• 대한수학회논문집
• /
• 제33권1호
• /
• pp.345-360
• /
• 2018

In finance, barrier options are options contracts with a payoff that depends on whether the price of the underlying asset hits a predetermined barrier level during the option's lifetime. Based on exotic options and random fluctuations of interest rates in the marketplace, we consider discount barrier options with a stochastic interest rate driven by the Hull-White process. This paper derives the closed-form solutions of the discount barrier option and the discount double barrier option using Mellin transform methods and the PDE (partial differential equation) method of images.

• International Journal of Costume and Fashion
• /
• 제18권2호
• /
• pp.29-43
• /
• 2018

Service-learning is a form of experiential education in which students participate in organized activities and develop a sense of civic responsibility while acquiring content knowledge of the discipline. The purpose of this study was first, to examine the underlying theories and principles of service-learning, and second, to present a case of systemic implementation of problem-based service-learning into a Product Innovation and Management class in higher education. The New Product Development for an E-Commerce Small Business project was developed for a community partner, BevShots, reflecting the needs of the firm, and was tightly woven into the course content. Students' participation in the project had a significant effect on increasing their awareness of the needs in the community and identifying their roles as citizens as well as enhancing their content knowledge learning. The community partner also received benefits for his business by participating in the project. Through this study, we aim to inspire fashion design and merchandising educators to implement service-learning projects/classes in the curriculum.

• Applied Microscopy
• /
• 제48권4호
• /
• pp.96-101
• /
• 2018

The release of nanoscale membrane-bound vesicles is common in all three domains of life. These vesicles are involved in a variety of biological processes such as cell-to-cell communication, horizontal gene transfer, and substrate transport. Prokaryotes including bacteria and archaea release membrane vesicles (MVs) (20 to 400 nm in diameter) into their extracellular milieu. In spite of structural differences in cell envelope, both Gram-positive and negative bacteria produce MVs that contain the cell membrane of each bacterial species. Archaeal MVs characteristically show surface-layer encircling the vesicles. Filamentous fungi and yeasts as eukaryotic microbes produce bilayered exosomes that have varying electron density. Microbes also form intracellular vesicles and minicells that are similar to MVs and exosomes in shape. Electron and fluorescence microscopy could reveal the presence of DNA in MVs and exosomes. Given the biogenesis of extracellular vesicles from the donor cell, in situ high-resolution microscopy can provide insights on the structural mechanisms underlying the formation and release of microbial extracellular vesicles.

• Journal of Genetic Medicine
• /
• 제17권2호
• /
• pp.108-111
• /
• 2020

Short stature homeobox-containing gene (SHOX) is a well-known causative gene for the short stature in Turner syndrome. The clinical manifestation of SHOX gene related disorders varies from SHOX haploinsufficiency, presenting with idiopathic short stature, disproportionate short stature, or Leri-Weill dyschondrosteosis (LWD) to recessive form of extreme dwarfism and limb deformity in Langer mesomelic dysplasia. LWD is usually diagnosed upon suspicion based on short stature and skeletal abnormalities, and it is rarely accompanied with respiratory failure in the neonatal period. Here, we report the case of a newborn infant with LWD presenting with severe micrognathia that caused respiratory distress, which was diagnosed using microarray testing. Even when the manifestation of Madelung deformity is not yet apparent, LWD should be considered as one of underlying diseases related to congenital micrognathia.

• Nutrition Research and Practice
• /
• 제15권4호
• /
• pp.411-430
• /
• 2021

Irritable bowel syndrome (IBS) is a frequently diagnosed gastrointestinal (GI) disorder characterized by recurrent abdominal pain, bloating, and changes in the stool form or frequency without any structural changes and overt inflammation. It is not a life-threatening condition but causes a considerable level of discomfort and distress. Among the many pathophysiologic factors, such as altered GI motility, visceral hypersensitivity, and low-grade mucosal inflammation, as well as other immunologic, psychologic, and genetic factors, gut microbiota imbalance (dysbiosis), which is frequently found in IBS, has been highlighted as an etiology of IBS. Dysbiosis may affect gut mucosal homeostasis, immune function, metabolic regulation, and even visceral motor function. As diet is shown to play a fundamental role in the gut microbiota profile, this review discusses the influence of diet on IBS occurring through the modulation of gut microbiota. Based on previous studies, it appears that dietary modulation of the gut microbiota may be effective for the alleviation of IBS symptoms and, also an effective IBS management strategy based on the underlying mechanism; especially because, IBS currently has no specific treatment owing to its uncertain etiology.

