT and TF-VMAT was measured and compared. Results: The results of the study showed that, within a prescription dose range of 10% ~ 70%, the difference in low-dose area volumes across each axis was as follows: On the X-axis, there was a maximum difference of -47.6% and a minimum difference of -2.2%. On the Y-axis, there was a maximum difference of -17.5% and a minimum difference of -7.3%. The Z-axis showed a maximum difference of -39.7%, with the smallest difference being -6.8%. Conclusion: In radiation therapy for patients with multiple metastatic cancers, the TF-VMAT treatment plan was able to reduce the low-dose area by 10-40% compared to NTF-VMAT. This suggests that utilizing Treat Functionality, which includes the Island block technique, improves dose distribution and minimizes side effects, making it beneficial for the treatment of patients with multiple metastatic cancers.

• The Journal of Korean Society for Radiation Therapy
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• v.35
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• pp.41-51
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• 2023

Purpose: This study compares and analyzes the image quality of 3D-CBCT(Cone Beam Computed-Tomography) and Gated CBCT according to baseline changes during SBRT(Stereotactic Body RadioTherapy) in lung cancer patients to find a useful CBCT method for correcting movement due to breathing Materials and methods : Insert a solid tumor material with a diameter of 3 cm into the QUASAR^TM phantom. 4-Dimentional Computed-Tomography(4DCT) images were taken with a speed of the phantom at period 3 sec and a maximum amplitude of 20 mm. Using the contouring menu of the computerized treatment planning system Eclipse^TM Gross Tumor Volume was outlined on solid tumor material. Set-up the same as when acquiring a 4DCT image using Truebeam STx^TM, breathing patterns with baseline changes of 1 mm, 3 mm, and 5 mm were input into the phantom to obtain 3D-CBCT (Spotlight, Full) and Gated-CBCT (Spotlight, Full) images five times repeatedly. The acquired images were compared with the Signal-to-Noise Ratio(SNR), Contrast-to-Noise Ratio(CNR), Tumor Volume Length, and Motion Blurring Ratio(MBR) based on the 4DCT image. Results: The average Signal-to-Noise Ratio, Contrast-to-Noise Ratio, Tumor Volume Length and Motion Blurring Ratio of Spotlight Gated CBCT images were 13.30±0.10%, 7.78±0.16%, 3.55±0.17%, 1.18±0.06%. As a result, Spotlight Gated-CBCT images according to baseline change showed better values than Spotligtht 3D-CBCT images. Also, the average Signal-to-Noise Ratio, Contrast-to-Noise Ratio, Tumor Volume Length and Motion Blurring Ratio of Full Gated CBCT images were 12.80±0.11%, 7.60±0.11%, 3.54±0.16%, 1.18±0.05%. As a result Full GatedCBCT images according to baseline change showed better values than Full 3D-CBCT images. Conclusion : Compared to 3D-CBCT images, Gated-CBCT images had better image quality according to the baseline change, and the effect of Motion Blurring Artifacts caused by breathing was small. Therefore, it is considered useful to image guided using Gated-CBCT when a baseline change occurs due to difficulty in regular breathing during SBRT that exposes high doses in a short period of time

• Journal of Wetlands Research
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• v.26 no.2
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• pp.147-159
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• 2024

Lack of streamflow observations makes model calibration difficult and limits model performance improvement. Satellite-based remote sensing products offer a new alternative as they can be actively utilized to obtain hydrological data. Recently, several studies have shown that artificial intelligence-based solutions are more appropriate than traditional conceptual and physical models. In this study, a data-driven approach combining various recurrent neural networks and decision tree-based algorithms is proposed, and the utilization of satellite remote sensing information for AI training is investigated. The satellite imagery used in this study is from MODIS and SMAP. The proposed approach is validated using publicly available data from 25 watersheds. Inspired by the traditional regionalization approach, a strategy is adopted to learn one data-driven model by integrating data from all basins, and the potential of the proposed approach is evaluated by using a leave-one-out cross-validation regionalization setting to predict streamflow from different basins with one model. The GRU + Light GBM model was found to be a suitable model combination for target basins and showed good streamflow prediction performance in ungauged basins (The average model efficiency coefficient for predicting daily streamflow in 25 ungauged basins is 0.7187) except for the period when streamflow is very small. The influence of satellite remote sensing information was found to be up to 10%, with the additional application of satellite information having a greater impact on streamflow prediction during low or dry seasons than during wet or normal seasons.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.1
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• pp.17-33
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• 2024

This study suggests management planning of Bonguisan Neighborhood Park located on the central of Chuncheon city and highly used for citizen's rest and leisure space utilizing its vegetation structure feature. Bonguisan has been the central of the chuncheon since the period of the Three states in Korean history and consistently damaged, especially in present era, an isolation and sererance of its ecosystem has deepen for indiscreet urban development. The percentage of actual vegetation of Boinguisan Neighborhood Park is as follows: Quercus mongolica is 28.5%, Quercus mongolica - Quercus serrata is 2.1%, Pinus densiflora is 15.6%, Pinus densiflora - Quercus mongolica is 15.9%, Betula schmidtii is 1.6%, Robinia pseudoacacia is 5.9%, Pinus koraiensis is 1.6%. Quercus mongolica is distributed on the southwest, northwest, southeast side of region, Pinus densiflora is distributed on the ridge of east and southeast side of region, Betula schmidtii is distributed on the valley of northeast side region and steep slope region which is on the north side of chungwonsa temple. Pinus densiflora community (Comm. I) and Quercus acutissima - Robinia pseudoacacia community (Comm. V) is expected to undergo succession since it's categorized as Quercus spp. and Quercus mongolica community (Comm. II) and Quercus serrata-Quercus mongolica community (Comm. III), Betula schmidtii community (Comm. IV), Pinus koraiensis community (Comm. VI) is expected to maintain. Also for target vegetation and management planning, Vegetation of Bonguisan Neighborhood Park is classified as 1st Natural landscape conservation and improvement type, 2nd Ecological succession type, 3rd Unusual community conservation type, and 4th Recreation and experience type. And we suggested ecological management measure about each management types. For efficient management of Bonguisan Neighborhood Park, it is need to unify management system of it and after designating Pinus densiflora community and Betula schmidtii community which has high ecological preservation value as an ecological landscape protected area and manage it.