• The Journal of the Acoustical Society of Korea
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• v.39 no.6
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• pp.606-614
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• 2020

In this paper, we analyze the influences of ship traffic and marine weather information on underwater ambient noise. Ambient noise is an important environmental factor that greatly affects the detection performance of underwater sonar systems. In order to implement an automated system such as prediction of detection performance using artificial intelligence technology, which has been recently studied, it is necessary to obtain and analyze major data related to these. The main sources of ambient noise have various causes. In the case of sonar systems operating in offshore seas, the detection performance is greatly affected by the noise caused by ship traffic and marine weather. Therefore, in this paper, the impact of each data was analyzed using the measurement results of ambient noise obtained in coastal area of the East Sea of Korea, and public data of nearby ship traffic and ocean weather information. As a result, it was observed that the underwater ambient noise was highly correlated with the change of the ship's traffic volume, and that marine environment factors such as wind speed, wave height, and rainfall had an effect on a specific frequency band.

• Journal of the Korean Chemical Society
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• v.24 no.5
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• pp.380-392
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• 1980

Six coordinate low spin iron(Ⅱ) complexes of vicinal-dioximes, [Fe$(DH)_2B_2$] and [Fe$(DH)_2$B(CO)]($(DH)_2$=$(CHDH)_2$(bis(1,2-cyclohexadinedioximato) bivalent anion), $(DPGH)_2$-(bis(diphenylglyoximato) bivalent anion), $(F{\alpha}DH)_2(bis(furil-{\alpha}-dioximato)$ bivalent anion); B = monodentate neutral nitrogen base), have been prepared and their physical properties have been investigated with respect to the effects of the equatorial ligands, $(DH)_2$. The order of ${\pi}$-acceptor CO stretching frequency for [Fe$(DH)_2$B(CO)] is $(F{\alpha}DH)_2$ > $(DPGH)_2$> $(CHDH)_2$, while non-${\pi}$-acceptor $NH_3$ stretching frequencies for [Fe$(DH)_2(NH_3)_2$] show the opposite order to that of CO, i.e., $(CHDH)_2$ > $(DPGH)_2$ > $(F{\alpha}DH)_2$. These infrared spectral data together with Fe-N (oxime) and Fe-N (oxime) and Fe-N (B) stretching frequency data suggest that the nitrogen atoms of $(CHDH)_2$ are more basic and poorer ${\pi}$-acceptors than the corresponding nitrogen atoms of $(DPGH)_2$ and $(F{\alpha}DH)_2$, respectively. It has been found from the electronic spectral data of [Fe$(DH)_2$] and [Fe$(DH)_2$B(CO)] that the energy of the charge transfer band from iron(Ⅱ) to $(DH)_2$ increases as the basicity of $(DH)_2$ increases.

• Journal of The Korean Astronomical Society
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• v.50 no.3
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• pp.79-92
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• 2017

We present a BV I optical photometric study of the old open cluster Ruprecht 6 using the data obtained with the SMARTS 1.0 m telescope at the CTIO, Chile. Its color-magnitude diagrams show the clear existence of the main-sequence stars, whose turn-off point is located around $V{\approx}18.45mag$ and $B-V{\approx}0.85mag$. Three red clump (RC) stars are identified at V = 16.00 mag, I = 14.41 mag and B - V = 1.35 mag. From the mean $K_s-band$ magnitude of RC stars ($K_s=12.39{\pm}0.21mag$) in Ruprecht 6 from 2MASS photometry and the known absolute magnitudes of the RC stars ($M_{K_S}=-1.595{\pm}0.025mag$), we obtain the distance modulus to Ruprecht 6 of $(m-M)_0=13.84{\pm}0.21mag$ ($d=5.86{\pm}0.60kpc$). From the ($J-K_s$) and (B - V ) colors of the RC stars, comparison of the (B - V ) and (V - I) colors of the bright stars in Ruprecht 6 with those of the intrinsic colors of dwarf and giant stars, and the PARSEC isochrone fittings, we derive the reddening values of E(B - V ) = 0.42 mag and E(V - I) = 0.60 mag. Using the PARSEC isochrone fittings onto the color-magnitude diagrams, we estimate the age and metallicity to be: $log(t)=9.50{\pm}0.10(t=3.16{\pm}0.82Gyr)$ and $[Fe/H]=-0.42{\pm}0.04dex$. We present the Galactocentric radial metallicity gradient analysis for old (age > 1 Gyr) open clusters of the Dias et al. catalog, which likely follow a single relation of $[Fe/H]=(-0.034{\pm}0.007)R_{GC}+(0.190{\pm}0.080)$ (rms = 0.201) for the whole radial range or a dual relation of $[Fe/H]=(-0.077{\pm}0.017)R_{GC}+(0.609{\pm}0.161)$ (rms = 0.152) and constant ([Fe/H] ~ -0.3 dex) value, inside and outside of RGC ~ 12 kpc, respectively. The metallicity and Galactocentric radius ($13.28{\pm}0.54kpc$) of Ruprecht 6 obtained in this study seem to be consistent with both of the relations.

