• Journal of the Microelectronics and Packaging Society
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• v.11 no.3 s.32
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• pp.47-53
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• 2004

Eutectic Au-20Sn(compositions are all in weight percent unless specified otherwise) solder alloys were soldered on the Ni substrate with various time and temperature. The composition, phase identification and morphology of intermetallic compounds(IMC) at the interface were examined using Scanning Electron Microscopy(SEM). There were two types of IMCs, $(Au,Ni)_3Sn_2$ and $(Au,Ni)_3Sn$ at the interface. The transition in morphology of $(Au,Ni)_3Sn_2$ has been observed at $300{\~}400^{\circ}C$. The morphology transition of $(Au,Ni)_3Sn_2$ is due to the decrease of enthalpy of formation of $(Au,Ni)_3Sn_2$ phase and has been explained well by Jackson's parameter with temperature. Because the number of diffusion channel is different at each soldering temperature, IMC thickness is nearly same at all temperature.

• Nuclear Engineering and Technology
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• v.52 no.4
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• pp.661-673
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• 2020

The quarter-core simulation of BEAVRS Cycle 2 depletion benchmark has been conducted using the MCS/CTF coupling system. MCS/CTF is a cycle-wise Picard iteration based inner-coupling code system, which couples sub-channel T/H (thermal/hydraulic) code CTF as a T/H solver in Monte Carlo neutron transport code MCS. This coupling code system has been previously applied in the BEAVRS benchmark Cycle 1 full-core simulation. The Cycle 2 depletion has been performed with T/H feedback based on the spent fuel materials composition pre-generated by the Cycle 1 depletion simulation using refueling capability of MCS code. Meanwhile, the MCS internal one-dimension T/H solver (MCS/TH1D) has been also applied in the simulation as the reference. In this paper, an analysis of the detailed criticality boron concentration and the axially integrated assembly-wise detector signals will be presented and compared with measured data based on the real operating physical conditions. Moreover, the MCS/CTF simulated results for neutronics and T/H parameters will be also compared to MCS/TH1D to figure out their difference, which proves the practical application of MCS into the BEAVRS benchmark two-cycle depletion simulations.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.617-625
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• 1995

Distribution of wholesale carcass cuts and tissues was studied in Omani Dhofari bulls and steers raised under intensive management and slaughtered over a range of 110 to 210 kg body weight. The fore quarter of Dhofari cattle carcasses was heavier than the hind quarter with the chuck being the heaviest cut in the half carcass followed by the round whereas the flank was the lightest cut. Proportions of the fore quarter and its cuts increased whereas that of the hind quarter and its cuts decreased with increasing carcass weight. The fore quarter contained higher proportions of carcass tissues especially intermuscular fat than the hind quarter. The chuck and round contained the highest proportions of lean and bone and the flank the least. There was a general trend of increasing proportions of fat and decreasing proportions of lean and bone in carcass cuts and fore and hind quarters with increasing slaughter weight and age. As % total body fat (TBF), total carcass fat (TCF) increased whereas total non-carcass fat (TNCF) decreased. The largest proportion of TBF was deposited in the intermuscular site. Among the TNCF depots, the kidney and omental contributed the highest proportions whereas the pelvic and channel were the lowest. Proportions of M. rhomboideus and M. splenius increased in the half carcass whereas that of M. semitendinosus decreased as the cattle increased in size. The axial skeleton contributed 47.4-51.1, the fore limb 21.6-22.6 and the hind limb 23.9-26.2% of the total carcass bone. Proportions of axial skeleton increased whereas that of fore and hind limbs decreased with increasing slaughter weight and age. There were no major effects of castration on the distribution of weight of carcass cuts or carcass tissues. Steers had higher total body fat at 160 kg body weight and higher proportions of mesenteric, scrotal, pelvic, kidney and total non-carcass fat at 210 kg weight than bulls. As % of total body fat, steers fad significantly higher kidney and total non-carcass fat. There was little effects of castration on proportions of dimensions of individual muscles or bones.

• Atmosphere
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• v.25 no.4
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• pp.577-589
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• 2015

An unusual long-period and heavy snowfall occurred in the Yeongdong region from 6 to 14 February 2014. This event produced snowfall total of 194.8 cm and the recordbreaking 9-day snowfall duration in the 103-year local record at Gangneung. In this study, satellite-derived cloud-top brightness temperatures from the infrared channel in the atmospheric window ($10{\mu}m{\sim}11{\mu}m$) are examined to find out the characteristics of clouds related with this heavy snowfall event. The analysis results reveal that a majority of precipitation is related with the low-level stratiform clouds whose cloud-top brightness temperatures are distributed from -15 to $-20^{\circ}C$ and their standard deviations over the analysis domain (${\sim}1,000km^2$, 37 satellite pixels) are less than $2^{\circ}C$. It is also found that in the above temperature range precipitation intensity tends to increase with colder temperature. When the temperatures are warmer than $-15^{\circ}C$, there is no precipitation or light precipitation. Furthermore this relation is confirmed from the examination of some other heavy snowfall events and light precipitation events which are related with the low-level stratiform clouds. This precipitation-brightness temperature relation may be explained by the combined effect of ice crystal growth processes: the maximum in dendritic ice-crystal growth occurs at about $-15^{\circ}C$ and the activation of ice nuclei begins below temperatures from approximately -7 to $-16^{\circ}C$, depending on the composition of the ice nuclei.

