• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.4
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• pp.265-275
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• 2005

A prerequisite for deriving the abundance estimates from acoustic surveys for commercially important fish species is the identification of target strength measurements for selected fish species. In relation to these needs, the goal of this study was to construct a data bank for converting the acoustic measurements of target strength to biological estimates of fish length and to simultaneously obtain the target strength-fish length relationship. Laboratory measurements of target strength on 15 commercially important fish species were carried out at five frequencies of 50, 70, 75, 120 and 200 kHz by single and split beam methods under the controlled conditions of the fresh and the sea water tanks with the 389 samples of dead and live fishes. The target strength pattern on individual fish of each species was measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down aspect) to $+45^{\circ}$ (head up aspect) in $0.2^{\circ}$ intervals, and the averaged target strength was estimated by assuming the tilt angle distribution as N $(-5.0^{\circ},\;15.0^{\circ})$. The TS to fish length relationship for each species was independently derived by a least-squares fitting procedure. Also, a linear regression analysis for all species was performed to reduce the data to a set of empirical equations showing the variation of target strength to a fish length, wavelength and fish species. For four of the frequencies (50, 75, 120 and 200 kHz), an empirical model for fish target strength (TS, dB) averaged over the dorsal sapect of 602 fishes of 10 species and which spans the fish length (L, m) to wavelength (\Lambda,\;m)$ ratio between 5 and 73 was derived: $TS=19.44\;Log(L)+0.56\;Log(\Lambda)-30.9,\;(r^2=0.53)$.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.15-20
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• 2012

The authenticity of bank note is threatened by increasing a counterfeit note with development of the information industry, recently. The importance of counterfeit discrimination is stressed, but there is a limits to popularization. Because usually, the existing counterfeit discriminator uses invisible ray zone like UV, IR, etc. The purpose of this paper is the construction of counterfeit discrimination system for \50,000 won bills. This system is used optical fiber sensor with excellent confidence as well as easy way of using in wave length of a visible ray zone. The light was altered by lightening optical fiber sensor to particular part of bank notes in order displacing response of optical fiber sensor. The experiment was processed with data of 100 bank notes on manufacture optical fiber, probe, jig. As a result, the discrimination conuterfeit was verified when the experiment was processing with hologram or CSI on the bank notes with three kinds of color printer.

• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.28-38
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• 2014

Construction value engineering(VE) is often performed in the form of a short term review of designs, rather than during a regular workshop with a standardized work plan, and its application method is limited. Thus, tasks are performed by applying the method in reverse depending on the VE results, and function analysis, a key VE method, is omitted or only applied for the sake of formality. In addition, it is hard to expect great results from VE because of insufficient time and budget allowed to perform VE and a lack of understanding of VE procedures and methods. In particular, the methods used to store and reuse the tremendous amount of ideas and information created during the process of VE implementation is not systematic. Even the Korea Expressway Corporation, which has produced relatively systematic VE performance compared to other institutions, has had the above-mentioned problems. Therefore, this study aims to improve existing VE processes and suggest a method to efficiently store and retrieve VE information by analyzing the limitations of construction VE practice and the characteristics of VE for highway facilities as part of improving design VE performance.

• Korean Journal of Construction Engineering and Management
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• v.20 no.6
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• pp.107-116
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• 2019

Korean construction engineering firms want to pave the way for expansion of overseas markets through the World Bank's Official Development Assistance (ODA) projects as a way to improve their overseas project performance. However, since the World Bank project competes with global companies for limited projects, building partnerships with suitable business partners is essential to gain an upper hand in bidding competition and meet the institutional conditions of the recipient country. In this regard, many network studies have been conducted in the past through Social Network Analysis (SNA), but few have been analyzed based on the process of changes in the network. So, This study collected winning data from the three Southeast Asian countries that ended after the World Bank's ODA project performed smoothly, and established a learning-based link prediction model that reflected the dynamic nature of the network. As a result, the 11 main variables acting on building a cooperative relationship between winning companies were derived and the effect of each variables on the probability value of cooperation between individual links was identified.

