Peridynamic modeling for crack propagation analysis of materials

In this paper, the computer simulations are carried out by using the peridynamic theory model with various conditions including quasi-static loads, dynamic loads and crack propagation, branching crack pattern and isotropic materials, orthotropic materials. Three examples, a plate with a hole under quasi-static loading, a plate with a pre-existing crack under dynamic loading and a lamina with a pre-existing crack under quasi-static loading are analyzed by computational simulations. In order to simulate the quasi-static load, an adaptive dynamic relaxation technique is used. In the orthotropic material analysis, a homogenization method is used considering the strain energy density ratio between the classical continuum mechanics and the peridynamic. As a result, crack propagation and branching cracks are observed successfully and the direction and initiation of the crack are also captured within the peridynamic modeling. In case of applying peridynamic used homogenization method to a relatively complicated orthotropic material, it is also verified by comparing with experimental result

Sequence-to-Sequence Prediction of Vehicle Trajectory via LSTM Encoder-Decoder Architecture

In this paper, we propose a deep learning based vehicle trajectory prediction technique which can generate the future trajectory sequence of surrounding vehicles in real time. We employ the encoder-decoder architecture which analyzes the pattern underlying in the past trajectory using the long short-term memory (LSTM) based encoder and generates the future trajectory sequence using the LSTM based decoder. This structure produces the $K$ most likely trajectory candidates over occupancy grid map by employing the beam search technique which keeps the $K$ locally best candidates from the decoder output. The experiments conducted on highway traffic scenarios show that the prediction accuracy of the proposed method is significantly higher than the conventional trajectory prediction techniques

Progression from Chronic Atrophic Gastritis to Gastric Cancer; Tangle, Toggle, Tackle with Korea Red Ginseng

Key molecular players that link inflammation to carcinogenesis are prostaglandins, cytokines, nuclear factor-κB (NF-κB), chemokines, angiogenic growth factors, and free radicals, all of which lead to increased mutations and altered functions of important enzymes and proteins, for example, activation of oncogenic products and/or inhibition of tumor suppressor proteins, in inflamed tissues, thus contributing to multi-stage carcinogenesis process. Interpreted reversely, the identification of the molecular mechanisms by which chronic inflammation increases cancer risk or optimal intervention of targeted drugs or agents during the inflammation-associated carcinogenic process could be a necessary basis for developing new strategy of cancer prevention at many sites. In this review, we discuss the possibilities for cancer prevention by controlling inflammation process in Helicobacter pylori (H. pylori)-associated inflamed stomach with Korea red ginseng. Korea red ginseng is a good example of a natural herb that has ubiquitous properties that are conductive to stop inflammatory carcinogenesis that is un wanted outcome of H. pylori infection, rendering rejuvenation of chronic atrophic gastritis

Growth characteristics and productivity of cold-tolerant “Kowinearly” Italian ryegrass in the northern part of South Korea

The objective of this research is to evaluate differences in growth characteristics and productivity between Kowinearly and Florida 80 Italian ryegrass varieties in regions with severely cold winters. This research was carried out in Suwon (in central South Korea) and Yonchun (in northern South Korea) during the 2002 2006 growing seasons. Kowinearly is a diploid variety with green leaf colour and a semi prostrate growth habit in autumn and a semi-erect one in spring. There were differences among the varieties in terms of cold tolerance, heading date, and forage yield in Yonchun. The winter field survival of Kowinearly was 85%, while that of Florida 80 was 43%. The dry matter yield of Kowinearly in Yonchun was 9,662 kg/ha, which was 31% more than that of Florida 80. In Suwon, the heading date of Kowinearly was May 7, which was 2 days later than that of Florida 80. In Yonchun, Kowinearly’s heading date was May 12, 1 day earlier than that of Florida 80. These results indicate that Kowinearly has good cold tolerance, and that in spring, it starts growth earlier than Florida 80, because of its higher cold tolerance.Keywords: Italian ryegrass, Kowinearly, cold tolerance, new variety, forage cro

Assessment of RELAP/MOD3 using BETHSY 6.2TC 6-inch cold leg side break comparative test

This report presents the results of the RELAP5/MOD3 Version 7j assessment on BETHSY 6.2TC. BETHSY 6.2TC test corresponding to a six inch cold leg break LOCA of the Pressurizer Water Reactor(PWR). The primary objective of the test was to provide reference data of two facilities of different scales (BETHSY and LSTF facility). On the other hand, the present calculation aims at analysis of RELAP5/N4OD3 capability on the small break LOCA simulation, The results of calculation have shown that the RELAP5/MOD3 reasonably predicts occurrences as well as trends of the major phenomena such as primary pressure, timing of loop seal clearing, liquid hold up, etc. However, some disagreements also have been found in the predictions of loop seal clearing, collapsed core water level after loop seal clearing, and accumulator injection behaviors. For better understanding of discrepancies in same predictions, several sensitivity calculations have been performed as well. These include the changes of two-phase discharge coefficient at the break junction and some corrections of the interphase drag term. As result, change of a single parameter has not improved the overall predictions and it has been found that the interphase drag model has still large uncertainties

Pig-to-Nonhuman Primate (NHP) Naked Islet Xenotransplantation

Islet transplantation is an established therapy for selected type 1 diabetes (T1D) patients with severe hypoglycemic unawareness and glycemic liability despite of insulin treatment. However, the donor organ is limited. Porcine islets are the best alternative source to overcome this limitation, and pig-to-nonhuman primate (NHP) naked islet xenotransplantation studies are being performed worldwide. Several studies including our own have presented successful proof-of-concept results based on immunosuppression regimen including the anti-CD154 monoclonal antibody. Particularly, long-term control of diabetes by adult porcine islet transplantation has been demonstrated in five consecutive monkeys, and the longest survival was ~1000 days after transplantation. Currently, pig-to-NHP islet xenotransplantation based on clinically applicable immunosuppression regimen is being pursued. In this chapter, we will describe all the procedures of pig-to-NHP naked islet xenotransplantation: (1) the porcine islet isolation from designated pathogen-free (DPF) miniature pigs, (2) diabetes induction in monkeys, (3) transplantation procedure via the portal vein, (4) immune monitoring comprising humoral and cellular immunity after porcine islet transplantation, and finally (5) liver biopsy and subsequent immunohistochemical procedure in detail