• 한국해양학회지
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• v.30 no.4
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• pp.250-261
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• 1995

This study was carried out to investigate the distribution of the benthic polychaetous community in Kamak Bay, in summer of 1993. Polychaetes, the dominant faunal group comprising 74.5% of the total number of fauna, consisted of a total of 84 species with a mean density of 112 indiv.m/SUP -2/. The number of species and density were higher in the mouth area of the bay than in the rest of the bay. The most dominant Polychaete was Tharyx sp.(31.9%), followed by Lumbrineris longifolia (27.5%), Chone sp.(4.5%) and Glycera chirori (4.2%). The correspondence analysis revealed that the study area could be divided into four regions. Northeastern channel and southern mouth region of the bay, named Tharyx-Chone assemblage, sustained higher polychaetous density and species number due to the active water exchange with the outer off-sea, whereas northwestern region of the bay had the poorest polychaetous assemblage in the species number and faunal density owing to the blocking water exchange, high organic enrichment in sediment, and low dissolved oxygen content of bottom water. The central region, named Praxillella-Terebellides assemblage and Gly-cera assemblage, was the transition zone between another two region in species composition.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.167-167
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• 2000

전지 재료의 충방전 과정 연구에는 X-선 분말회절(x-ray powder diffraction techniques)과 중성자회절을 많이 사용하였다. 하지만 이러한 분석기술은 long-range order의 구조에 관한 정보를 제공하는데 유용하지만 atomic scale의 구조에 관한 정보를 얻기에는 한계가 있다. Li 전지에서의 전기화학적 반응에서는 cathode 물질에 포함된 전이금속의 산화, 환원 반응에 의한 Li 이온의 intercalation (charge process)과 deintercalation (discharge process) 현상이 일어난다. 이러한 충방전 과정은 알려지지 않은 다양한 형태의 위상 변화를 동반하게 되는데 x-선 이나 중성자를 이용한 powder diffraction techniques 로는 단지 정성적인 결정학적 정보를 얻을 수 있다. 따라서 최근에 원자 단위의 local structure에 관한 정보와 electrochemical state에 관한 정보를 동시에 얻을 수 있는 X-ray Absorption Fine Structure (XAFS) 분석기술을 Li 전지분석에 활용하기 시작하였다. XAFS는 하나의 x-ray 흡수원자에 대해서 주변원자들의 원자구조에 관한 정보와 구성 원소의 electrochemical state에 관한 정보를 얻을 수 있는 분석방법이다. X-ray Induced Electron Emission Spectroscopy (XIEES)는 x-ray에 의해서 방출된 전자를 검출하여 스펙트럼을 얻는 기능을 함축적으로 나타낸 것으로, x-ray를 물질 표면에 조사하여 발생하는 광전자, Auger 전자, 이차전자 등을 전자검출기(Channel Electron Multiplier: CEM)로 검출하는 기능과, 시료를 투과한 x-ray와 시료에서 발생하는 형광 x-ray를 비례계수기로 검출하는 기능을 가지고 있다. 이러한 검출 능력을 바탕으로 EXAFS, XANES, Standing Wave Technique, Elemental Composition Analysis, DXRD, Total Reflection Technique 등을 이용하여 물질을 구성하고 있는 원소의 성분, 미세원자구조, 전자구조에 관한 정보를 얻을 수 있는 새로운 spectrometer이다. 본 연구에서는 자체 개발한 XIEES의 XAFS 기능을 이용하여 여러 가지 방법으로 제조한 LiMn2-xO4와 LiMnO2, MnO2에서 Mn K-absorption edge에 대한 chemical state 변화를 측정하였다. Absorption edge에서 chemical shift를 측정하기 위해서는 방사광 가속기 수준의 에너지 분해능(~0.3eV)이 필요하다. 이번 연구에서는 SiO2(3140) monochromator를 사용하고 여기에 맞는 적절한 parameter를 적용하여 x-ray 에너지 분해능을 포항방사광가속기 수준으로 개선하였다. XIEES에서 얻은 스펙트럼과 포항방사광가속기에서 얻은 스펙트럼을 비교하였다. Chemical shift가 일어나는 경향은 두 실험 결과가 잘 일치하였다.