• Journal of Korea Water Resources Association
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• v.39 no.2 s.163
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• pp.179-186
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• 2006

We analyzed the harmonic and non-harmonic constant of Geum River estuary to know tidal change of the before and after construction at Geum River estuary dike. As a result of analysis, the harmonic and non-harmonic constant after estuary dike building increased. Also, depth change analyzed at each section by using each year chart data. As a result, scour was occurred in the channel between south and north side guide bank. And accretion was occurred at channel from Kunsan outer port to estuary dike. Tidal change was judged as the effect of construction and dredge, watergate closing at Geum River estuary dike. And water depth change is a cause by effection of Geum River estuary dike construction and, south-north side guide bank, Kunjang country industrial complex furtherance business, seamangeum 4th sea bankment construction.

• Korean Journal of Oriental Medicine
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• v.10 no.2
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• pp.51-62
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• 2004

Through the survey of related studies for last ten years, it was known that accurate sample data of sasang constitution are the most important condition in sceintific research of sasang constitutional medicine. So we can propose three step for scientific sasang constitution medicine: firstly, the construction of SCIM(Sasang Constitutional Information Bank); secondly, the development of instruments for constitution diagnosis; thirdly, the new diagnosis methods based on the organic definition of sasang constitution.

• Korean Journal of Construction Engineering and Management
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• v.19 no.1
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• pp.80-89
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• 2018

World Bank projects enable Korean engineering firms to enter new markets and diversify their portfolio. These firms need to understand the critical factors for bidding success in such projects. The World Bank publishes as open records all their bidding history data in their open database. This provides an opportunity to identify empirically the factors that determine which firms on chosen. This research collected relevant bid data, focusing on Indonesia, to perform a logistic regression with the goal of statistically identifying significant factors that result in bidding success. Results showed that work experience, being included in a consortium, and having a local partner positively affected winning a bid. On the other hand, having a local competitor of the recipient country negatively impacts the chances of attaining a bid. Commensurately, Korean engineering firms need to increase their work experience in internationally recognized projects, and include a local partner as a joint venture partner to increase their chances, while refrain from conventional projects that can be performed by local engineering firms.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.21-29
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• 2015

Construction cost index (CCI) has been published for last 10 years, it's contributed to update the historical cost data, analysis cost fluctuation and evaluate the market price for construction works with direct or indirect manner. CCI is a secondary or processed statistics using the basic statistics of input output table (IO table) and producer price index (PPI) from the Bank of Korea (BOK). So once the basic statistics change, it is required to modify the calculating model of CCI. Recently the BOK changed some fundamental principles and the base year (from 2005 to 2010), that can be used in IO table and PPI. This research analyzed the recent revision of basic statistics and their impacts on CCI, and improved the previous CCI model in response to it. Also the validity of new CCI was verified by analyzing the items and weights utilized in CCI and comparing the related index.

• Korean Journal of Construction Engineering and Management
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• v.7 no.2 s.30
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• pp.53-61
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• 2006

Korean Government started to publish Korean CCI(Construction Cost Index) again at February 2004 since CAK(Construction Association of Korea) stopped publishing it 1994. CCI is developed using the verified statistical data, that is, input-output table and producer price index by Korean Bank and labor unit cost by CAK. Though the method is available as it uses the verified statistical data, there is a limitation to reflect the characteristics of construction. For overcoming this limitation, this study suggests CCI development method investigating the input structure of labor and material cost for each type of construction project and applying the cost variations of the items.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.259-264
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• 2009

Most of the fossil power plants firing lower grade coals are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases significant derate, availability losses and increase in unburned carbon levels can be attributed to poor combustion conditions as a result of poorly controlled local fuel and air distribution within the boiler furnace. The poor combustion conditions are directly related to the gas flow deviation in upper furnace and convection tube-bank but a less reported issue related to in large-scale oppose wall fired boilers. In order to develop a on-line combustion monitoring system and suggest an alternative heat flux estimation method at tube bank, which is very useful information for boiler design tool and blower optimizing system, field test was conducted at operating power boiler. During the field test the exhaust gases' temperature and tube metal temperature were monitored by using a spatially distributed sensors grid which located in the boiler's high temperature vestibule region. At these locations. the flue gas flow is still significantly stratified, and air in-leakage is minimal which enables tracing of poor combustion zones to specific burners and over-fire air ports. Test results showed that the flue gas monitoring method is more proper than metal temperature distribution monitoring for real time combustion monitoring because tube metal temp. distribution monitoring method is related to so many variables such as flue gas, internal flow unbalance, spray etc., Heat flux estimation at the tube bank with flue gas temp. and metal temp. data can be alternative method when tube drilling type sensor can't able to use.