• Communications for Statistical Applications and Methods
• /
• 제28권3호
• /
• pp.281-294
• /
• 2021

In this paper, we propose an adaptive regression method based on the single-layer neural network structure. We adopt a symmetric activation function as units of the structure. The activation function has a flexibility of its form with a parametrization and has a localizing property that is useful to improve the quality of estimation. In order to provide a spatially adaptive estimator, we regularize coefficients of the activation functions via ℓ₁-penalization, through which the activation functions to be regarded as unnecessary are removed. In implementation, an efficient coordinate descent algorithm is applied for the proposed estimator. To obtain the stable results of estimation, we present an initialization scheme suited for our structure. Model selection procedure based on the Akaike information criterion is described. The simulation results show that the proposed estimator performs favorably in relation to existing methods and recovers the local structure of the underlying function based on the sample.

• 구강생물연구
• /
• 제42권4호
• /
• pp.248-253
• /
• 2018

Cemental tears are uncommon form of root fracture that can lead to rapid localized periodontal attachment loss. Studies have described periodontal breakdown as being associated with the separation of the cementum from the underlying tooth structure. The aim of this case report is to assess the outcome of treatment of cemental tear with several surgical treatment regimens. Three patients with cemental tear were treated with different surgical method. In all three cases, the cemental tear occurred on maxillary right central incisors. In each case, the root fragment were removed, the localized defect was treated using different surgical methods including guided tissue regeneration and bone graft followed by scaling and root planting. In all three cases, symptoms subsided after the treatment and clinical attachment level was improved up to 2 mm at 3 month after surgery. Both conventional and regenerative periodontal surgery could achieve successful outcomes.

• The Korean Journal of Legal Medicine
• /
• 제42권4호
• /
• pp.164-167
• /
• 2018

Aspergillus infection is the most common cause of death due to fungi in immunocompromised hosts. Aspergillus tracheobronchitis is an uncommon but severe form of invasive pulmonary aspergillosis, which is limited entirely or mainly to the tracheobronchial tree and can often be life-threatening. We report a case of a 54-year-old man who died from Aspergillus tracheobronchitis without an underlying disease. Autopsy revealed an extensive yellowish plaque adhering to the trachea and bronchial wall. The microscopic examination of the trachea and bronchus revealed septate branching hyphae of Aspergillus.

• Journal of Korean Neurosurgical Society
• /
• 제64권3호
• /
• pp.367-373
• /
• 2021

Secondary neurulation (SN) is a critical process to form the neural tube in the posterior region of the body including the tail. SN is distinct from the anteriorly occurring primary neurulation (PN); whereas the PN proceeds by folding an epithelial neural plate, SN precursors arise from a specified epiblast by epithelial-to-mesenchymal transition (EMT), and undergo self-renewal in the tail bud. They finally differentiate into the neural tube through mesenchymal-to-epithelial transition (MET). We here overview recent progresses in the studies of SN with a particular focus on the regulation of cell lineage, self-renewal, and EMT/MET. Cellular mechanisms underlying SN help to understand the functional diversity of the tail in vertebrates.

• BMB Reports
• /
• 제56권4호
• /
• pp.225-233
• /
• 2023

Hepatocellular carcinoma (HCC) is a very common form of cancer worldwide and is often fatal. Although the histopathology of HCC is characterized by metabolic pathophysiology, fibrosis, and cirrhosis, the focus of treatment has been on eliminating HCC. Recently, three-dimensional (3D) multicellular hepatic spheroid (MCHS) models have provided a) new therapeutic strategies for progressive fibrotic liver diseases, such as antifibrotic and anti-inflammatory drugs, b) molecular targets, and c) treatments for metabolic dysregulation. MCHS models provide a potent anti-cancer tool because they can mimic a) tumor complexity and heterogeneity, b) the 3D context of tumor cells, and c) the gradients of physiological parameters that are characteristic of tumors in vivo. However, the information provided by an multicelluar tumor spheroid (MCTS) model must always be considered in the context of tumors in vivo. This mini-review summarizes what is known about tumor HCC heterogeneity and complexity and the advances provided by MCHS models for innovations in drug development to combat liver diseases.