• 수산해양기술연구
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• 제41권4호
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• pp.296-305
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• 2005

Acoustic target strength (TS) of 12 commercially important fish species caught in the Korean waters had been investigated and their results were presented. Laboratory measurements of target strength on 12 dominant fish species were carried out at a frequencies of 75 kHz by single beam method under the controlled condition of the water tank with the 241 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 75 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 fish length and fish species. An empirical model for fish target strength(TS, dB) averaged over the dorsal aspect of 158 fishes of 7 species and which spans the fish length(L, m) to wavelength(${\lambda}$, m) ratio between 6.2 and 21.3 was derived: TS: 27.03 Log(L)-7.7Log(${\kanbda}$)-17.21, ($r^2$=0.59).

• 한국항만경제학회지
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• 제31권3호
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• pp.155-166
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• 2015

본 논문은 효율적인 컨테이너 터미널의 영향력을 평가하기 위해 광양항과 부산항 컨테이너 터미널을 분석대상으로 선정하였다. 연구방법은 DEA분석(CCR, BCC모형) 후 DMU를 노드로 하고, DEA(BCC모형)의 참조집단과 람다값을 이용하여 사회 네트워크를 생성하고 아이겐벡터 중심성 분석에 의해 효율적인 DMU들의 영향력을 분석하였다. 분석결과는 첫째, DEA분석 결과 CCR효율성은 부산항의 PNC, HJNC, HPNT 컨테이너 터미널이 효율성 1이고, BCC효율성은 부산항의 신감만부두, 우암부두, PNC, HJNC, HPNT, BNCT 컨테이너 터미널이 효율성 1이다. 둘째, SNA분석 결과 아이겐벡터 중심성 분석에 의하면 HJNC터미널이 0.515로 가장 많이 참조되고 있는 컨테이너 터미널로 영향력이 가장 높은 것으로 볼 수 있다. PNC터미널이 0.512, 우암부두가 0.379, 순이고 광양항의 CJ대한통운 전체 영향력에서는 4위이나, 광양항 컨테이너 터미널 중에서는 0.256으로 가장 영향력있는 컨테이너 터미널이다.

• Bulletin of the Korean Chemical Society
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• 제30권12호
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• pp.3021-3024
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• 2009

$Zn_2Ti_{1-x}Fe_xO_4\;(0\;{\leq}\;x\;{\leq}\;0.7)$ photocatalysts were synthesized by polymerized complex (PC) method and investigated for its physico-chemical as well as optical properties. $Zn_2Ti_{1-x}Fe_xO_4$ can absorb not only UV light but also visible light region due to doping of Fe in the Ti site of $Zn_2TiO_4$ lattice because of the band transition from Fe 3d to the Fe 3d + Ti3d hybrid orbital. The photocatalytic activity of Fe doped $Zn_2TiO_4$ samples for hydrogen production under UV light irradiation decreased with an increase in Fe concentration in $Zn_2TiO_4$. Consequently, there exists an optimized concentration of iron for improved photocatalytic activity under visible light (${\lambda}{\leq}$420 nm)

• Journal of electromagnetic engineering and science
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• 제18권2호
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• pp.78-87
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• 2018

This paper describes specular reflectance measurements of dielectric plates in three waveguide frequency bands: D-band (110-170 GHz), G-band (140-220 GHz), and J-band (220-325 GHz). The transmit (Tx) part of the proposed specular reflectance measurement system is stationary, while the receive (Rx) part and the material under test (MUT) holder are concentric-rotating with a 2:1 speed ratio for specular reflectance measurements. In specular reflectance measurements, the first step measures the specular reflection coefficients of an MUT and a metal plate on the MUT holder located at the center of the Tx and Rx parts, and the second step calculates the specular reflectance defined by the specular reflection power (i.e., intensity) of the MUT normalized to that of the metal plate. Multiple reflection effects between the Tx and Rx antennas and the MUT on the measured specular reflectance are minimized by averaging out the multiple specular reflectances measured with changing the separation distance between the two antennas by ${\lambda}/8$ intervals. Measurement results of the perpendicular-polarized specular reflectance of commonly used dielectric plates are verified by comparing those with the analytic results and show that the results measured over the overlapped frequency range of the D-/G-bands and at the boundary frequency of the G-/J-bands agree well with the results for the other band, respectively.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권5호
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• pp.658-666
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• 2004