• Journal of IKEEE
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• v.22 no.1
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• pp.180-184
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• 2018

Gallium oxide ($Ga_2O_3$) and silicon carbide (SiC) are the material with the wide band gap ($Ga_2O_3-4.8{\sim}4.9eV$, SiC-3.3 eV). These electronic properties allow high blocking voltage. In this work, we investigated the characteristic of $Ga_2O_3$ and 4H-SiC vertical depletion-mode metal-oxide-semiconductor field-effect transistors. We demonstrated that the blocking voltage and on-resistance of vertical DMOSFET is dependent with structure. The structure of $Ga_2O_3$ and 4H-SiC vertical DMOSFET was designed by using a 2-dimensional device simulation (ATLAS, Silvaco Inc.). As a result, 4H-SiC and $Ga_2O_3$ vertical DMOSFET have similar blocking voltage ($Ga_2O_3-1380V$, SiC-1420 V) and then when gate voltage is low, $Ga_2O_3-DMOSFET$ has lower on-resistance than 4H-SiC-DMOSFET, however, when gate voltage is high, 4H-SiC-DMOSFET has lower on-resistance than $Ga_2O_3-DMOSFET$. Therefore, we concluded that the material of power device should be considered by the gate voltage.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.158-158
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• 2017

비닐포장 하부에 위치한 콩의 생장 초기에 발생한 초엽을 인식하기 위한 연구를 수행중이다. 선행 연구에서 비닐포장에 접촉한 콩 초엽으로 인해 비닐포장 상부 표면의 열 반응 분포에 변화가 있음을 발견하였다. 현장에서 주행 중에 콩 초엽의 위치를 실시간으로 인식하고 연동된 선형 또는 회전형 엑츄에이터를 제어하여 정확한 위치에 천공을 수행하기 위해서는 계측 시스템과 제어 시스템간의 시간적 차이를 최소할 수 있는 실시간 신호 처리 기술이 필수적이다. 선행 연구에서 사용한 다중 IR 센서의 분해능은 $16{\times}4pixel$이며 주파수는 3 Hz로, 폭이 30cm 내외인 비닐포장 상부의 정밀 분석에 한계가 있음을 발견하였다. 이를 해결하기 위하여 분해능과 계측 주기를 개선할 수 있는 초소형 ($1cm{\times}1cm{\times}1cm$) 열화상 센서를 이용하였다. LWIR(Longwave infrared)영역에 해당하는 $8{\mu}m{\sim}14{\mu}m$의 영역에서 $0.05^{\circ}C$의 분해능을 보이는 $ Lepton^{TM}$ (500-0690-00, FLIR, Goleta, CA)모델을 사용하였다. 프레임당 $80{\times}60$ 픽셀의 정보가 2 Byte의 단위로 계측이 되며 9 Hz의 주파수로 대상면의 열 분포를 측정할 수 있다. 이론적으로 초당 정보 전송량은 86,400 Byte ($80{\times}60{\times}2{\times}9$)이며, 1 m를 진행하는 주행형 천공기에 적용할 경우 1 프레임당 10cm 정도의 면적을 측정하므로, 최대 위치 판정 분해능은 약 10 cm / 60 pixel = 0.17 cm/pixel로 상대적으로 정밀한 위치 판별이 가능하다. $80{\times}60{\times}2Byet$의 정보를 0.1초 이내에 분석해야 하는 기술적 과제를 해결하기 위하여 천공 작업기에 적합한 상용 SBC(Single board computer)의 클럭 속도(1 Ghz)로 처리 가능한 공간 분포 분석 알고리즘을 개발하였다. 전체 이미지 도메인을 한 번에 분석하는데 소요되는 시간을 최소화하기 위하여 공간정보 행렬을 균등히 배분하고 별도의 프로세서에서 Feature를 분석한 후 개별 프로세서의 결과를 경합식으로 판정하는 기술을 연구하였다. 오픈 소스인 MPICH(www.mpich.org) 라이브러리를 이용하여 개발한 신호 분석 프로그램을 클러스터링으로 연동된 개별 코어에 설치/수행 하였다. 2D 행렬인 열분포 정보를 공간적으로 균등 분배하여 개별 코어에서 행렬의 Spatial domain analysis를 수행하였다. $20{\times}20$의 클러스터링 단위를 이용할 경우 총 12개의 코어가 필요하였으며, 초당 10회의 연산이 가능함을 확인하였다. 병렬 클러스터링 기술을 이용하여 1m/s 내외의 주행 속도에 대응이 가능한 비닐포장 상부 열 분포 분석 시스템을 구현하였다.

