Analysis of the tourist movement patterns of Jeju Island, Republic of Korea

El Big Data es una de las herramientas más utilizadas en la actualidad para la gestión de las actividades turísticas. Su incorporación en el análisis de los patrones de desplazamiento de visitantes se hace esencial tanto para caracterizar el interés de los visitantes con respecto a ciertos lugares, o para la planificación de la movilidad regional. Este estudio identifica y analiza varias características de la actividad turística en la isla de Jeju (Corea del Sur). Como unidades de análisis se utilizan los puntos de interés (POIs, definidos como lugares con especial concentración de visitantes). Para ello se han analizado los patrones de movimiento, tanto de turistas como de residentes. La fuente de datos para identificar los POIs han sido los puntos calientes deducidos de la concentración de fotografías georreferenciadas de la plataforma Flickr, realizadas en la isla de Jeju entre los años 2010 y 2019 por los usuarios de esa plataforma. A partir del análisis de estos datos se ha incrementado el conocimiento de la actividad turística del área identificando las preferencias y tendencias de las visitas y los patrones espaciales y temporales que revelan los lugares más visitados dentro del área de estudio. Este mejor conocimiento se puede usar para una planificación y gestión más inteligente de la actividad de los destinos turísticos, permitiendo tanto a las autoridades como a las industrias turísticas, ofrecer servicios mejores, más adecuados a la demanda y compatibles con los criterios de sostenibilidad que se determinen. En el caso de estudio, se pone de manifiesto la tendencia de viajes de tipo ‘staycations’ (en los que el visitante viaja cerca de su domicilio habitual). Los POIs más representativos de Jeju son: el Pico Seongsanilchulbong, el Cabo Seopjikoji, Museo de Teddy Bear y las Cascadas Cheonjiyeon. Las zonas más visitadas son: el centro de las ciudades de Jeju y Seogwipo, el Centro Turístico Jungmun y el Pico Seongsanilchulbong y sus alrededores. Así mismo, este estudio ha permitido proponer nuevas rutas para el autobús turístico que presta servicio en las ciudades de Jeju y Seogwipo, respectivamente, para optimizar la movilidad turística sin dañar la calidad del medio ambiente.Big Data is one of the most widely utilized tools for the efficient tourism management. The use of Big Data in the analysis of the movement patterns becomes essential for both characterizing the visitor preferences with respect to Points of interest (POIs, defined as specific point locations that people may find attractive and interesting) and facilitating interregional mobility. This study identifies various characteristics of tourism activity and spatio-temporal patterns on Jeju Island (South Korea). For this purpose, the movement patterns of both tourists and residents have been analyzed. The data has been collected from the georeferenced photos on Flickr, taken on Jeju Island between 2010 and 2019 by users of this photo-sharing platform. The paper explores the tourism trend of ‘staycations’, which means a tendency of the frequent trip to local attractions near their home (Oxford, 2021). The most representative POIs in Jeju Island are: Seongsan Ilchulbong Peak, Seopjikoji, Teddy Bear Museum and Cheonjiyeon Falls. The most popular areas are: the center of Jeju City and Seogwipo City, Jeju Jungmun Resort, Seongsan Ilchulbong Peak and its surrounding area. Moreover, this study proposes new routes for the city tour bus in Jeju City and Seogwipo City, respectively to strengthen the environmental sustainability and effective implementation by optimizing tourist mobility through the network analysis. The methodology and strategic vision of this study feature significantly in the approach to their management plans of sustainable tourism for other local government, tourism industry and organization as well.Depto. de GeografíaFac. de Geografía e HistoriaTRUEunpu

End-to-End Learnable Multi-Scale Feature Compression for VCM

The proliferation of deep learning-based machine vision applications has given rise to a new type of compression, so called video coding for machine (VCM). VCM differs from traditional video coding in that it is optimized for machine vision performance instead of human visual quality. In the feature compression track of MPEG-VCM, multi-scale features extracted from images are subject to compression. Recent feature compression works have demonstrated that the versatile video coding (VVC) standard-based approach can achieve a BD-rate reduction of up to 96% against MPEG-VCM feature anchor. However, it is still sub-optimal as VVC was not designed for extracted features but for natural images. Moreover, the high encoding complexity of VVC makes it difficult to design a lightweight encoder without sacrificing performance. To address these challenges, we propose a novel multi-scale feature compression method that enables both the end-to-end optimization on the extracted features and the design of lightweight encoders. The proposed model combines a learnable compressor with a multi-scale feature fusion network so that the redundancy in the multi-scale features is effectively removed. Instead of simply cascading the fusion network and the compression network, we integrate the fusion and encoding processes in an interleaved way. Our model first encodes a larger-scale feature to obtain a latent representation and then fuses the latent with a smaller-scale feature. This process is successively performed until the smallest-scale feature is fused and then the encoded latent at the final stage is entropy-coded for transmission. The results show that our model outperforms previous approaches by at least 52% BD-rate reduction and has $\times5$ to $\times27$ times less encoding time for object detection. It is noteworthy that our model can attain near-lossless task performance with only 0.002-0.003% of the uncompressed feature data size.Comment: Under peer review for IEEE TCSV

