• Textile Coloration and Finishing
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• v.14 no.5
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• pp.277-283
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• 2002

Poly(ethylene terephthalate)(PET) filaments of regular(monodenier 2.08d) and ultramicrofiber (monodenier 0.05d) were treated with dimethylformamide(DMF) to observe the structure change of the PET such as shrinkage, density, X-ray diffraction of the UMF treated with DMF were measured. Also, dyeing experiments were performed to see the effects of DMF. The dyeability was improved by DMF treatments, and the equilibrium dye uptake increased in spite of the increase in the density and birefringence and crystallinity. The heat shrinkage appeared in PET UMF treated PET UMF treated with DMF at $80^\circ{C}$ by TMA, DSC, and Reovibron analysis and $T_m$ peak was shown by DSC analysis.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.271-271
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• 2010

고효율 실리콘 태양전지를 제작하기 위하여 surface passivation, 레이저와 lithography기술들이 연구되어 지고 있다. 결정질 실리콘 태양전지의 기판의 두께가 점점 얇아지면서 surface-to-volume 비율이 증가되어 surface passivation은 매우 중요하다. surface passivation은 크게 2가지 방법으로 진행되고 있으다. 첫 번째는 Si의 dangling bond의 passivation과 surface recombination process 제어에 기초를 두고 있다. 일반적으로 박막을 이용한 실리콘 passivation은 $SiO_2$, SiN, a-Si, $Al_2O_3$박막 4가지가 이용되어 왔다. 본 연구에서는 p-type SoG기판위에 원자층 증착법(ALD)을 이용하여 $Al_2O_3$박막의 negative fixed charge의 internal electric field로 surface passivation을 연구하였다. TMA와 $H_2O/O_3$을 사용하여 ALD $Al_2O_3$를 10~30nm두께를 갖도록 증착하였다. 표면 처리 조건, $Al_2O_3$박막 두께, ALD 공정 조건과 후열처리등에 따른 실리콘의 특성, carrier lifetime변화를 측정하여 효과적인 field induced passivation을 제시하고자 한다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.837-842
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• 2000

Commercially distributed salted and fermented anchovy sauces in Korea were purchased from six different companies. Microbiological, chemical, rheological and sensory analyses were carried out to evaluate the quality and safety and to provide basic information of the products. The salinity of every product was lower than of regulatory standard. All samples tested had acceptable in moisture content and pH. However, wide range of amino nitrogen (AN), volatile basic nitrogen(AN), volatile basic nitrogen (VBN), and trimethylamine (TMA) contents were observed. One product among tested had lower level of AN than regulatory standard. Pathogenic microorganisms were also detected from the samples, therefore sanitation procedure will be needed to ensure safety. From the results, AN, VBN, and viscosity were highly correlated to sensory scores, suggesting that these values can utilized as a standard method to evaluate quality of the salted and fermented anchovy sauce.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.163-163
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• 2016

선박의 대형화 등으로 인한 세계적인 항만들이 하역능력의 제고를 위하여 선박의 대형화, 고속화, 전용선화에 있어 큰 움직임을 보이고 있다. 또한 항만의 연간 작업가능일수 확보를 위하여 신항만 건설시 항 내 정온도 향상을 위하여 최적의 방파제 배치 및 최선의 소파기술에 대한 연구지원을 아끼지 않고 있다. 이뿐 아니라 최근 파랑 수치모형의 정확성이 향상되고 계산시간이 단축됨으로써 각 격자 상에 입력된 수심정보와 입사경계에서의 입사정보 경계면에서의 경계(반사율) 정보로부터 손쉽게 천해파랑 정보를 산출할 수 있게 되었다. 본 연구에서는 스펙트럼을 통해 각각의 파고와 주기를 추출하였으며, 쌍곡선형 완경사 방정식을 수치 해석하여 불규칙파의 설계파를 산정하였다. 또한 Matlab을 사용하여 전 프로그램이 toolbox화 됨으로써 운영하는데 편리하고 특히 다양한 지형의 적용에 용이하게 되었다. Matlab은 다른 언어와 달리 전 프로그램이 vectorizing 되어 계산시간이 상당히 단축되었다. 본 연구를 통해 실무자들이 항만이나 어항 등 연안해역 개발시 유의파고를 사전에 예측하여 연안해역 개발하는 데 큰 도움이 되리라 기대한다.

