The design of a wooden impact limiter equipped to a transportation cask for radioactive materials was optimized. According to International Atomic Energy Agency Safety Standards, 9 m drop tests should be performed on the transportation cask to evaluate its structural integrity in a hypothetical accident condition. For impact resistance, the size of the impact limiter should be properly determined for the impact limiter to absorb the impact energy and reduce the impact force. Therefore, the design parameters of the impact limiter were optimized to obtain a feasible optimal design. The design feasibility criteria were investigated, and several objectives were defined to obtain various design solutions. Furthermore, a probabilistic approach was introduced considering the uncertainties included in an engineering system. The uncertainty of material properties was assumed to be a random variable, and the probabilistic feasibility, based on the stochastic approach, was evaluated using reliability. Monte Carlo simulation was used to calculate the reliability to ensure a proper safety margin under the influence of uncertainties. The proposed methodology can provide a useful approach for the preliminary design of the impact limiter prior to the detailed design stage.

Elite trees of evergreen oaks (Quercus glauca, Quercus acuta, Quercus salicina, and Quercus gilva) were selected from Jeju Island and Wando Island. Elite trees were carried out by modifying the tree selection criteria. Elite trees were selected by height, DBH, clear length, crown diameter, leaf length, and leaf depth. Regarding height, Q. acuta was the highest, and the other three tree species were similar. Clear length showed the same trend as height. In the case of Q. glauca, height showed a positive correlation with DBH, crown diameter and leaf depth. In the case of Q. acuta, positive correlations were shown with all characteristics of DBH, and correlation analysis between DBH and crown diameter, and leaf length and leaf depth also showed positive correlations. In the Pearson correlation coefficient of Q. salicina, height showed a positive correlation with DBH. In the case of Q. gilva, height showed a positive correlation with DBH (0.539). As a result of analyzing the principal components for each of the six growth characteristics, the four species were divided into two principal components with an eigenvalue of 1 or higher, and the cumulative explanatory power was 57% or more. Based on the principal component results, it was possible to confirm the relationship between growth and trait characteristics by species. Still, it was not easy to understand the relationship among each selection tree, so a cluster analysis was performed using the principal component score. Based on the distance levels 5.0 and 6.0 of the selection tree of each species, they were classified into 4-5 clusters. It is judged that the above results can be used as data for the selection of elite trees of evergreen oaks.

오늘날 게임 산업은 지속적으로 성장하고 있는 추세이다. 이런 배경에서 게임 이용자들은 다양한 게임 장르를 경험하고 있으며, 또한 게임 내의 승률을 높이기 위한 다양한 활동에 많은 관심을 가지고 있다. 게임 이용자 들은 자신이 즐기는 게임 캐릭터들의 승률 및 픽률과 같은 다양한 정보들을 인터넷 검색을 통해 수집하고 있 으며, 그에 따라 자신이 즐기는 게임 플레이어의 밸런스에 관해서 많은 관심을 나타내고 있다. 본 연구자는 밸런스 관련 다양한 연구를 탐색하는 과정에서 게임 속의 밸런스를 맞추는 기준이 있다면, 또한 그 기준에 대 한 예측이 가능하다면 그 기준을 중심으로 이용자들의 다양한 밸런스 패치 활용 및 게임 전략 수립에 도움이 될 수 있을 것으로 판단하였다. 본 연구에서는 플레이어들의 밸런스 패치가 중요하게 인식되고 있는 MOBA 장르 게임을 중심으로 밸런스 패치 예측 기준을 수립하는 데 초점을 맞추었다. 특별히 밸런스 패치를 진행할 때 캐릭터들의 특성 및 개발자의 패치 코멘트, 그리고 승률 및 픽률 변화에 따른 이후 패치 로드맵까지 고려 할 수 있는 체계를 제시한 점에서 큰 의의가 있다고 볼 수 있다. 이를 통해 개발자는 플레이어들의 밸런스를 더 쉽게 맞출 수 있도록 유도하고, 플레이어는 밸런스 패치를 예측하여 더욱 효율성 있는 게임 전략을 실행할 수 있도록 유도하여 MOBA 장르 게임의 이해관계자 모두에게 도움이 되는 정보를 전달할 것이다.