Hepatocellular Carcinoma Arising in a Huge Hepatocellular Adenoma with Bone Marrow Metaplasia

Hepatocellular adenoma (HCA) is the most common type of benign liver tumor, and its major complication is malignant transformation to hepatocellular carcinoma (HCC). Here, we report a case of HCC arising in HCA with bone marrow metaplasia in a 24-year-old Korean woman who presented with abdominal discomfort. A huge liver mass was found on abdominal ultrasonography. She underwent surgical hepatic resection, and the resected specimen was entirely involved by a 20-cm-sized tumor. Histological review revealed a well differentiated HCC arising from inflammatory HCA with β-catenin nuclear positivity and bone marrow metaplasia that contained hematopoietic cells. This case was unique because malignant transformation, inflammatory type HCA, β-catenin nuclear staining, and bone marrow metaplasia were simultaneously observed. Additionally, it should be noted that a large HCA with β-catenin activation can undergo malignant transformation and should be surgically resected in a timely manner

Modelling Surround-aware Contrast Sensitivity for HDR Displays

Despite advances in display technology, many existing applications rely on psychophysical datasets of human perception gathered using older, sometimes outdated displays. As a result, there exists the underlying assumption that such measurements can be carried over to the new viewing conditions of more modern technology. We have conducted a series of psychophysical experiments to explore contrast sensitivity using a state-of-the-art HDR display, taking into account not only the spatial frequency and luminance of the stimuli but also their surrounding luminance levels. From our data, we have derived a novel surroundaware contrast sensitivity function (CSF), which predicts human contrast sensitivity more accurately. We additionally provide a practical version that retains the benefits of our full model, while enabling easy backward compatibility and consistently producing good results across many existing applications that make use of CSF models. We show examples of effective HDR video compression using a transfer function derived from our CSF, tone-mapping, and improved accuracy in visual difference prediction

Concomitant renal insufficiency and diabetes mellitus as prognostic factors for acute myocardial infarction

<p>Abstract</p> <p>Background</p> <p>Diabetes mellitus and renal dysfunction are prognostic factors after acute myocardial infarction (AMI). However, few studies have assessed the effects of renal insufficiency in association with diabetes in the context of AMI. Here, we investigated the clinical outcomes according to the concomitance of renal dysfunction and diabetes mellitus in patients with AMI.</p> <p>Methods</p> <p>From November 2005 to August 2008, 9905 patients (63 ± 13 years; 70% men) with AMI were enrolled in a nationwide prospective Korea Acute Myocardial Infarction Registry (KAMIR) and were categorized into 4 groups: Group I (n = 5700) had neither diabetes nor renal insufficiency (glomerular filtration rate [GFR] ≥ 60 ml/min/1.73 m²), Group II (n = 1730) had diabetes but no renal insufficiency, Group III (n = 1431) had no diabetes but renal insufficiency, and Group IV (n = 1044) had both diabetes and renal insufficiency. The primary endpoints were major adverse cardiac events (MACE), including a composite of all cause-of-death, myocardial infarction, target lesion revascularization, and coronary artery bypass graft after 1-year clinical follow-up.</p> <p>Results</p> <p>Primary endpoints occurred in 1804 (18.2%) patients. There were significant differences in composite MACE among the 4 groups (Group I, 12.5%; Group II, 15.7%; Group III, 30.5%; Group IV, 36.5%; <it>p </it>< 0.001). In a Cox proportional hazards model, after adjusting for multiple covariates, the 1-year mortality increased stepwise from Group III to IV as compared with Group I (hazard ratio [HR], 1.96; 95% confidence interval [CI], 1.34-2.86; <it>p </it>= 0.001; and HR, 2.42; 95% CI, 1.62-3.62; <it>p </it>< 0.001, respectively). However, Kaplan-Meier analysis showed no significant difference in probability of death at 1 year between Group III and IV (p = 0.288).</p> <p>Conclusions</p> <p>Renal insufficiency, especially in association with diabetes, is associated with the occurrence of composite MACE and indicates poor prognosis in patients with AMI. Categorization of patients with diabetes and/or renal insufficiency provides valuable information for early-risk stratification of AMI patients.</p

Optic Neuropathy Associated with Castleman Disease

A 44-year-old woman with Castleman disease presented with acute visual loss in the left eye. A full ophthalmologic examination and imaging were performed. Visual acuity was 20/20 in the right eye and 20/100 in the left eye. Total dyschromatopsia, a relative afferent pupillary defect, and a cecocentral scotoma were observed in the left eye. Mild disc edema, without leaking during fluorescein angiography, was also observed. Magnetic resonance imaging revealed a small cystic epidermoid-like lesion in the right prepontine and suprasellar cistern. Her visual acuity did not improve and deteriorated to 20/200 in the left eye at 22 months after the initial visual loss. Optic neuropathy may rarely be associated with Castleman disease and suggests a poor prognosis

