• The Journal of the Acoustical Society of Korea
• /
• v.36 no.1
• /
• pp.23-29
• /
• 2017

A concept of a VSA (Virtual Source Array) is the method for an acoustic spatio-temporal focus at a selected location in the outbound direction with respect to the VSA without the need of a probe source as combines a TRP (Time-Reversal Processing) and time-delay and beam-steering. However, in TRP using the VSA concept, it is limited to the critical angle and the short distances relevant to the VSA. In this paper, the waveguide invariant theory is applied to the VSA concept to refocus the received field at ranges greater other than the critical angle and the short ranges by shifting the focused field. The suggested method is verified via numerical simulation, and the results show that the robust acoustic focusing is achieved on the selected location regardless of the limitation on the conventional VSA concept.

• KIPS Transactions on Computer and Communication Systems
• /
• v.9 no.5
• /
• pp.113-120
• /
• 2020

KISTI(Korea Institute of Science and Technology Information) provides HPC(High Performance Computing) service to users of university, institute, government, affiliated organization, company and so on. The NURION, supercomputer that launched its official service on Jan. 1, 2019, is the fifth supercomputer established by the KISTI. The NURION has 25.7 petaflops computation performance. Understanding how supercomputing services are used and how researchers are using is critical to system operators and managers. It is central to monitor and analysis network traffic. In this paper, we briefly introduce the NURION system and supercomputing service network with security configuration. And we describe the monitoring system that checks the status of supercomputing services in real time. We analyze inbound/outbound traffics and abnormal (attack) IP addresses data that are collected in the NURION supercomputing service network for 11 months (from January to November 1919) using time series and correlation analysis method.

• Information Systems Review
• /
• v.19 no.1
• /
• pp.169-183
• /
• 2017

As global competition is heating up and product life cycle has been rapidly shortened, each company pursues a variety of competitive technology innovations through different means of innovation. In this study, we assume that open innovation can be a shift motive of the technology innovation paradigm of small and medium enterprises (SMEs) being beyond the limitations of R&D within a company. We analyze the process and content of open innovation and performance. In addition, we identify the problems generated in the open innovation process and analyze the ways to strengthen open innovation. This study is based on the investigations into the technological competitiveness of local SMEs. The innovation ecosystem is analyzed from the perspective of product/service innovation, organizational innovation, and marketing innovation. Situational analysis is presented on the relationship between the innovation capabilities of information and communication technology SMEs and innovation performance.

• Economic and Environmental Geology
• /
• v.57 no.2
• /
• pp.161-175
• /
• 2024

Aggregate typically refers to sand and gravel formed by the transportation of rocks in rivers or artificially crushed, constituting a core resource in the construction industry. Gyeongsangbuk-do, the largest administrative area in South Korea, produces various sources of gravel, including forest, land (excluding other sources), river, and crushed stone. As of 2022, it has extracted approximately 6.96 million cubic meters of aggregate, with permitted production totaling around 4.07 million cubic meters and reported production of about 2.88 million cubic meters. The aggregate demand in Gyeongsangbuk-do is estimated to be 12.39 million cubic meters according to the estimation method in Ready-Mix Concrete. From the supply perspective, about 120 extraction sites are operational, with most municipalities maintaining an appropriate balance between aggregate demand and supply. However, in some areas, there is inbound and outbound transportation of aggregate to neighboring regions. Regions with significant inbound and outbound aggregate transportation in Gyeongsangbuk-do are areas connected to Daegu Metropolitan City and Pohang City along the Gyeongbu rail line, showing a high correlation with population distribution. Gyeongsangbuk-do faces challenges such as population decline, aging rural areas, and insufficient balanced regional development. Analysis using GIS reveals these trends in gravel demand and supply. Currently in this study, Gyeongsangbuk-do meets its demand for aggregate through the supply of various aggregate sources, maintaining stable aggregate procurement. River and terrestrial aggregates may be sustained as short-term supply strategies due to the difficulty of longterm development. Considering the reliance on raw material supply for selective crushing, it suggests the need for raw material management to maintain stability. Gyeongsangbuk-do highlights quarries in the forest as an important resource for sustainable aggregate supply, advocating for the development of large-scale aggregate quarries as a long-term alternative. These research findings are expected to provide valuable insights for formulating strategies for sustainable management and stable utilization of aggregate resources.

• The KIPS Transactions:PartA
• /
• v.10A no.4
• /
• pp.389-396
• /
• 2003

InfiniBand technology is being accepted as the future system interconnect to serve as the high-end enterprise fabric for cluster computing. This paper presents the design and implementation of the InfiniBand system interconnect, focusing on an InfiniBand host channel adapter (HCA) based on dual ARM9 processor cores The HCA is an SoC tailed KinCA which connects a host node onto the InfiniBand network both in hardware and in software. Since the ARM9 processor core does not provide necessary features for multiprocessor configuration, novel inter-processor communication and interrupt mechanisms between the two processors were designed and embedded within the KinCA chip. Kinch was fabricated as a 564-pin enhanced BGA (Bail Grid Array) device using 0.18${\mu}{\textrm}{m}$ CMOS technology Mounted on host nodes, it provides 10 Gbps outbound and inbound channels for transmit and receive, respectively, resulting in a high-performance cluster system.