Background: Although rectus femoris (RF) eccentric training and static stretching (SS) have been reported effectively on lumbar flexibility, and muscle architecture, most studies are results using machines and long-term effects. Therefore, we want to investigate the effect of Reverse Nordic Hamstring Exercise (RNHE), a self-eccentric training, by immediately comparing it with SS. Objectives: To compare the RNHE and SS of RF to show the effects of lumbar flexibility, and fascicle length (FL). Design: Randomized controlled trial. Methods: A total of 30 study subjects were randomly allocated into an experimental group(Reverse Nordic Hamstring Exercise) and a control group(Static Stretching). Before and after the intervention, the subject performed fingertip to floor test (FFT) to evaluate the flexibility of the lumbar spine and measured FL through the SONON 300L (Healcerion Inc., Seoul, South Korea). Results: There was a significant effect on lumbar flexibility within both groups (P<.05), also there were clear results between the two groups (P<.05). FL showed a significant increase in RNHE (P<.05), but not in SS, and there was a no significant difference between the two groups. Conclusion: RNHE is effective in improving lumbar flexibility, and FL of RF muscle.

Despite evidence that bacteria-sensing Toll-like receptors (TLRs) are activated in salivary gland tissues of Sjogren syndrome (SS) patients, the role of oral bacteria in SS etiopathogenesis is unclear. We previously reported that two SS-associated oral bacteria, Prevotella melaninogenica (Pm) and Rothia mucilagenosa (Rm), oppositely regulate the expression of major histocompatibility complex class I (MHC I) in human salivary gland (HSG) cells. Here, we elucidated the mechanisms underlying the differential regulation of MHC I expression by these bacteria. The ability of Pm and Rm to activate TLR2, TLR4, and TLR9 was examined using TLR reporter cells. HSG cells were stimulated by the TLR ligands, Pm, and Rm. The levels of MHC I expression, bacterial invasion, and viability of HSG cells were examined by flow cytometry. The hypoxic status of HSG cells was examined using Hypoxia Green. HSG cells upregulated MHC I expression in response to TLR2, TLR4, and TLR9 activation. Both Pm and Rm activated TLR2 and TLR9 but not TLR4. Rm-induced downregulation of MHC I strongly correlated with bacterial invasion and cell death. Rm-induced cell death was not rescued by inhibitors of the diverse cell death pathways but was associated with hypoxia. In conclusion, Pm upregulated MHC I likely through TLR2 and TLR9 activation, while Rm-induced hypoxia-associated cell death and the downregulation of MHC I, despite its ability to activate TLR2 and TLR9. These findings may provide new insight into how oral dysbiosis can contribute to salivary gland tissue damage in SS.

In weapon assignment studies to defend against threats such as ballistic missiles and long range artillery, threat assessment was partially lacking in analysis of various threat attributes, and considering the threat characteristics of warheads, which are difficult to judge in the early flight stages, it is very important to apply more reliable optimal solutions than approximate solution using LP model, Meta heuristics Genetic Algorithm, Tabu search and Particle swarm optimization etc. Our studies suggest Generic Rule based threat evaluation and weapon assignment algorithm in the basis of various attributes of threats. First job of studies analyzes information on Various attributes such as the type of target, Flight trajectory and flight time, range and intercept altitude of the intercept system, etc. Second job of studies propose Rule based threat evaluation and weapon assignment algorithm were applied to obtain a more reliable solution by reflection the importance of the interception system. It analyzes ballistic missiles and long-range artillery was assigned to multiple intercept system by real time threat assessment reflecting various threat information. The results of this study are provided reliable solution for Weapon Assignment problem as well as considered to be applicable to establishing a missile and long range artillery defense system.

As a semi-enclosed sea, the Yellow Sea is shared by costal states such as China, South Korea and North Korea which have common interests in this maritime area. This situation requires special attention and mutual efforts for the protection and preservation of the coastal waters and marine ecosystem. The Yellow Sea contains many shipping routes, and it is potentially exposed to the risks of vessel-source pollution. This research has examined how the Yellow Sea states have implemented the International Maritime Organisation conventions relating to vessel-source pollution at the domestic level through a comparative legal study. The objective of this research is to understand current national laws of the Yellow Sea states dealing with the prevention of vessel-source pollution and to emphasize the necessity of regional efforts and cooperation to implement global regulatory instruments in order to protect and preserve the marine environment from the threats of international shipping activities.