Retinoid production using metabolically engineered Escherichia coli with a two-phase culture system

<p>Abstract</p> <p>Background</p> <p>Retinoids are lipophilic isoprenoids composed of a cyclic group and a linear chain with a hydrophilic end group. These compounds include retinol, retinal, retinoic acid, retinyl esters, and various derivatives of these structures. Retinoids are used as cosmetic agents and effective pharmaceuticals for skin diseases. Retinal, an immediate precursor of retinoids, is derived by β-carotene 15,15'-mono(di)oxygenase (BCM(D)O) from β-carotene, which is synthesized from the isoprenoid building blocks isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). Retinoids are chemically unstable and biologically degraded via retinoic acid. Although extensive studies have been performed on the microbial production of carotenoids, retinoid production using microbial metabolic engineering has not been reported. Here, we report retinoid production using engineered <it>Escherichia coli </it>that express exogenous BCM(D)O and the mevalonate (MVA) pathway for the building blocks synthesis in combination with a two-phase culture system using a dodecane overlay.</p> <p>Results</p> <p>Among the BCM(D)O tested in <it>E. coli</it>, the synthetic retinoid synthesis protein (SR), based on bacteriorhodopsin-related protein-like homolog (Blh) of the uncultured marine bacteria 66A03, showed the highest β-carotene cleavage activity with no residual intracellular β-carotene. By introducing the exogenous MVA pathway, 8.7 mg/L of retinal was produced, which is 4-fold higher production than that of augmenting the MEP pathway (<it>dxs </it>overexpression). There was a large gap between retinal production and β-carotene consumption using the exogenous MVA pathway; therefore, the retinal derivatives were analyzed. The derivatives, except for retinoic acid, that formed were identified, and the levels of retinal, retinol, and retinyl acetate were measured. Amounts as high as 95 mg/L retinoids were obtained from engineered <it>E. coli </it>DH5α harboring the synthetic <it>SR </it>gene and the exogenous MVA pathway in addition to <it>dxs </it>overexpression, which were cultured at 29°C for 72 hours with 2YT medium containing 2.0% (w/v) glycerol as the main carbon source. However, a significant level of intracellular degradation of the retinoids was also observed in the culture. To prevent degradation of the intracellular retinoids through <it>in situ </it>extraction from the cells, a two-phase culture system with dodecane was used. The highest level of retinoid production (136 mg/L) was obtained after 72 hours with 5 mL of dodecane overlaid on a 5 mL culture.</p> <p>Conclusions</p> <p>In this study, we successfully produced 136 mg/L retinoids, which were composed of 67 mg/L retinal, 54 mg/L retinol, and 15 mg/L retinyl acetate, using a two-phase culture system with dodecane, which produced 68-fold more retinoids than the initial level of production (2.2 mg/L). Our results demonstrate the potential use of <it>E. coli </it>as a promising microbial cell factory for retinoid production.</p

Utilizing PCL microcarriers for high-purity isolation of primary endothelial cells for tissue engineering

Endothelial cells (ECs) are widely used in research, both for fundamental vascular biology research and for exploring strategies to create engineered vascularized tissues. Primary isolation often results in contamination from fibroblasts and vascular smooth muscle cells that can potentially affect function, particularly during the initial expansion period needed to establish the cell culture. In the current study, we explored the use of microcarriers to selectively isolate ECs from the lumen of intact vessels to enhance the purity during the isolation procedure. First, rat aortic explant culture was performed and after 2 weeks of culture, flow cytometry revealed that only 60% of the expanded cell population was positive for the endothelial marker CD31. Then, we employed a strategy to selectively isolate ECs and improve their purity by introducing microcarriers to the lumen of intact aorta. After 10 days, microcarriers were carefully removed and placed in cell culture dishes and at 15 days, a large near confluent layer of primary ECs populated the dish. Flow cytometry revealed that >90% of the expanded cells expressed CD31. Moreover, the cells were capable of forming tubule-like structures when plated onto Matrigel, confirming their function also. The highly modular and transportable nature of microcarriers has significant potential for isolating ECs at high purity, with minimal contamination

Incomplete Distal Renal Tubular Acidosis with Nephrocalcinosis

We report the case of a female patient with incomplete distal renal tubular acidosis with nephrocalcinosis. She was admitted to the hospital because of acute pyelonephritis. Imaging studies showed dual medullary nephrocalcinosis. Subsequent evaluations revealed hypokalemia, hypocalcemia, hypercalciuria, and hypocitraturia with normal acid-base status. A modified tubular acidification test with NH4Cl confirmed a defect of urine acidification, which is compatible with incomplete distal tubular acidosis. We treated our patient with potassium citrate, which corrects hypokalemia and prevents further deposition of calcium salts