• Journal of Korean Neurosurgical Society
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• v.46 no.5
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• pp.479-483
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• 2009

Objective : A mouse model of spinal cord injury (SCI) could further increase our basic understanding of the mechanisms involved in injury and repair of the nervous system. The purpose of this study was to investigate whether methods used to produce and evaluate photochemical graded ischemic SCI in rats, could be successfully adapted to mice, in a reliable and reproducible manner. Methods : Thirty female imprinting control region mice (weighting 25-30 g, 8 weeks of age) were used in this study. Following intraperitoneal injection of Rose bengal, the translucent dorsal surface of the T8-T9 vertebral laminae of the mice were illuminated with a fiber optic bundle of a cold light source. The mice were divided into three groups; Group 1 (20 mg/kg Rose bengal, 5 minutes illumination), Group 2 (20 mg/kg Rose bengal, 10 minutes illumination), and Group 3 (40 mg/kg Rose bengal, 10 minutes illumination). The locomotor function, according to the Basso-Beattie-Bresnahan scale, was assessed at three days after the injury and then once per week for four weeks. The animals were sacrificed at 28 days after the injury, and the histopathology of the lesions was assessed. Results : The mice in group 1 had no hindlimb movement until seven days after the injury. Most mice had later recovery with movement in more than two joints at 28 days after injury. There was limited recovery of one joint, with only slight movement, for the mice in groups 2 and 3. The histopathology showed that the mice in group 1 had a cystic cavity involving the dorsal and partial involvement of the dorsolateral funiculi. A larger cavity, involving the dorsal, dorsolateral funiculi and the gray matter of the dorsal and ventral horns was found in group 2. In group 3, most of the spinal cord was destroyed and only a thin rim of tissue remained. Conclusion : The results of this study show that the photochemical graded ischemic SCI model. described in rats, can be successfully adapted to mice, in a reliable and reproducible manner. The functional deficits are correlated an increase in the irradiation time and, therefore, to the severity of the injury. The photothrombotic model of SCI, in mice with 20 mg/kg Rose bengal for 5 minutes illumination, provides an effective model that could be used in future research. This photochemical model can be used for investigating secondary responses associated with traumatic SCI.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.711-717
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• 2013

Opisthorchis viverrini (O. viverrini) is a well-known causative agent of cholangiocarcinoma (CCA) in humans. CCA is very resistant to chemotherapy and is frequently fatal. To understand the pathogenesis of CCA in humans, a rodent model was developed. However, the development of CCA in rodents is time-consuming and the xenograft-transplantation model of human CCA in immunodeficient mice is costly. Therefore, the establishment of an in vivo screening model for O. viverrini-associated CCA treatment was of interest. We developed a hamster CCA cell line, Ham-1, derived from the CCA tissue of O. viverrini-infected and N-nitrosodimethylamine-treated Syrian golden hamsters. Ham-1 has been maintained in Dulbecco's Modified Essential Medium supplemented with 10% fetal bovine serum for more than 30 subcultures. These cells are mostly diploid (2n=44) with some being polyploid. Tumorigenic properties of Ham-1 were demonstrated by allograft transplantation in hamsters. The transplanted tissues were highly proliferative and exhibited a glandular-like structure retaining a bile duct marker, cytokeratin 19. The usefulness of this for in vivo model was demonstrated by berberine treatment, a traditional medicine that is active against various cancers. Growth inhibitory effects of berberine, mainly by an induction of G1 cell cycle arrest, were observed in vitro and in vivo. In summary, we developed the allo-transplantable hamster CCA cell line, which can be used for chemotherapeutic drug testing in vitro and in vivo.

• Korean Journal of Forensic Psychology
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• v.13 no.2
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• pp.99-119
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• 2022

Research on sex offense has shown that sex offenders are very heterogeneous. Sex offenders are heterogeneous in their probability of risk of recidivism. Some sex offenders are known to be much higher in their tendencies to reactivate than others. The study examined the predictive and explanatory power of static and dynamic risk factors in STATIC-99 and HAGSOR-Dynamic which have been used in Korean correctional facilities since 2014. STATIC-99 and HAGSOR-Dynamic showed moderate predictive accuracy for all crimes(AUC = .737, AUC = .597, respectively, ps < .001). However, when examining sex crime alone, only STATIC-99 predicted recidivism significantly(AUC = .743, p < .001). The incremental predictive power of HAGSOR-Dynamic was confirmed; the explanatory power of Model 2 comprising both static and dynamic risk factors were significant beyond Model 1 comprising only static factors(∆χ²= 12.721, p < .001), but this tendency was only applied to the model of all crimes. These findings were discussed with implications of practicing the sex offender assessment and treatment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.2
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• pp.295-303
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• 2023