• Korean Journal of Optics and Photonics
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• v.12 no.5
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• pp.352-355
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• 2001

A null lens is designed for testing the hyperbolic mirror which is the first mirror of the off-axis three mirror anastigmat(TMA) designed as a high resolution camera for remote sensing. To choose a better null lens system for the hyperbolic surface under test, both autostigmatic and mixed type null lenses are designed and analysed for sensitivity with respect to change of each surface parameter such as the radius of curvature and the thickness.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1112-1115
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• 2009

네트워크 관리자 입장에서 효율적인 네트워크 관리를 위해 응용 프로그램 별 트래픽 분류의 중요성이 커지고 있다. 응용 프로그램 별 트래픽 분류를 위해 signature 기반, machine learning 방법들이 제안되고 있지만 p2p 방식의 Skype 응용프로그램에 대한 적용결과는 그 신뢰성이 떨어지고 있는 것은 사실이다. 본 논문에서는 Skype의 트래픽을 분류하기 위해 각 Client 마다 Skype application install 시 동적으로 변화하는 Port 를 알아내는 방법, UDP 패킷의 특정위치의 특정 signature, TCP signal flow의 특정위치 패킷에 대한 payload 크기 등을 이용한 Skype traffic 분류 방법을 제안한다. 제안된 방법론은 학내 네트워크에 적용하여 그 타당성을 TMA를 통해 검증하였다.

• Korea Trade Review
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• v.46 no.2
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• pp.93-106
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• 2021

This study analyzes trade communication methods by comparing and analyzing payment methods and procedures of L/C and BPO transactions. As a result of the study, BPO transaction is validated based on the combination results of the confirmed baseline and data set unlike the L/C transaction. Therefore, BPO is superior to L/C transaction in that there is no confrontation between the parties over the matching results. And it can proceed with certain transaction that is paid first and proved later. In addition, the process of accepting data mismatches results in a confirmation of the payment commitment considering the intention of the importer. This allows flexible disposition of documents in response to the post payment situation as long as the documents are held by the exporter, which can be said to be superior to the L/C transaction.

• Journal of Fisheries and Marine Sciences Education
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• v.3 no.2
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• pp.47-72
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• 1991

To obtain the principal data for useful treatment and processing of Korean geoduck (Panope japonica A. ADAMS) which inhabit mostly at Dong-Hae coastal area in Korea, changes of $NH_2$-N, TMAO, TMA, total creatinine, protein composition and fatty acid composition in raw and blanched geoduck muscle during storage at $-20^{\circ}C$ were investigated. In addition, its chemical composition variation in the whole year was elucidated. The moisture content in geoduck muscle meat was 78.1% to 82% in the whole year. Particularly, in July its moisture content was maximum as 82% and in September minimum as 78.1%. Crude protein was in the range of 12.3-16.4%, crude lipid the average was 1.5%, crude ash on the average was 1.4%. The abundant fatty acids in geoduck muscle oil were $C_{16}$ : 0, $C_{16}$ : 1, $C_{18}$ : 0, $C_{18}$ : 1, $C_{20}$ : 5, and $C_{22}$ : 6 acids. During storage at $-20^{\circ}C$, content of unsaturated fatty acid such as eicosapentaenoic acid (EPA, $C_{20}$ : 5) and docosahexaenoic acid (DHA, $C_{22}$ : 6)in raw geoduck muscle decreased somewhat and the raw geoduck was slightly oxidized. Trimethylamine (TMA), volatile basic nitrogen (VBN)and $NH_2$-N of raw muscle increased compared to blanched muscle. Trimethylamine oxide (TMAO) was slightly decreased during the storage period. The muscle protein was approximately composed of 37% sarcoplasmic, 29% myofibrillar, 22% alkali soluble, and 12% stroma protein. Among several proteins, myofibrillar protein content decreased mostly, while the alkali-soluble and stroma protein content increased slightly during storage at $-20^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.10 no.1
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• pp.1-16
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• 1981

