• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.148-159
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• 2020

This study investigated the seasonal and inter-annual changes in vertical distribution and size spectrum of walleye pollock, Gadus chalcogrammus inhabiting middle eastern coast of Korea (hear after pollock). Pollock was distributed between 50 m and 600 m depth range, and body size (total length) ranged from 16.6 cm to 81.5 cm. The trends of population body size were increased in autumn and winter and decreased in spring and summer. Vertical distribution of pollock showned depth-dependent patterns with distributing smaller individuals mainly in the upper layer (shallower depth), while larger fish in deeper habitats. Those patterns in vertical distribution of pollock population is probably due to be the results of energy-saving strategy, metabolic effects, and changes in prey selections according to pollock growth, derived from spatial and temporal changes in oceanic condition in habitat grounds. When water temperature in upper layer were increased and that of below thermocline depth became decreased in 2017, the ratio of smaller (<35 cm) and larger (≥35 cm) individuals was biased toward larger fishes, extending their distribution into shallow depth, and consequently main fishing ground was formed in far from coastal area. In addition, the ratio of smaller individual distributing between 100~300 m was increased with decreasing temperature gradient between below thermocline and bottom layer. Changes in spatial and temporal distributions of pollock population likely be related with vertical and horizontal changes in oceanic conditions and, consequently food supplies.

• Journal of Korean Association for Spatial Structures
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• v.19 no.4
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• pp.45-52
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• 2019

The purpose of the paper is to introduce a system that reduces the occurrence of weak-story in the event of earthquake. Weak-story concentrates deformation on the story and causes all member to collapse before the capacity of all member is reached. This paper introduces Strong-Back system (SB) to protect weak story. SB is a hybrid of zipper frame, tied eccentrically braced frame, and elastic truss system and it is divided into elastic and inelastic areas. Elastic areas prevent the generation of weak story by distributing energy, and inelastic areas dissipate energy through buckling or yielding. In this paper, the seismic performance is evaluated by comparing the four type braced frame with SB through push-over analysis. The four criteria are compared from the base shear, the ductility capacity, the column failure order, and the quantity of brace. As a result, SB proved to have sufficient performance to protect the weak-story.

• Proceedings of the KSRS Conference
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• 1998.09a
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• pp.280.2-286
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• 1998

Flood is the main natural disaster mostly in the world. It is a care problem to prevent flood disaster generally. The frequency of flood disaster is high and the distributing field is wide, the 50 percent population and 70 percent properties distribute at the threaten field of flood disaster in China. Flood disaster has caused a huge amount of economical losses and these losses have an increasing trend. Along with the development of reducing natural disaster action, it has become one of the most attentive problems for monitoring flood, preventing flood and forecasting flood efficiently. Remote sensing has the characteristics of large spatial observing areas, wide spectrum ranges, and imaging far away from the targets, imaging capabilities all weather. Spatial remote sensing information, which records the full, processes of the disaster's occurrence and development in real-time. It is a scientific basis for management, planning and decision-making. Through systemic analyzing the RS monitoring theory, based on compounding RS information, the technology and method of monitoring flood disaster are studied.

• Journal of Computational Design and Engineering
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• v.2 no.3
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• pp.183-194
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• 2015

This paper proposes a novel method for visualizing the thickness and clearance of 3D objects in a polyhedral representation. The proposed method uses the distance field of the objects in the visualization. A parallel algorithm is developed for constructing the distance field of polyhedral objects using the GPU. The distance between a voxel and the surface polygons of the model is computed many times in the distance field construction. Similar sets of polygons are usually selected as close polygons for close voxels. By using this spatial coherence, a parallel algorithm is designed to compute the distances between a cluster of close voxels and the polygons selected by the culling operation so that the fast shared memory mechanism of the GPU can be fully utilized. The thickness/clearance of the objects is visualized by distributing points on the visible surfaces of the objects and painting them with a unique color corresponding to the thickness/clearance values at those points. A modified ray casting method is developed for computing the thickness/clearance using the distance field of the objects. A system based on these algorithms can compute the distance field of complex objects within a few minutes for most cases. After the distance field construction, thickness/clearance visualization at a near interactive rate is achieved.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.74-76
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• 2000

