본 연구는 임하호의 고탁수 발생에 따른 식물플랑크톤군집의 변화를 조사하기 위하여 2003년 5월부터 2004년 7월까지 댐축 지점에서 매월 채집하였다. 2003년 9월과 10월의 가장 높은 탁도(1221 NTU) 형성은 태풍(매미)에 동반된 집중 호우 시기와 일치하였다. 출현한 식물플랑크톤은 모두 102분류군이고, 이 중 규조강이 63종류로 가장 많이 출현하였으며, 녹조강이 23종류, 남조강이 9종류, 시누라조강과 은편모조강이 각각 3종류 그리고 유글레나 조강이 1종류가 출현하였다. 총 현존량은 270~4,515 indls. mL-1였고, 은편모조강의 Cryptomonas ovata, 규조강의 Cyclotella sp. 그리고 남조강의 Microcystis aeruginosa 등은 고탁수의 감소후 차례로 우점하였다.

동아시아 지역에서의 원자력 수요는 경제 발전을 뒷받침하기 위해 급격히 증가하고 있다. 9.11 사태 이후 전 세계적으로 핵비확산은 세계적인 현안이 되고 있으며 이와 함께 타 지 역과는 달리 동아시아 지역에서는 향후 10년 후 몇몇 국가들이 원자력을 새로이 도입하려는 움직임이 있다. 이와 같은 현안에 대처하기 위해 공급 확약과 핵비확산을 목적으로 새로운 지역적인 다자간 원자력 협력 체제가 제안되었다. 이러한 새로운 제안은 신뢰성 증진, 자발적 참여 및 동기 부여의 원칙을 바탕으로 하고 있다. 또한 동아시아에서 다자간 체제를 실행하기 위해 단계적인 접근 방법을 제안하고 있다.

This research examines how various dimensions of physical environments influence patrons' psychological responses(especially emotional responses) in the restaurant service setting, and how these emotional responses, in turn, influence patrons' attitude formation. The result of empirical research indicates that restaurant physical environments have a significant effect patrons' emotional responses, and that these psychological experiences serve as critical mediators in the restaurant physical environments-store attitudes relationship. However, the effects of restaurant physical environments on patrons' psychological responses varied with the dimensions of physical environments. First, the effect of cleanliness on emotional responses was most significant, especially on negative emotion, out of 4 dimension of restaurant physical environment. Second, ambient conditions are the most important predictor on customers' positive emotion, and in turn, positive emotion has the most significant effects on customers' attitude formation of restaurant. Therefore, the result suggests that restaurants should manage(or, improve) their ambient conditions(e.g. background music, scents, ventilation, noise etc.) for efficiently maximizing customers' positive attitude. The implications of this study are discussed, and ideas for future work suggested.

We present a photometric study of galaxies in the central regions of six nearby galaxy clusters at redshift z=0.0231~0.0951. We have derived BVI photometry of the galaxies from the CCD images obtained at the Bohyunsan Optical Astronomical Observatory (BOAO) in Korea, and JHKs photometry of the bright galaxies from the 2MASS extended source catalog. Comparing the galaxy photometry results with the simple stellar population model of Bruzual & Charlot (2003) in the optical & NIR color-color diagrams, we have estimated the ages and metallicities of early type galaxies. We have found that the observed galaxies had recent star-formation mostly 5 ~ 7 Gyrs ago but the spread in age estimation is rather large. The average metallicities are [Fe/H]=0.l~0.5 dex. These results support the hypothesis that large early type galaxies in clusters are formed via hierarchical merging of smaller galaxies.

The objective of this study was to examine the effect of EGF on meiotic maturation and pronuclear (PN) formation of porcine oocytes. Prepubertal gilt cumulus-oocyte-complexes (COCs) aspirated from 2~6mm follicles of abbatoir ovaries were matured in TCM199 containing 0.1mg/ml cysteine, 0.5㎍/ml FSH and LH, and EGF (0, 5, 10, 20, 40 ng/ml) for 22 hr at 39℃ in a humidified atmosphere of 5% CO2 in air. They were then cultured for an additional 22hr without hormones. In Experiment 1, to examine the nuclear maturation at 44hr of culture, the expanded cumulus cells were removed by vortexing for 1 min in 3 mg/ml hyaluronidase. The oocytes were fixed in acetic acid: methanol (1:3, v/v) at least for 48 hr and stained with 1% orcein solution for 5 min. Nuclear status was classified as germinal vesicle (GV), germinal vesicle breakdown (GVBD), prophase-metaphase I (PI-MI), and PII-MII under microscope. In Experiment 2, to investigate PN formation, oocytes were fertilized with Percoll-treated freshly ejaculated sperm (1 x10 5 cells/ml) in mTBM with 0.3% BSA and 2mM caffeine for 5hr, and cultured in NCSU-23 medium with 0.4% BSA. At 6hr of culture, the embryos were fixed in 3.7% formaldehyde for 48hr and stained with 10ug/ml propidium iodide for 30 min. PN status was classified as no or one PN (unfertilized), 2 PN (normal fertilized) and ≥3 PN (polyspermy). Differences between groups were analyzed using one-way ANOVA after arc-sine transformation of the proportional data. The rate of oocytes that had reached to PII-MII were significantly (P<0.05) higher in all groups added EGF than that of non-treated group (67%), but it did not differ among the all added groups (86%, 85%, 79% and 81%, in 5, 10, 20 and 40 ng/ml EGF, respectively). No differences on the incidence of 2PN were observed in all treated groups (25%, 30%, 33%, 29% and 29%, in 0, 5, 10, 20 and 40 ng/ml EGF, respectively), however, in non-treated group, polyspermy tended to be increased (66% vs 58%, 54%, 52% and 55%, 0 vs. 5, 10, 20, 40 ng/ml EGF, respectively). These results suggest that EGF can be effectively used as an additive for enhancing oocyte maturation and reducing the incidence of polyspermy in pig.