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.864-880
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• 2003

A unified picture for magnetism, superconductivity, quantum optics and other properties of molecule-based materials has been presented on the basis of effective model Hamiltonians, where necessary parameter values have been determined by the first principle calculations of cluster models and/or band models. These properties of the matetials are qualitatively discussed on the basis of the spin and pseudo-spin Hamiltonian models, where several quantum operators are expressed by spin variables under the two level approximation. As an example, ab initio broken-symmetry DFT calculations are performed for cyclic magnetic ring constructed of 34 hydrogen atoms in order to obtain effective exchange integrals in the spin Hamiltonian model. The natural orbital analysis of the DFT solution was performed to obtain symmetry-adapted molecular orbitals and their occupation numbers. Several chemical indices such as information entropy and unpaired electron density were calculated on the basis of the occupation numbers to elucidate the spin and pair correlations, and bonding characteristic (kinetic correlation) of this mesoscopic magnetic ring. Both classical and quantum effects for spin alignments and singlet spin-pair formations are discussed on the basis of the true spin Hamiltonian model in detail. Quantum effects are also discussed in the case of superconductivity, atom optics and quantum optics based on the pseudo spin Hamiltonian models. The coherent and squeezed states of spins, atoms and quantum field are discussed to obtain a unified picture for correlation, coherence and decoherence in future materials. Implications of theoretical results are examined in relation to recent experiments on molecule-based materials and molecular design of future molecular soft materials in the intersection area between molecular and biomolecular materials.

• The Korean Journal of Pharmacology
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• v.16 no.2 s.27
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• pp.15-24
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• 1980

[${\alpha}$]-Amylase catalyses the hydrolysis of starch, glycogen, and related poly- and oligosac-charide by random cleavage of ${\alpha}$-D-(l-4) glucan linkage. In man large amounts of amylase are secreted into the digestive tract by the salivary and exocrine pancreatic gland, minimal amount being produced also in other tissues. It has been known that ${\alpha}$-amylase exists in multiple molecular forms, isoenzyme which can be separated from each other because of difference in their physicochemical properties. By using various methods, several groups of investigator have separated the many isoenzyme in serum, saliva and pancreatic juice. Furthermore, changes of the normal serum isoenzyme pattern is diagnostically useful even when the total serum enzyme activity is noninformative, such as the clinical use of isoenzyme of serum lactate dehydrogenase. Procarboxypeptidase-A which is one of the pancreatic enzymes is also present as isoenzymes. Four forms of procarboxypeptidase-A haye been found in the bovine enzyme and three forms of the porcine enzyme. In human pancreatic juice four forms of procarboxypeptidase-A isoenzyme were found by isoelectric focusing method. Recently, the so-called isoamylase analysis was developed for the diagnostic use of amylase in pancreatic diseases. In alcohotic patients, the serum concentration of pancreatic isoamylase is subnormal and this lowered activity provides strong evidence for pancreatic exocrine insufficiency. The purpose of this study was to elucidate the variations of the isoenzyme of amylase and procarboxypeptidase-A in serum, saliva and pancreatic juice of the experimental animals. The results are as follow. 1) Three main forms of isoenzyme of amylase by isoelectric focusing were found in pancreatic juice of normal rabbit. However, many new bands were appeared in the pancreatic juice of cholic acid administered animal intravenously while the infusion of cholic acid or elastase into pancreatic duct produced the decrease of number of the fractions on the isoelectric focusing. In the case of serum isoenzyme from normal animal, two major and a few minor isoamylases were observed. By injecting alcohol intravenousely the fractions of serum isoamylase were significantly decreased and in contrary to the pattern in the pancreatic juice the infusion of cholic acid or elastase into pancreatic duct exhitited a significant decrease of the isoenzyme of amylase fractions. In saliva from normal animal three main isoamylase were produced of the administration of alcohol. 2) In the case of procarboxypeptidase-A isoenzyme, two major fractions which have isoelectric point at 6.2 and 6.4 and other two minor bands were observed in the pancreatic juice of normal rabbit. By the treatment of the juice with trypsin, only one band was produced on the isoelectric focusing. No procarboxypeptidase was appeared on the electrofocusing by the infusion of cholic acid or phospholipase A into the pancreatic duct of rabbit. However, a single major fraction of procarboxypeptidase-A was appeared at 3 hr after simple ligation of the pancreatic duct. No significant changes were observed in the juice of the alcohol or cholic acid administered group.