Fermented trepang entrails, Stichopus Japonicus, is widely used and occupied an important position in foods of this country. But little study on its taste compounds has been reported. This study was attempted to establish the basic data for evaluating taste compounds of fermented trepang entrails. Changes of free amino acids, free sugars, nucleotides and their related compounds as taste compounds during the fermentation of trepang entrails were analyzed by amino acid autoanalyzer and high speed liquid chromatography. Glutamic acid, alanine, glycine and proline were dominant amino acid in the fresh extracts, having 32.3%, 16.4%, 12.0% and 10.5% of the total free amino acid content, respectively. The content of leucine, valine, phenylalanine, isoleucine, methionine and tyrosine were low. The free amino acid were not changed in composition but changed in amounts during the fermentation of trepang entrails. Glutamic acid, alanine, glycine, proline, lysine, arginine and leucine were abundant in both fresh sample and fermented products. Free sugars in fermented trepang entrails, the results showed that galactose(933.7-988.0 mg%) was dominant and the content of arabinose, xylose were 78.7, 55.2-771mg% on moisture and salt free base respectively but glucose was detected in trace amount. Nucleotides and their related compounds were increased during the fermentation and hypoxanthine(47.1-$62.5{\mu}mole/g$, on moisture and salt free base) were dominant, IMP was abundant in fermented trepang entrails. TMA was increased while TMAO was decreased during the fermentation. The content of TMAO nitrogen in fermented trepang entrails was 30.0mg% on moisture and salt free base. The content of betine was increased during the fermentation and was ranged from 734.2 to 934.2mg% on moisture and salt free base. It is believed that such amino acids as glutamic acid, alanine, glycine, lysine, proline, arginine, leucine, such free sugars as galactose, arabinose, xylose, glucose, such nucleotides and their related compounds as IMP, hypoxanthine play an important role as taste compounds in fermented trepang entrails.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.247-258
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• 1994

A total of 31 commercial dried marine food products, consisting of 14 fishes, 2 shellfishes and 2 seaweeds species were analyzed for their contents of precusors of N-nitrosamine such as dimethylamine(DMA), trimethylamine(TMA), trimethylamine oxide (TMAO), betaine and nitrate and nitrite nitrogen as factors of N-nitrosamine formation. Carcinogenic N-nitrosamines were extracted by a steam distillation apparatus and were analyzed for their components using a gas chromatography-thermal energy analyzer. N-nitrosodimethylamine(NDMA) was confirmed by a gas chromatography-mass spectrometry. The contents of betaine nitrogen in samples were in the range of $5.2{\sim}373.8mg\%$ and were significantly higher than tertiary amines such as TMA and TMAO. DMA nitrogen in those samples was in the range of trace-31.2ppm and was high, in the dried shark(31.2ppm), alaska pollack($22.9{\sim}24.3ppm$) and octopus($17.9{\sim}18.4ppm$). In dried laver and sea mustard, however, amines were not detected at all. The levels of nitrate nitrogen in the dried marine samples ranged from zero to 16.8ppm and were high in the dried stingray(16.8ppm), alaska pollack(16.3ppm) and squid($2.2{\sim}12.4ppm$), but were less than 1.0 ppm in other samples. The levels of nitrite nitrogen were lower than those of nitrate nitrogen and it was not detected in dried sea cucumber, laver and sea mustard. Twenty eight of 31 samples contained NDMA($range=1.2{\sim}86.0ppb$), which was the only volatile N-nitroso compound found. The NDMA levels of dried stingray($2.8{\sim}86.0ppb$), alaska pollack($8.2{\sim}55.5ppb$), squid($3.3{\sim}53.2ppb$), yellow corvenia($45.9ppb$) and plain dried shrimp($15.4{\sim}17.9ppb$) were high. However, it was not detected in dried sea cucumber, laver and sea mustard. Samples, containing high levels of NDMA, also contained high nitrate and nitrite nitrogen. From above results, it can be concluded that nitrate and nitrite were major factors for the formation of NDMA in dried marine food products.