• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.482-488
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• 2017

Recently, weapon system has been highly regarding IM ability. Explosive is positively necessary in weapon system and it is principle component that must be improved for IM as the most hazardous material. RDX is one of energetic materials used the most at present since 1930s. It is being applied a lot to most of explosive in warhead and artillery and rocket propellants in these latter days due to its low cost and high energetic characteristics. However, it has a disadvantage which is more sensitive than some insensitive explosive like NTO, DADNE recently developed. To overcome this, researches have been continued about insensitive RDX and we are performing the study as well. In this study, we developed to apply reduced sensitivity RDX to pilot scale and mass production and we could confirm a result by shock sensitivity test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1078-1087
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• 2014

In the conventional centralized mobility management schemes, it can lead to single points of failure, occurrence of a bottleneck, since all data and control are concentrated on the mobility anchor which is located in home network. In the current research of distributed mobility management, it is doing research into distributed mobility management which is supported by distributed mobility anchors. Such schemes do not consider a failure of the mobility anchor. However, it could be an issue under tactical environment since it occur non-service problem due to anchor movement, maintenance, failure, etc. In this paper, we proposed new DMM scheme named T-DMM(Tactical-Distributed Mobility Management) which can support handover even if mobility anchor breaks down. From the numerical analysis, we evaluate signaling cost and handover latency.

• Journal of KIISE
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• v.42 no.1
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• pp.122-129
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• 2015

This paper proposes a method for providing the information about multimedia streams for telepresence services to heterogeneous services such as IMS (IP Multimedia Subsystem) and RTCWeb (Real-Time Communication in WEB-browsers). First of all, we design an interworking gateway for each service and suggest a procedure for providing the information about multimedia streams, which is defined by CLUE, a working group for standardization, to the heterogeneous services. We also apply the method of the actual CLUE information exchange and implement it in our experiment environment. Finally, we show that the proposed method can exchange more information than previous methods even though the media session re-establishment time is similar to legacy systems in terms of performance analysis. With the proposed method, the heterogeneous services can collect a variety of information about the telepresence service and use it according to user preference. In this way it provides rich multimedia streaming services for many areas.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.5
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• pp.654-666
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• 2019

The tactical network has several different characteristics compared with commercial internet network such as hierarchical topology, dynamic topology changing and wireless link based connectivity. For considering IP mobility management in the tactical network, current mobility management using Mobile IP(MIP) is not suitable with some reasons such as non-optimal routing paths and single point of failure. Proxy Mobile IP(PMIP) which supporting network-based mobility in hierarchical manner can provide optimal routing path in the tactical network environment, but centralized anchor is still remained a threat to the stability of the tactical network which changes its topology dynamically. In this paper, we propose PMIP-based distributed mobility management for the tactical network environment. From our design, routing paths are always configured in optimized way, as well as path is recovered quickly when the mobility anchor of user is failed. From numerical analysis, comparing to other mobility scheme, result shows that the proposed scheme can reduce packet transmission cost and latency in tactical network model.

• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.171-177
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• 2019

Smart farm is a breakthrough technology that can maximize crop productivity and economy through efficient utilization of space regardless of external environmental factors. This study was conducted to investigate the optimal growth and physiological conditions of Chinese matrimony vine (Lycium chinense) with LED light sources in a smart farm. The light source was composed of red+blue and red+blue+white mixed light using a LED system. In the red+blue mixed light, red and blue colored LEDs were mixed at ratios of 1:1, 2:1, 5:1, and 10:1, with duty ratios varied to 100%, 99%, and 97%. The experimental results showed that the photosynthetic rate according to the types of light sources did not show statistically significant differences. Meanwhile, the photosynthetic rate according to the mixed ratio of the red and the blue light was highest with the red light and blue LED ratio of 1:1 while the water use efficiency was highest with the red and blue LED ratio of 2:1. The photosynthetic rate according to duty ratio was highest with the duty ratio of 99% under the mixed light condition of red+blue+white whereas the water use efficiency was highest with the duty ratio of 97% under the mixed light of red+blue LED. The results indicate that the light source and light quality for the optimal growth of Lycium chinense in the smart farm using the LED system are the mixed light of red+blue (1:1) and the duty ratio of 97%.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.1167-1187
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• 2020

We are facing the situation where cyber threats such as hacking, malware, data leakage, and theft, become an important issue in the perspective of personal daily life, business, and national security. Although various efforts are being made to response to the cyber threats in the national and industrial sectors, the problems such as the industry-academia skill-gap, shortage of cybersecurity professionals are still serious. Thus, in order to overcome the skill-gap and shortage problems, we propose a Cybersecurity technical response Job Competency(CtrJC) framework by adopting the concept of cybersecurity personnel's job competency. As a sample use-case study, we implement the CtrJC against to personals who are charged in realtime cybersecurity response, which is an important job at the national and organization level, and verify the our framework's effects. We implement a sample model, which is a CtrJC against to realtime cyber threats (We call it as CtrJC-R), and study the verification and validation of the implemented model.