Taguchi methodology has been applied to get an idea about the parameters related to the chemical vapour deposition technique, which influences the formation of semiconducting carbon thin film of a desired band gap. L9 orthogonal array was used for this purpose. The analysis based on Taguchi methodology suggests that amongst the parameters selected, the temperature of pyrolysis significantly controls the magnitude of band gap (46%). Sintering time has a small influence (30%) on the band gap formation and other factors have almost no influence on the band gap formation. Moreover this analysis suggests that lower temperature of pyrolysis (≤ 750℃) and lower time of sintering (≤ 1 h) should be preferred to get carbon thin film with the desired band gap of 1.2eV.

전기투석 공정에서 이온교환막 표면에 형성되는 스케일 영향을 조사하기 위해 장기간 동안 운전되었다. 탈염공정 동안, Ca2+과 SO42- 이온의 농도는 농축실에서 연속적으로 증가하였으며 양이온교환막(Neosepta CMX)표면에 침전이 발생하였다. 초기 스케일 형성동안, 공정성능과 막 특성의 변화는 농축실 염농도 증가에 기인하여 일어나는 양이온교환막의 하계전류밀도가 감소하는 것을 제외하곤 미미하였다. 공정운전이 진행됨에 따라 양이온교환막의 한계전류밀도는 물의 해리 현상이 진행되어 300;A/m2까지 감소하였다. 막 오염은 농축실에서 양이온교환막 표면에 형성된 스케일과 물의 해리현상에 의해 유발된다는 결론을 얻었으며, 이러한 스케일 형성은 CaSO4의 용해도에 의해 예측 가능한 것을 알 수 있었다.

This paper presents the application of integrated mathematical programming approach for the design of cellular manufacturing. The proposed approach is carried out in two phases: The first phase concerning exceptional elements(EEs) in cell formation and th

동해의 심층수 형성은 크게 대륙주변부 대류와 외양대류에 의한 것으로 알려져 있다. Vladivostok 연안과 subpolar front사이에서 겨울철에 발생하는 심층수의 형성은 외양대류에 의한 가능성이 높은 것으로 설명되고 있으며, 침니 현상이 이러한 결과를 됫받침 하고 있다. 본 논문에서는 외양대류에 의한 심층수 형성과정의 초기단계 즉 침니 현상의 전 단계에 나타나는 현상을 포텐셜 와도, 지형류, 수온, 염분, 용존산소의 분포로부터 확인하였다. 포텐셜와도의 분포에서 나타난 와동류는 Vladivostok 연안과 subpolar front 사이에 위치하며, 와동류의 분포 위치는 겨울철 심층수 형성 가능성이 높은 해역과 잘 일치한다. 특히 대륙의 지형적인 특성으로 인한 바람장의 변화는 본 연구에서 나타난 시계반대방향의 와동류가 형성될 수 있음을 보여주며, 그 결과로 나타나는 dome 구조의 밀도 분포는 외양대류의 초기 단계에서 나타나는 현상을 잘 보여준다.

In order to investigate the formation of AlN, mechanical alloying was carried out in and atmosphere. Differential thermal analysis (DTA), x-ray diffraction (XRD) and chemical analysis were carried out to examine the formation behavior of aluminum nitrides. No diffraction pattern of AlN was observed in XRD analysis of the as-milled powders in atmosphere. However, DTA and chemical analysis indicated that the precursors for AlN were formed in the Al powders milled in atmosphere. The AlN precursors transformed to AlN after heat treatment at and above . It was considered that the reaction between Al and was possible by the formation of fresh Al surface during mechanical alloying of Al powders.

A formation of aluminum hydroxide by hydrolysis of nano and micro aluminum powder has been studied. The nano aluminum powder of 80 to 100 nm in diameter was fabricated by a pulsed wire evaporation (PWE) method. The micro powder was commercial product with more than in diameter. The hydroxide type and morphology depending on size of the aluminum powder were examined by several analyses such as XRD, TEM, and BET. The hydrolysis procedure of micro aluminum powder was different from that of nano aluminum powder. The nano aluminum powder after immersing in the water was transformed rapidly to a nano fibrous boehmite, accompanying with a remarkable temperature increase, and then further transformed slowly to a stable bayerite. However, the micro powder was changed to the stable bayerite slowly and directly. The formation of fibrous aluminum hydroxide from nano aluminum powder might be due to the fine cracks which were formed by hydrogen gas pressure on the surface hydroxide layer during hydrolysis. The nano powder with large specific surface area and small size reacted more actively and faster than the micro powder, and transformed to meta-stable hydroxide in relatively short reaction time. Therefore, the formation of fibrous boehmite is special characteristic of hydrolysis of nano aluminum powder.