• Geophysics and Geophysical Exploration
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• v.13 no.3
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• pp.249-255
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• 2010

Since the 1990's, a number of ULF geomagnetic disturbance associated with earthquake occurrences have actively been reported, and polarization analysis of geomagnetic fields becomes one of potential candidates to be capable of predicting short-term earthquake. This study develops the modified polarization analysis method based on the previous studies, and analyzes three-component geomagnetic fields obtained at Cheongyang geomagnetic observatory using the developed method. A daily polarization value (the ratio of spectral power of horizontal and vertical geomagnetic field) is calculated with a focus on the 0.01 Hz band, which is known to be the most sensitive to seismogenic ULF radiation. We analyze a total of 10 months of geomagnetic data obtained at Cheongyang observatory, and compare the polarization values with the Kp index and the earthquake occurred in the analysis period. The results show that there is little correlation between the temporal variations of polarization values and Kp index, but remarkable increases in polarization values are identified which are associated with two earthquakes. Comparison the polarization values obtained at Cheongyang and Kanoya observatory indicates that the increases of polarization values at Cheongyang might be due to not global geomagnetic induction but the locally occurred earthquakes. Furthermore, these features are clearly shown in normalized polarization values, which take account in the statistical characteristics of each geomagnetic field. On the basis of these results, polarization analysis can be used as promising tool for monitoring the earthquake-precursory phenomenon.

• Journal of the Korean Society of Costume
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• v.52 no.8
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• pp.29-39
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• 2002

It was increased leisure hours by automation and computerization of industry. Many people spend on hours in enjoying leisure sports, and then. nowadays, Many women tend to prefer casual wear to formal suits. The purpose of this research was to design of outdoor-wear that improve the functional and aesthetic effects for clothing comfort. Total 4 design prototype consisting of jumper and slacks were developed for this research. Outdoor-wear design forced on armhole type of jumper and ease of the back crotch length of slacks to improve the functional and aesthetic effects. And Outdoor-wear design focused on color harmony to aesthetic effects. Ease amount and materials of jumper and slacks were controlled. Design A: Jumper was designed as dropped shoulder with set-in steeve and band collar, A break-away zipper to facilitate ventilation control were made the area of back of jumper and the area of outside seam line of slacks Color of jumper and slacks were olive green color. Ease amount of the crotch length of slacks pattern was constructed as 7% of total crotch length: Design B 4DM cut pattern were applied to the jumper and slacks pattern. A break-away zipper to facilitate ventilation control were made the area of back of jumper and the area of inside seam line of thigh. Color of jumper and slacks were grey and orange color. Ease amount of the crotch length of slacks pattern was constructed as 5% of total crotch length. Design C : Jumper was designed as the set in sleeve and hood. and A break- away zipper to facilitate ventilation control were made the ares of the armhole and elbow. Color of jumper and slacks were ivory and orange color. Ease amount of the crotch length of slacks pattern was constructed as 5% of total crotch length. Design D : Jumper was designed as raglan sleeve. Color of jumper and slacks were olive green color. Ease amount of the crotch length of slacks pattern was constructed as 5% of total crotch length. Total six females, ages 20-45, served as subjects for this research. Subjects have standard body type, generally, wearing 66 size of ready-to-wear clothing. The performance of the newly designed outdoor-wear was evaluated for their effectiveness in several aspects such as conditions of skin temperature, sensory evaluation of comfort during body movements, appearance and color harmony and aesthetic collar design. Design 3 was appeared to be the most positive in aesthetic evaluation and functional effects of design 2 of 4DM cut pattern was appeared to be beter than other designs.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.22 no.4
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• pp.75-82
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• 1986

A field experiment was carried out to clarify the effect of underwater sound on the luring of fish school. The effects of. the acoustic emission on the luring of fish school were checked actually at a set net fishing site in Namhae using a commercial acoustic equipment, Dairyo-8. An emitting system of sound was designed by the authors, and the ambient noise, the sound pressure level and the reaction of fish school were measured in the set net. 1. The predominent frequency band of ambient noise was 150Hz-400Hz,.and the sound emitted was 400Hz-100Hz. The sound pressure level of ambient noise in set net was higher at the landing part, and lower at the playgrond, the gate of court and "the enterance of inclined "passage. The ambient noise was increased with the time elapse-d at the stage of hauling net, but :it was decreased suddenly at the final stage due probably to the decrease of the swimming speed of the fish school. 2. The results of the observation and the recording paper of echo sounder indicate that the effect of emitting sound in the bag net of set net was remarkable for the luring of fish school in the early stage, but decreased after 30 minutes. The reaction of fish school is more sensitiv2 to the sound pressure level than the time intervals between the emission and the pause. For the purpos~ of practical use, it is nesessary to confirm what kind of sound pressure level is the best for the luring of fish school. 3. In response to the acoustic equipment(Dairyo-8), fish school started to swarm 20 minutes after the sound emission and scattered when the sound paused. As the emitting pattern of the acoustic equiment, the three seconds of emission after one second of pause was more effective than the continuous emission at the set net fishing ground. Catch of the fish(s during th~ sound ernissio:l at the gate of court was three to five times more than that of no emission.