• Fisheries and Aquatic Sciences
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• v.21 no.4
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• pp.9.1-9.7
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• 2018

To establish a comprehensive management strategy, as part of the optimization of cultural practice for an oyster rack culture system, we used a numerical model to estimate the primary production in the waters on the eastern coast of Wando island, South Korea. The estimated primary production ranged from 17.12 to $1052.55mgC\;m^{-2}day^{-1}$ ($204.22{\pm}224.75mgC\;m^{-2}day^{-1}$ in average). Except for the times of peak phytoplankton blooms, the estimated primary production (PP) was consistently under $200mgC\;m^{-2}day^{-1}$, which is more similar to the value of PP measured off the western coast of South Korea than the southern coast. No clear relationship was observed between nitrogen content and rainfall with the exception of heavy rainfall events, indicating that precipitation might not be the main source of nutrients in these waters. No clear influence was observed from Doam tidal discharge, located 24 km north from these waters due to main tide comes in this area from the channel between Gunwe-myeon in Wando island and Pukpyeong-myeon in Haenam-gun. Because of the shallow water depth and strong tidal current, resuspension of sediments, which causes an input of nitrogen into the system, could be easily caused by even mild wind and the infrequent passing of ships. Microscopic examination of the phytoplankton composition showed additional contribution of benthic species such as Paralia sulcata into the waters, which increase the productivity of oyster farms in the waters. The availability of nitrate and phosphate for primary production was temporarily limited throughout most of the spring and autumn blooming season.

• Journal of Digital Convergence
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• v.18 no.3
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• pp.333-339
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• 2020

The lifestyle of the new consumer class of people with diversified social structures and tastes is affecting society as a whole. As of now, emerging lots of complex cultural space with unique sensibility and individuality, this paper is about proposing the branding of a complex cultural space. I selected Sounds Hannam as a cultural complex and conducted in-depth interviews about brand experience and Ethnography. The study found that Sounds Hannam needs sense of hearing and smell because the sensory factors of the Sounds Hannam are concentrated in the visual field, and also, there is a need to create an appropriate communication channel through SNS. The Sounds Hannam had the characteristic factors of sensibility, relaxation and content based on a diversity different from the existing one. Throughout research, it was derived that planning space as a place to inspire people through spatial composition that triggers behavior and creative thinking is the goal of a complex cultural space and at the same time, an effective way to reflect the lifestyle of those in 20s.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.16.1-16.1
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• 2009

We have fabricated solution processed oxide semiconductor active layer for thin film transistors (TFTs). The oxide semiconductor layers were prepared by ink-jet printing the sol-gel precursor solution based on doped-ZnO. Inorganic ZnO-based thin films have drawn significant attention as an active channel layer for TFTs applications alternative to conventional Si-based materials and organic semiconducting materials, due to their wide energy band gap, optical transparency, high mobility, and better stability. However, in spite of such excellent device performances, the fabrication methods of ZnO related oxide active layer involve high cost vacuum processes such as sputtering and pulsed laser deposition. Herein we introduced the ink-jet printing technology to prepare the active layers of oxide semiconductor. Stable sol-gel precursor solutions were obtained by controlling the composition of precursor as well as solvents and stabilizers, and their influences on electrical performance of the transistors were demonstrated by measuring electrical parameters such as off-current, on-current, mobility, and threshold voltage. Microstructure and thermal behavior of the doped ZnO films were investigated by SEM, XRD, and TG/DTA. Furthermore, we studied the influence of the ink-jet printing conditions such as substrate temperature and surface treatment on the microstructure of the ink-jet printed active layers and electrical performance. The mobility value of the device with optimized condition was about 0.1-1.0 $cm^2/Vs$ and the on/off current ratio was about $10^6$. Our investigations demonstrate the feasibility of the ink-jet printed oxide TFTs toward successful application to cost-effective and mass-producible displays.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.2
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• pp.83-91
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• 2006

Internet shopping mall has become a huge distribution channel with dramatic growth in recent years. The number of consumers has exponentially increased as the scale of shopping mall has been large so that shopping malls with thousands or millions of consumers become a general case. However, it is essential to evaluate whether current assortment of consumers is proper or not in the strategic aspect in order to operate Internet shopping mall effectively and gain profits. That is, it is important to evaluate whether consumer strategy of corporation is proper or not from the corporation. Despite this business importance, consumer assortment has not been evaluated well and related study is not sufficient. This study supposes a framework for consumer assortment evaluation, which evaluates whether consumer assortment of Internet shopping mall is proper or not. In the framework for consumer assortment evaluation, analysis data based on order data and consumer data in database is made. Then, four factors, consumer maintenance rate, consumer profitability, consumer securing rate and consumer conversion are setup, and 22 measurement indexes are drawn. Finally, a consumer assortment evaluation score card is made by integrating them. This study has applied a supposed framework to a domestic typical community based shopping mall, and it is expected that the evaluation result will be used as informant strategic information to operate the shopping mall effectively.