As the cloud computing market grows, a variety of cloud services are now reliably delivered. Administrative agencies and public institutions of South Korea are transferring all their information systems to cloud systems. It is essential to develop security solutions in advance in order to safely operate cloud services, as protecting cloud services from misuse and malicious access by insiders and outsiders over the Internet is challenging. In this paper, we propose a zero trust model for cloud storage services that store sensitive data. We then verify the effectiveness of the proposed model by operating a cloud storage service. Memory, web, and network forensics are also performed to track access and usage of cloud users depending on the adoption of the zero trust model. As a cloud storage service, we use Amazon S3(Simple Storage Service) and deploy zero trust techniques such as access control lists and key management systems. In order to consider the different types of access to S3, furthermore, we generate service requests inside and outside AWS(Amazon Web Services) and then analyze the results of the zero trust techniques depending on the location of the service request.

• Journal of Korea Water Resources Association
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• v.56 no.7
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• pp.439-449
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• 2023

Recent advancements in data measuring technology have facilitated the installation of various sensors, such as pressure meters and flow meters, to effectively assess the real-time conditions of water distribution systems (WDSs). However, as cities expand extensively, the factors that impact the reliability of measurements have become increasingly diverse. In particular, demand data, one of the most significant hydraulic variable in WDS, is challenging to be measured directly and is prone to missing values, making the development of accurate data generation models more important. Therefore, this paper proposes an adversarially trained autoencoder (ATAE) model based on generative deep learning techniques to accurately estimate demand data in WDSs. The proposed model utilizes two neural networks: a generative network and a discriminative network. The generative network generates demand data using the information provided from the measured pressure data, while the discriminative network evaluates the generated demand outputs and provides feedback to the generator to learn the distinctive features of the data. To validate its performance, the ATAE model is applied to a real distribution system in Austin, Texas, USA. The study analyzes the impact of data uncertainty by calculating the accuracy of ATAE's prediction results for varying levels of uncertainty in the demand and the pressure time series data. Additionally, the model's performance is evaluated by comparing the results for different data collection periods (low, average, and high demand hours) to assess its ability to generate demand data based on water consumption levels.

• Wind and Structures
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• v.25 no.1
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• pp.79-100
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• 2017

The use of wind energy resources is developing rapidly in recent decades. There is an increasing number of wind farms in high wind-velocity areas such as the Pacific Rim regions. Wind turbine towers are vulnerable to tropical cyclones and tower failures have been reported in an increasing number in these regions. Existing post-disaster failure case studies were mostly performed through forensic investigations and there are few numerical studies that address the collapse mode simulation of wind turbine towers under strong wind loads. In this paper, the wind-induced failure analysis of a conventional 65 m hub high 1.5-MW wind turbine was carried out by means of nonlinear response time-history analyses in a detailed finite element model of the structure. The wind loading was generated based on the wind field parameters adapted from the cyclone boundary layer flow. The analysis results indicate that this particular tower fails due to the formation of a full-section plastic hinge at locations that are consistent with those reported from field investigations, which suggests the validity of the proposed numerical analysis in the assessment of the performance of wind-farms under cyclonic winds. Furthermore, the numerical simulation allows to distinguish different failure stages before the dynamic collapse occurs in the proposed wind turbine tower, opening the door to future research on the control of these intermediate collapse phases.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.1
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• pp.61-68
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• 2015

In recent times, the median filtering (MF) detector as a forensic tool for the recovery of forgery images' processing history has concerned broad interest. For the classification of MF image, MF detector should be designed with smaller feature set and higher detection ratio. This paper presents a novel method for the detection of MF in altered images. It is transformed from BMP to several kinds of MF image by the median window size. The difference distribution values are computed according to the window sizes and then the values construct the feature set same as the MF window size. For the MF detector, the feature set transformed to the model specification which is computed using latent growth modeling (LGM). Through experiments, the test image is classified by the discriminant into two classes: the true positive (TP) and the false negative (FN). It confirms that the proposed algorithm is to be outstanding performance when the minimum distance average is 0.119 in the confusion of TP and FN for the effectivity of classification.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.1
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• pp.57-67
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• 2013