분리가능 시스템은 람다 계산법의 분리가능성을 따라서 정의된 항 개서 시스템이다. 본 연구에서는 기존 구성자 시스템에 한정되어 연구되었던 분리가능 시스템의 정의를 일반 항 개서 시스템으로 확장하고, 이 시스템의 특징을 전진 분지성 및 지수 추이성과 연관하여 설명한다. 분리가능성은 전진 분지성과 동일하며, 지수 추이성을 만족하는 강 순차성은 분리가능성을 갖는다. 이러한 특성에 따라 분리가능 시스템의 패턴 매칭 과정은 지수 트리 형태의 오토마타로 표현될 수 있고, 단순한 패턴을 갖고 있는 구성자 시스템으로 변환될 수 있는 장점을 갖고 있다. 특히, 분리가능 시스템은 람다 계산법으로 번역될 수 있다. ML이나 Haskell과 같은 함수형 언어들은 분리가능 시스템의 한 부류이므로, 본 연구는 함수형 언어의 의미를 람다 계산법으로 설명할 수 있도록 하는 이론적 기반으로도 이용될 수 있다.

• 동의생리병리학회지
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• 제19권2호
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• pp.304-314
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• 2005

The major concept of Sasang typology is that the disease susceptibility and drug response as well as physiological characteristics are presumed to be different depending on their Sasang types. Although characterizing fundamental basis of their traits are crucial in this research field, only pathological susceptibility and physical appearances were thoroughly studied. We evaluated their physiological characteristics by tapping psychological, physical and genetic traits of each Sasang types. After determining the Sasang type of one hundred three college students based on the Questionnaire for the Sasang Constitution Classification, the psychological, physical and genetic traits of each type were analyzed with the Myers-Briggs Type Indicator (MBTI), Bioelectrical Impedance Analysis and genetic polymorphism test, respectively. Each of the Sasang types showed significantly different profiles (Generalized estimation equation, coef=11.88, z=2.13, p=0.033), and could be distinctively classified based on their MBTI scores (discriminant analysis Wilks Lambda=0.611, df=8, chi-square=36.7, p<0.001). Subjects with the So-Eum type (Introversion and Judging) and the So-Yang type (Extroversion and Perceiving) showed contrasting psychological features, however they had similar anthropometric characteristics. Subjects with the Tae-Eum type showed bigger Body Mass Index ($R^2$=0.22, df=4, 74, F=5.07, p=0.001) and body shape compared to others. Although there were no significant differences in G-protein beta-3 subunit polymorphism, angiotensin-converting enzyme polymorphism and Methylenetetrahydrofolate reductase polymprhisms among groups with Sasang types, it was shown that the dopamine system could be one for genetic marker for Sasang typology. These results demonstrated distinctive and essential traits of Sasang typology using reproducible psychometric, anthropometric and genetic evaluations. We also found that the Sasang typology was a bio-psychological typology which could show trait-specific guideline for individualized medicine.

• 한국환경과학회지
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• 제15권1호
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• pp.33-43
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• 2006

Revetment Mattress/Filter is the porous structure filled fillers in meshed structure so that it cail use the fillers of various sizes and form various pores. The porous structure of the Mattress/Filter increases drainage so that it decreases the energy and erosion of flow therefore the tractive force is decreased and the erosion of revetment is mitigated. The filler of Mattress/Filter uses gravels, waste concretes and slags so that the surface is rough and the roughness coefficient increases and the increase of the roughness coefficient decreases flow velocity and tractive force. On the other hand Mattress/Filter and vegetation are combined so that the increase of roughness coefficient and flow velocity still more progress therefore the effect of decrease of tractive force is increased after a few months have passed since the Mattress/Filter is constructed so that the vegetation is developed and be stabilized. The vegetation channel of Mattress/Filter is set tip and the inspection comes into operation by varing flowrate and vegetation spacing to examine these characters of the Mattress/Filter The coefficient of flow velocity U/U*' is decreased exponentially as vegetation esity aH' or $\lambda$ is increased and the coefficient of friction f is increased as vegetation desity aH' is increased but decreased as the coefficient of flow velocity U/U*' is increased. The effective tractive force $F_0$ is decreased exponentially as the vegetation desity aH' is increased. From the inspection the results are obtained that the porous and vegetation structure of the revetment Mattress/Filter system increases the coefficient of friction of revetment so that flow velocity and effective are decreased therefore greatly contributes the stability of the revetment.