공간 데이터와 같은 대용량의 데이터를 처리하는 시스템이나 다수의 클라이언트의 요구가 발생하는 시스템에서는 데이터에 대한 처리 비용 및 전용 비용으로 인한 서버 사이드의 병목 현상 및 질의 처리 속도의 저하라는 문제점을 갖는다. 본 논문에서는 이러한 문제점을 개선하기 위한 방법으로 미들웨어인 C-C Connector의 Method 및 프로토콜을 제안한다. 제안하는 C-C(Client To Client) Connector는 질의의 분석과 CIT(Client Information)의 검색을 통하여 인접한 클라이언트들의 캐쉬 데이터를 이용한 질의 처리의 가능 여부를 판단하며 인접 클라이언트와 요구 클라이언트 사이의 Connection을 형성함으로서 클라이언트-클라이언트의 질의 처리 및 데이터 전송 기능을 지원한다. 그리고 이러한 기능의 지원을 위한 서버, C-C Connector, 클라이언트 사이에서 수행되어지는 질의 처리의 프로토콜을 정의한다. 제안된 C-C Connector의 Method 및 프로토콜은 서버 사이드의 처리 비용을 현재 서버에 접속중인 클라이언트들에게 분배함으로서 서버 사이드의 병목현상과 질의 처리 시간의 지연이라는 문제점을 개선할 수 있으며 클라이언트 사이드에서의 반응 속도의 향상과 현재 연결된 시스템의 처리 성능을 최대한 활용할 수 있다는 장점을 갖는다.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.317-320
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• 2007

This research focuses on a network based data distribution and visualization system of Multi-functional Tran-port SATellite (MTSAT). Institute of Industrial Science (IIS) and Institute of Earthquake Research Institute (ERI) both at University of Tokyo have been receiving, processing, archiving and distributing of MTSAT imagery with a direct receiving of High Rate Information Transmit (HRIT) since October 2006. A software package, mtsatgeo, is developed including radiometric correction, geometric correction and spatial subset, and they are available on a web-based data distribution and processing service accessed at http://webgms.iis.u-tokyo.ac.jp/.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.12a
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• pp.153-158
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• 2004

Nowadays, the demand of the output analyzed from the gridded data has been sharply increased as the remote sensing technologies and GIS related industry have been developed. Therefore, a metadata access system which fits the requirements of the users should be developed for better managing and utilizing gridded data. In this background, this study defined a common application schema through the analysis of the metadata built by numerous institutes based on the draft metadata standards proposed from the study which maily concentrated on establishing the standards of distributing metadata for the gridded data supported by ETRI at 2003. Also, XML based integrated system was developed to access metadata maintained by SaTReC as well as SIMC to facilitate more convenient data access for the grid data users. The results of the pilot system developed from this study can be expected to contribute to build an more efficient and enlarged integrated access system of the metadata for the gridded data.

• Journal of Ubiquitous Convergence Technology
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• v.1 no.1
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• pp.28-34
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• 2007

Tree-based reliable multicast protocols provide scalability by distributing error-recovery tasks among several repair nodes. These repair nodes perform local error recovery for their receiver nodes using the data stored in their buffers. We propose a packet loss patterns adaptive feedback scheduling scheme to manage these buffers in an efficient manner. Under our scheme, receiver nodes send NAKs to repair nodes to request packet retransmissions only when the packet losses are independent events from other nodes. At dynamic and infrequent intervals, they also send ACKs to indicate which packets can be safely discarded from the repair node's buffer. Our scheme reduces delay in error recovery because the requested packets are almost always available in the repair node's buffers. It also reduces the repair node's workload because (a) each receiver node sends infrequent ACKs with non-fixed intervals and (b) their sending times are fairly distributed among all the receiver nodes.

• Structural Engineering and Mechanics
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• v.85 no.1
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• pp.55-64
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• 2023

Energy-based seismic design and evaluation methods are promising to be involved in the next generation design codes. Accordingly, determining the distribution of earthquake input energy demand among floor levels is quite imperative in order to develop an energy-based seismic design procedure. In this paper, peak floor input energy demands are achieved from relative input energy response histories of several reinforced concrete (RC) frames. A set of 22 horizontal acceleration histories selected from recorded near-fault earthquakes and scaled in time domain to be compatible with the elastic acceleration design spectra of Turkish Seismic Design Code are used in time history analyses. The distribution of the computed input energy per mass values and the arithmetic means through the height of the considered RC frames are presented as a result. It is found that spatial distribution of input energy per mass is highly affected by the number of stories. Very practical yet consistent formulation of distributing the total input energy to story levels is achieved, as a most important contribution of the study.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.86-99
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• 2021

One of the methods to alleviate traffic congestion is to increase the efficiency of the roads by providing traffic condition information on road user and distributing the traffic. For this, reliability must be guaranteed, and quantitative real-time traffic speed prediction is essential. In this study, and based on analysis of traffic speed related to traffic conditions, historical data correlated with traffic flow were used as input. We developed an LSTM model that predicts speed in response to normal traffic conditions, along with a CNN-LSTM model that predicts speed in response to incidents. Through these models, we try to predict traffic speeds during the hour in five-minute intervals. As a result, predictions had an average error rate of 7.43km/h for normal traffic flows, and an error rate of 7.66km/h for traffic incident flows when there was an incident.