• Journal of the Korea Computer Graphics Society
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• v.30 no.3
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• pp.51-59
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• 2024

Collecting a dataset with a corresponding labeled gaze vector requires a high cost in the gaze estimation field. In this paper, we suggest a data augmentation of manipulating the gaze of an original image, which improves the accuracy of the gaze estimation model when the number of given gaze labels is restricted. By conducting multi-class gaze bin classification as an auxiliary task and adjusting the latent variable of the diffusion model, the model semantically edits the gaze from the original image. We manipulate a non-binary attribute, pitch and yaw of gaze vector to a desired range and uses the edited image as an augmented train data. The improved gaze accuracy of the gaze estimation network in the semi-supervised learning validates the effectiveness of our data augmentation, especially when the number of gaze labels is 50k or less.

• Korean journal of communication and information
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• v.81
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• pp.272-298
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• 2017

This study aims at understanding Korean fans who are also one of the most inquisitive consumers of the Korean pop products. For this purpose, it examines how Korean fandom perceives the procedures of the K-pop's globalization and constructs different perspectives of foreign fans. Firstly, it examines Korean fandom's the national pride as the K-pop expands to the global markets. Secondly, it explores how the Korean fandom rationalizes its possessive instinct while the global fans and markets becomes increasingly important. Finally, it explores how the Korean fandom constructs the different perceptions on foreign fans. In order to observe korean fans' thoughts and activities, it participates in the interactions in the tweeters and an online community. The Korean fans' perspective reflects both on individual tastes and the social dimensions in which fans live through. Through the lens of the Korean fandom, this study attempts to explicate the Korean fans' perception on foreign fans, which reflects another dimension of the K-pop's globalization.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.438-453
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• 2019

Background: To investigate the trends of succession occurring at the Pinus thunbergii forests on the lowlands of Jeju Island, we quantified the species compositions and the importance values by vegetation layers of Braun-Blanquet method on the Pinus thunbergii forests. We used multivariate analysis technique to know the correlations between the vegetation group types and the location environmental factors; we used the location environment factors such as altitudes above sea level, tidal winds (distance from the coast), annual average temperatures, and forest gaps to know the vegetation distribution patterns. Results: According to the results on the lowland of Jeju Island, the understory vegetation of the lowland Pinus thunbergii forests was dominated by tall evergreen broad-leaved trees such as Machilus thunbergii, Neolitsea sericea, and Cinnamomum japonicum showing a vegetation group structure of the mid-succession, and the distribution patterns of vegetation were determined by the altitudes above sea level, the tidal winds on the distance from the coast, the annual average temperatures, and the forest gaps. We could discriminate the secondary succession characteristics of the Pinus thunbergii forests on the lowland and highland of Jeju Island of South Korea. Conclusions: In the lowland of Jeju Island, the secondary succession will progress to the form of Pinus thunbergii (early successional species)→Machilus thunbergii, Litsea japonica (mid-successional species)→Machilus thunbergii (late-successional species) sequence in the temperate areas with strong tidal winds. In the highland of Jeju Island, the succession will progress to the form of Pinus thunbergii (early successional species)→Neolitsea sericea, Eurya japonica (mid-successional species)→Castanopsis sieboldii (late-successional species) sequence in the areas where tidal winds are weak and temperatures are relatively low. However, local differences between lowland and highland of Jeju Island will be caused by the micro-environmental factors resulting from the topographic differences and the supply of tree seeds. From the characteristics of succession study, we could properly predict and manage the Pinus thunbergii forest ecosystem on lowland and highland of Jeju Island.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.3
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• pp.266-271
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• 2014

This study was performed to evaluate the relationship between the types of maxillary labial frenum attachment and the dental age in children. The maxillary labial frenum attachment levels were examined from the children who visited Chonbuk National University Dental Hospital between April, 2010 and December, 2013. The total number of the examined children was 320 (160 males, 160 females) between the age of 2 and 12. The types of maxillary labial frenum were categorized according to Placek's classification and each type was analyzed for its relationship with both Hellman's dental age and the eruption stage of permanent maxillary anterior teeth. The observed forms of maxillary labial frenum along with their frequency were as follows: gingival (56.3%), papillary (20.6%), mucosal (18.1%) and papillary penetrating (5.0%). The frenum form showed no significant difference due to gender (p > 0.05). From IC to IIIB in Hellman's dental age, the mucosal type increased significantly (p < 0.001). There was no significant relationship between the types of maxillary labial frenum attachment and the eruption state of permanent maxillary anterior teeth (p > 0.05).