Lately, intrusive incidents (including system hacking, viruses, worms, homepage alterations, and data leaks) have not involved the distribution of an virus or worm, but have been designed to acquire private information or trade secrets. Because an attacker uses advanced intelligence and attack techniques that conceal and alter data in a computer, the collector cannot trace the digital evidence of the attack. In an initial incident response first responser deals with the suspect or crime scene data that needs investigative leads quickly, in accordance with forensic process methodology that provides the identification of digital evidence in a systematic approach. In order to an effective initial response to first responders, this paper analyzes the collection data such as user usage profiles, chronology timeline, and internet data according to CFFPM(computer forensics field triage process model), proceeds to design, and implements a collection application to deploy the client/server architecture on the Windows based computer.

• Journal of Oral Medicine and Pain
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• v.25 no.2
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• pp.253-263
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• 2000

We collected age determination cases which were done at Yonsei university dental hospital, department of oral medicine from 1976 to 1999 to analyze it's tendency among Koreans. We analyzed 435 clients cases which were stored by age estimation program from January 1993 to December 1999. The results are as follows: 1. There were no significant difference in the sexual distribution (male : 52.0%, female : 48.0%) and more than half percent (51%) were 20's and 30's. 2. Among the age determination clients, those who wanted to decrease their age (50.3%) and those who wanted to increase their age (49.7%) shows similar in number. And the former case were predominant in the female clients, but the latter case in the male clients. Also the clients below six years of age were predominant in the former case, but the clients more than sixty were predominant in the latter case. 3. The purposes of age correction showed different distribution for ages: job or employment for 20's and 30's, marriage for 20's, registration for school for below six, welfare and other social services for 50 and older. 4. Age was estimated by Nolla's growth stage for 12 and under, calcification of the second and third molar for 12~20, and for 20 and over, Takei's tooth abrasion model was used. 5. The alleged age was in accordance with the documents and other information given by clients, but in the 20.6% of the estimation cases, the alleged age was discarded. In the results of the analysis of age determination cases in Koreans, many of the cases resulted from our historical turbulence and social distinctiveness, causing an increase in the necessity for age correction in each age group. For more accurate determination for each age group, further studies with Koreans must be done continuously.

• BMB Reports
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• v.54 no.10
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• pp.528-533
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• 2021

Osteoarthritis (OA) is a degenerative disorder that can result in the loss of articular cartilage. No effective treatment against OA is currently available. Thus, interest in natural health products to relieve OA symptoms is increasing. However, their qualities such as efficacy, toxicity, and mechanism are poorly understood. In this study, we determined the efficacy of avenanthramide (Avn)-C extracted from oats as a promising candidate to prevent OA progression and its mechanism of action to prevent the expression of matrix-metalloproteinases (MMPs) in OA pathogenesis. Interleukin-1 beta (IL-1β), a proinflammatory cytokine as a main causing factor of cartilage destruction, was used to induce OA-like condition of chondrocytes in vitro. Avn-C restrained IL-1β-mediated expression and activity of MMPs, such as MMP-3, -12, and -13 in mouse articular chondrocytes. Moreover, Avn-C alleviated cartilage destruction in experimental OA mouse model induced by destabilization of the medial meniscus (DMM) surgery. However, Avn-C did not affect the expression of inflammatory mediators (Ptgs2 and Nos) or anabolic factors (Col2a1, Aggrecan, and Sox9), although expression levels of these genes were upregulated or downregulated by IL-1β, respectively. The inhibition of MMP expression by Avn-C in articular chondrocytes was mediated by p38 kinase and c-Jun N-terminal kinase (JNK) signaling, but not by ERK or NF-κB. Interestingly, Avn-C added with SB203580 and SP600125 as specific inhibitors of p38 kinase and JNK, respectively, enhanced its inhibitory effect on the expression of MMPs in IL-1β treated chondrocytes. Taken together, these results suggest that Avn-C is an effective candidate to prevent OA progression and a natural health product to relieve OA pathogenesis.