• Journal of the Korea Society for Simulation
• /
• v.20 no.2
• /
• pp.67-76
• /
• 2011

Order picking in automotive service parts warehouses is considered to be the most labor-intensive operation. Such warehouses contain hundreds of thousands of items, but normally 20% of products contribute to about 80% of turnover according to Pareto's 80-20 principle. Therefore most fast moving items are located near an outbound area which is called the "Golden Zone". Order picking routing efficiency is related to productivity and labor cost. However, most companies use simple methods. In this paper, we describe a series of computational experiments over a set of test cases where, we compared various previously existing routing heuristics to an optimal algorithm. We focus on examining the influence of the golden zone on the performance and selection of routing methods. The results obtained show that the optimal routing method increases the productivity at least 17.2%, and all the routing methods have better performance as the pick up rate from the golden zone increases.

• Journal of Navigation and Port Research
• /
• v.41 no.4
• /
• pp.229-234
• /
• 2017

Container terminal yards operate under a high degree of uncertainty as the contact point between inbound and outbound operations of vessels and external trucks. The layout, equipment operations. and job orders at the yards determine the efficacy and delays of the work, so many studies have investigated improvements in efficiency. H company, a container terminal operator developed an index called WDI to distribute work among RTGCs. The WDI is an indicator to prevent congestion in one place by equally distributing the work to each RTGC. This paper analyzes the effect of the WDI introduction and discusses the causes and results of the WDI introduction effect from quantitative and qualitative perspectives.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.2D
• /
• pp.205-216
• /
• 2008

Urban freeway is defined as the roadway with 4 lanes or more which requires a high design criteria for handling a large capacity of vehicles rapidly as a high-speed exclusive roadway in the city. However, most of the urban freeways suffer from severe traffic congestion due to the increased traffic exceeding their capacities regardless of the morning and afternoon rushhours or the inbound and outbound directions. The purpose in this study is to collect and investigate the real-time traffic characteristics based on the ramp junction influence areas of the urban freeway connected with the Busan port, compare and analyze the traffic characteristic relationship for each lane within the ramp junction influence areas, and finally assess and suggest the optimal capacity for each lane within the ramp junction influence areas.

• Journal of the Ergonomics Society of Korea
• /
• v.36 no.5
• /
• pp.579-587
• /
• 2017

Objective: The purpose of this study is to measure the workload of Korea coastal ship crew members, to investigate whether they are following work-break time regulations and to identify the main causes of their workload. Background: According to the US Coast Guard, about 33% of human casualties are reported to be due to fatigue, and 30% of marine casualties reported by the British Marine Accident Investigation Agency (MAIB) are attributed to crew fatigue. But the coastal ship are not managed for business hours and breaks despite the harsh environment. Method: The workload of duty crew members on the 100 domestic coastal vessels was measured. It was also investigated whether they are following domestic and international work-break time regulations. Finally, the marine accidents resulted from the fatigue of the crew was analyzed. Results: As a result of workload analysis, the workload on the 42~62% of the vessels exceeded the standard of working time on the related regulation. The workload increased with the number of inbound and outbound ports. Especially, in the system where there are two seafarers, the workload exceeded the working time requirement. As a result of the marine accidents analysis on 100 vessels, it was found that collision and grounding occurred due to fatigue, workload and drowsiness in 7 marine accidents out of 30 marine accidents. Conclusion: It is necessary for the shipping companies to introduce an operation management manual for the management of the crews' workload and reasonable crew arrangement. It is also required for crew members to easily record work times and for shipping companies to manage the record. It would be possible to prevent many marine accidents by providing adequate rest to the crews and flexibly adjusting their working hours. Application: The results of this study can be used as fundamental data to manage crews' fatigue and to make job management manuals.

• KSCI Review
• /
• v.14 no.2
• /
• pp.235-244
• /
• 2006

This paper attacked the unknown DoS which mixed a DoS attack, Worm and the Trojan horse which used IP Source Address Spoofing and Smurf through the SYN Flooding way that UDP, ICMP, Echo, TCP Syn packet operated. the applications that used TCP/UDP in VoIP service networks. Define necessity of a Dynamic Update Engine for a prevention, and measure Miss traffic at RT statistics of inbound and outbound parts in case of designs of an engine at IPS regarding an Self-learning module and a statistical attack spread. and design a logic engine module. Three engines judge attack grades (Attack Suspicious, Normal), and keep the most suitable filtering engine state through AND or OR algorithms at Footprint Lookup modules. A Real-Time Dynamic Engine and Filter updated protected VoIP service from DoS attacks, and strengthened Ubiquitous Security anger, and were turned out to be.