• Journal of Information Processing Systems
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• v.15 no.3
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• pp.570-592
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• 2019

The Event-B design pattern is an excellent way to quickly develop a formal model of the system. Researchers have proposed a number of Event-B design patterns, but they all lack formal behavior semantics. This makes the analysis, verification, and simulation of the behavior of the Event-B model very difficult, especially for the control-intensive systems. In this paper, we propose a novel method to transform the Event-B synchronous control flow design pattern into the labeled transition system (LTS) behavior model. Then we map the design pattern instantiation process of Event-B to the instantiation process of LTS model and get the LTS behavior semantic model of Event-B model of a multi-level complex control system. Finally, we verify the linear temporal logic behavior properties of the LTS model. The experimental results show that the analysis and simulation of system behavior become easier and the verification of the behavior properties of the system become convenient after the Event-B model is converted to the LTS model.

• Journal of Mechanical Science and Technology
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• v.20 no.8
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• pp.1275-1283
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• 2006

Condensation heat transfer coefficients in a 7.92 mm inside diameter copper smooth tube were obtained experimentally for R22, R134a, and R410A. Working conditions were in the range of $30-40^{\circ}C$ condensation temperature, $95-410 kg/m^2s$ mass flux, and 0.15-0.85 vapor quality. The experimental data were compared with the eight existing correlations for an annular flow regime. Based on the heat-momentum analogy, a condensation heat transfer coefficients correlation for the annular flow regime was developed. The Breber et al. flow regime map was used to discern flow pattern and the Muller-Steinhagen & Heck pressure drop correlation was used for the term of the proposed correlation. The proposed correlation provided the best predicted performance compared to the eight existing correlations and its root mean square deviation was less than 8.7%.

• Journal of Power System Engineering
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• v.18 no.3
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• pp.79-86
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• 2014

Mixed convective vortex flow in the three-dimensional rectangular channel filled with high viscous fluid(Pr=909) is investigated computationally under various operating conditions. The Reynolds number is varied from 0 to $5{\times}10^{-1}$, the Rayleigh number from $10^3$ to $5{\times}10^4$. The three-dimensional governing equations are discretized using the finite volume method. The effects of Reynolds number and Rayleigh number are presented and discussed. From a parametric study, it is found that vortex flow pattern of mixed convection in rectangular channels can be classified into three flow patterns basically, but the new vortex flow structures containing wave rolls are found, which are affected by Rayleigh number and Reynolds number. From this results, we can draw a flow regime map to delineate various vortex flow patterns in the high viscosity fluid mixed convective flow.

• The Journal of the Petrological Society of Korea
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• v.26 no.2
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• pp.153-163
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• 2017

The Naeyeonsan Tuff is a stratigraphic unit which is distinguished as a cooling unit in the volcanic rocks of the northern Pohang. The Naeyeonsan Tuff, which is composed of crystals of plagioclase, quartz and hornblende, glasses of pumice and shard, and lithics of dacite, rhyolite, sandstone and shale, belongs to a lapilli tuff field according to the granulometric classification and to a vitric tuff field according to the constituent classification. The tuffs mostly develop welding foliations by dense welding and flatterning pumices and shards, and show several flow indicators by pyroclastic flowing. We can know a movement pattern from flow lineations and imbrications by pumices and lithics, and lateral gradings in isopleth map by average largest lithics and pumices in the Naeyeonsan Tuff, which indicate that the Naeyeonsan Tuff had a possible source area from the southeastern part.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.203-213
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• 2008

Benthic macro invertebrate communities were collected at six different sampling sites in the Musucheon stream in Korea from July 2006 to July 2007, and ecological exergy values were calculated based on five different functional feeding groups (collector-gatherer, collector-filterer, predator, scrapper, and shredder) of benthic macro invertebrates. Each sampling site was categorized to three stream types (perennial, intermittent and drought) based on the water flow condition. Exergy values were low at all study sites right after a heavy rain and relatively higher in the perennial stream type than in the intermittent or the drought stream type. Self-Organizing Map (SOM), unsupervised artificial neural network, was implemented to pattern spatial and temporal dynamics of ecological exergy of the study sites. SOM classified samples into four clusters. The classification reflected the effects of floods and droughts on benthic macroinvertebrate communities, and was mainly related with the stream types of the sampling sites. Exergy values of each functional feeding group also responded differently according to the different stream types. Finally, the results showed that exergy is an effective ecological indicator, and patterning changes of exergy using SOM is an effective way to evaluate target ecosystems.