• 한국태양에너지학회 논문집
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• 제37권4호
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• pp.35-47
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• 2017

Energy efficiency solutions are being pursued as a sustainable approach to reducing energy consumption and related gas emissions across various sectors of the economy. Vacuum Insulation Panel (VIP) is an energy efficient advanced insulation system that facilitates slim but high-performance insulation, based on a porous core material evacuated and encapsulated in a barrier envelope. Although VIP has been applied in buildings for over a decade, it wasn't until recently that efforts have been initiated to propose and adopt a global standard on characterization and testing of VIP. One of the issues regarding VIP is its durability and aging due to pressure and moisture dependent increase of the initial low thermal conductivity with time; more so in building applications. In this paper, the aging of commercially available VIP was investigated experimentally; thermal conductivity was tested in accordance with ISO 8302 standard (guarded hot box method) and long-term durability was estimated based on a non-linear pressure-humidity dependent equation based on study of IEA/ECBCS Annex 39, with the aim of assessing durability of VIP for use in buildings. The center-of-panel thermal conductivity after 25 years based on initial 90% fractile with a confidence level of 90 % for the thermal conductivity (${\lambda}90/90$) ranged from 0.00726-0.00814 (W/m K) for silica core VIP. Significant differences between manufacturer-provided data and measurements of thermal conductivity and internal pressure were observed.

• 한국재난정보학회 논문집
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• 제18권1호
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• pp.228-240
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• 2022

건설현장의 밀착형 안전관리를 위해 중대재해처벌법이 시행됨에 따라서 종합적 안전관리체계가 요구되고 있다. 안전관리수준평가관리는 건설기술진흥법에 따른 안전관리와 산업안전보건법에 따르는 보건위생 관리 체계와 안전경영시스템 등의 종합적 관계분석이 필요하다. 연구목적: 중대재해처벌법에 따른 안전. 보건관리의 종합적 분석 및 관계를 연구하여 보건위생관리의 안전평가수준향상에 궁극적 목적이 있다. 연구방법: 건설현장 전문가와 안전 관리자 대상으로 2차 델파이분석을 통해 설문항목의 타당성을 확인 후 구조방정식 예비모형을 통해 안전경영, 안전관리, 보건관리, 안전점검실행에 대한 잠재변인이 존재하는 회귀계수확인과 경로분석을 통해 총 효과(직접효과, 간접효과)로 매개효과를 확인하였다. 결과 및 결론: 구조모형에서는 안전관리, 보건체계, 안전경영에서 안전점검실행으로 가는 회귀계수(89%) 와 적정한 관찰변수의 람다 값이 확인되었다. 경로분석에서 보건계획수립적절성과 사후점검관리의 관계에서 보건위생을 매개하여 총 효과(.809)를 확인하였으며, 가설구조물안전성의 경로계수(.82)가 확인되었다.

• 한국재료학회지
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• 제8권6호
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• pp.520-525
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• 1998

활성제로 $Eu^{+2}$을 사용한 BaO-MgO-$AI_2O_3$에서 화학조성 변화에 따른 청색 형광체의 광학특성을 254nm 자외선 및 147nm의 진공자외선 하에서 측정하였다. 동 형광체는 자외선 및 진공자외선 조사를 받아 주 파장이 445nm 인 가시광선의 청색을 발하는 형광체이다. $BaMgAI_{14}O_{23}$ : Eu 농도에 따라 증가하였으며 진공자외선의 경우에는 5%농도에서 최대가 됨을 알 수 있었다. 자외선 및 진공자외선 모두에서 $BaMgAI_{10}O_{17}$형광체의 청색 발광강도는$BaMgAI_{14}O_{23}$보다 좋았다. 또한 $BaMgAI_{10}O_{17}$에서 Ba대신 Ca이나 Sr을 0.1mole 치환시킨 $Ba_{0.9}Ca_{0.1}MgAI_{10}O_{17}$과 $Ba_{0.9}Sr_{0.1}MgAI_{10}O_{17}$ 형광체로 광특성을 더욱 개선할 수 있었다.