• Journal of The Korean Association For Science Education
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• v.24 no.2
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• pp.246-257
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• 2004

The purpose of this qualitative study was to identify high school students' conceptual differentiation patterns on human digestion system. The subjects were 124 high school students and this group was guided to independently construct concept maps. Among them, 19 were selected for an in-depth interview and a short test. The concept maps, interview transcripts and the results of short-test were analyzed to identify conceptual differentiation patterns. The results were as follows. Mainly three distinct conceptual differentiation patterns were identified. The first pattern can be named as an 'Free-flow type'. The group belongs to this pattern expressed numerous examples than meaningful concepts with unclear understanding of hierarchial relation between each concepts. Also, this group had difficulties in grasp interrelations of different concepts. The second pattern can be identified as 'Sequence type'. This group constructed concept maps by featuring conceptual sequence. The group applied meaningful learning, yet assembled concept maps primarily according to sequence of learning and exhibited less organized concept maps than hierarchial type. The third pattern can be named as 'Hierarchial type'. All students elaborated concept maps after lessons. The sequence type changed hierarchial type or sequence mixed with hierarchial type but free-flow type was hardly changed.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.145-152
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• 1997

A coupling of two-dimensional model and GIS technique is applied to simulate sediment transport analysis. Accurate transformations are performed for the data which have various reduced scales. Basic maps are discretized the mesh of true scale for the finite element model by using the digital map and the Traverse Mercator coordinate. Under $200m^3/s$ flow rate condition, velocity vectors, depth contours, velocity contours and deposition contours are Presented for the 5km reach of midstream of Keum River from confluence of Ji-chun to Baekche Bridge. The simulation results of the study agree well with those of one-dimensional varied flow analysis and observed data. The flow and deposition pattern revealed a meandering characteristics of the river qualitatively.

• International Journal of Contents
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• v.15 no.4
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• pp.8-15
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• 2019

This paper presents a solution of the 'Quick, Draw! Doodle Recognition Challenge' hosted by Google. Doodles are drawings comprised of concrete representational meaning or abstract lines creatively expressed by individuals. In this challenge, a doodle is presented as a sequence of sketches. From the view of at the sketch level, to learn the pattern of strokes representing a doodle, we propose a sequential model stacked with multiple convolution layers and Long Short-Term Memory (LSTM) cells following the attention mechanism [15]. From the view at the image level, we use multiple models pre-trained on ImageNet to recognize the doodle. Finally, an ensemble and a post-processing method using the minimum cost flow algorithm are introduced to combine multiple models in achieving better results. In this challenge, our solutions garnered 11th place among 1,316 teams. Our performance was 0.95037 MAP@3, only 0.4% lower than the winner. It demonstrates that our method is very competitive. The source code for this competition is published at: https://github.com/ngxbac/Kaggle-QuickDraw.

• International Journal of Advanced Culture Technology
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• v.9 no.2
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• pp.80-85
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• 2021

This study is to analyze the structure of the networks of tourism marketing on Twitter, identifying the most prominent users, the flow of information about tourism marketing, and the interaction between the users posting tweets. This study employs NodeXL pro as a visualization software package for social network analysis. The number of vertices or nodes is 171, and the number of the unique edges or links is 128, but there are 101 edges with duplicates, so the total links are 229, which means that there are fewer Twitter accounts in the social network on tourism marketing, but they have a few close relationships by sharing information. The research can map the social network of communicators of tourism marketing using Twitter data. The network has a complicated pattern, including one independent network and some connected networks. Some mediators connect each network and can control the information flow of tourism marketing. More communicators are getting the information than the ones providing it, which means that there is likely to be the dependence of information among communicators that can cause an obstacle and distortion of the information flow system, especially in the independent network.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.134-137
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• 2004

본 논문에서는 향후 남한의 예비력 중대방안으로 동북아 지역 (러시아, 중국, 몽고, 북한, 한국, 일본)의 지역의 전력계통연계선로의 구성 및 동북아 지역의 계절별 패턴을 고려한 조류계산을 수행하여 전력수급의 분포도를 파악하고자 한다. 특히 한반도 전체의 전력수급을 고려하여 볼 때 남-북한의 수도권 및 영남 지역의 두 지역은 향후 계속적인 전력 수요의 증가로 인한 발전력의 부족상태가 계속되리라 여겨지며, 이러한 문제의 해결방안으로 북한의 신포지역에 2,000MW KEDO 경수로를 건설하여 공급하는 방안이 있겠으나 현재 여러 가지 정치적 상황으로는 건설을 중단하게 되었다. 이러한 정치적 상황의 변화로 다른 대안이 필요하게 되었다. 이들 중의 하나가 극동러시아나 시베리아 및 중국 그리고 일본과의 연계에 의한 예비력을 확보하는 방안이 될 것이다. 본 논문에서는 동북아 지역과 연계를 할 수 있는 가능한 지역을 고려하여 연계선로를 구성하고 계절별 효과를 고려한 조류계산을 실시하여 연계 시 융통전력의 분포도를 연구하고자 한다.