This study evaluated the efficiency and compared with different materials of loading vessels for vitrification-plastic/glass, copper grid and nylon. The loading method, vitrification, cryop-reservation and warming method of the oocytes were examined. The loading samples prepared in manual or company-made and sterilized, loaded the COCs selected on each samples and cultured for maturation during 40 hours, and then exposed sequentially to ethylene glycol solution. Thawing method was reversely treated and exposed for warmed oocytes. After oocytes were thawed, fertilized and cultured in vitro for 3-4 hours, rates of development and morphological appearance were examined. The results were as summarized: ㆍOPS from company-made or hand-made of the hematocrit micropipettes, NLS from fishing line and EMG from company-made for EM were used for loading oocytes, respectively. ㆍThe efficiency of freezing method and loading convenience were orderly higher in OPS, NLS and EMG. The optimal capacity per vessel was orderly lowered in NLS, EMG and OPS, respectively. ㆍAfter oocytes were warmed, the recovery rate, morphology and rate of development were orderly higher in OPS, NLS and EMG, respectively. ㆍIn conclusion, OPS has the advantages of achieving a little more survival and preserving results than other two loading methods.

이 연구는 인천시 공개공지의 조성과 이용실태 그리고 식재 현황을 분석하여 도심 녹지로서 기능을 개선하기 위한 방안제시를 목적으로 하였다. 연구대상지는 1994∼2002년 조성된 대형상업건물 10개소, 교통관련 건물 3개소, 공공기관 건물 2개소의 공개공지였으며, 우리나라와 유사한 공개공지 제도를 운영하고 있는 일본 오사카시와 가와사키시 공개공지의 식재지 구조를 인천시 연구대상지와 비교하였다. 인천시는 아직까지 공개공지를 도심 녹지로 보는 시각이 부족하였고 공개공지는 법적 의무만을 충족시키는 수준에서 조성되고 있었다. 공개공지의 도심녹지 기능 강화를 위해서는 첫째. 공개공지 식재지율을 어린이공원 수준인 40%로 늘려 소공원화 하는 것이 필요하다. 둘째, 공개공지의 수목 식재기반. 수종선정, 식재방법 등에 대한 사항을 인허가시 녹지관련 부서와 협의할 수 있도록 해야 한다. 셋째. 공개공지의 식재 기준으로 삼고 있는 '대지안의 조경 식재기준'을 현재 보다 상향 조정하여 녹지 질과 녹량을 증진시켜 환경개선 효과를 높일 수 있도록 해야 한다. 넷째. 공개공지를 시민들이 쉽게 알아보고 이용할 수 있는 안내 사인의 설치 의무화가 요구된다. 다섯째, 공개공지가 본래 목적 이외의 다른 용도로 전용되지 못하게 법적 규정을 마련할 필요가 있다.

Human embryonic stem (hES) cell lines have been derived from human blastocysts and are expected to have far-reaching applications in regenerative medicine. The objective of this study is to improve freezing method with less cryo-injuries and best survival rates in hES cells by comparing various vitrification conditions. For the vitrifications, ES cells are exposed to the 4 different cryoprotectants, ethylene glycol (EG), 1,2-propanediol (PROH), EG with dime-thylsulfoxide (DMSO) and EG with PROH. We compared to types of vehicles, such as open pulled straw (OPS) or electron microscopic cooper grids (EM grids). Thawed hES cells were dipped into sequentially holding media with 0.2 M sucrose for 1 min, 0.1 M sucrose for 5 min and holding media for 5 min twice and plated onto a fresh feeder layer. Survival rates of vitrified hES cells were assessed by counting of undifferentiated colonies. It shows high survival rates of hES cells frozen with EG and DMSO (60.8％), or EG and PROH(65.8％) on EM grids better than those of OPS, compared to those frozen with EG alone (2.4％) or PROH alone (0％) alone. The hES cells vitrified with EM grid showed relatively constant colony forming efficiency and survival rates, compared to those of unverified hES cells. The vitrified hES cells retained the normal morphology, alkaline phosphates activity, and the expression of SSEA-3 and 4. Through RT-PCR analysis showed Oct-4 gene expression was down-regulated and embryonic germ layer markers were up-regulated in the vitrified hES cells during spontaneous differentiation. These results show that vitrification method by using EM grid supplemented with EG and PROH in hES cells may be most efficient at present to minimize cyto-toxicity and cellular damage derived by ice crystal formation and furthermore may be employed for clinical application.

We present a study of the old open cluster Trumpler 5 (Tr 5), based on the CDS archival data. From the color-magnitude diagrams of Tr 5, we have found the positions of main-sequence turn-off (MSTO) and red giant clump (RGC) stars. Using the mean magnitude of the RGC stars, we have estimated the reddening toward Tr 5, E(B - V) = 0.60 ± 0.10. Using the stars common in two data sets and the theoretical isochrones of Padova group, we have estimated the distance modulus Vo - Mv = 12.64 ± 0.20 (d = 3.4 ± 0.3 kpc), the metallicity [Fe/H) = -0.30 ± 0.10, and the age of 2.4 ± 0.2 Gyr (log t = 9.38). These metallicity and distance values are consistent with the relation between the metallicity and the Galactocentric distance of other old open clusters, for which we obtain the slope of Δ[Fe/H]/ Rgc = -0.064 ± 0.010 dex kpc-1.

This study deals with how the Korean open treatment for prisoners in the 21st century should be implemented effectively. For this study, the historical trace of criminal policy theories and the correctional policies in Korea and the open treatment system in some other advanced countries were reviewed. The open treatment such as open facilities, work release system etc. has been extensively used in the developed countries and it has been generally successful in rehabilitating inmates effectively. In this context, the purposes of this study are to evaluate the current practices of the open treatment in our country and to make some recommendations for their improvement. In conclusion, this study aims at offering the progressive policies for the future open treatment system in Korea by searching for the effective and innovative programs based on my field experience of corrections for a long time.

The advantages of the OPS techniques(Vajta G et al, Mol Reprod Dev 51: 53-58,1998) give 1) high survival rates of various types of eggs, 2) quick and simple process, 3) inexpensive equipment and reduced chilling injury. The efficiency of IVM/IVF technique in the porcine species is relatively lower than that obtained in other species such as ruminants. Two experiments were designed to investigate the effects of in-vitro fertilization of porcine oocytes matures using different OPS protocol for chilling and warming of vitrification. Porcine oocytes from ovaries collected at abattoir were matured for 44 hours in TCM199 Earle's salt supplemental with pyruvate, pff, L-cysteine, hormones and gentamycin. Oocytes were denuded and fertilized with frozen boar semen by common method. Porcine embryos produced routinely by in-vitro culture system of NCSU23 medium. The vitrification and the warming were conducted by OPS method with the glass micropipette instead of straw vessels and modified the protocol of G.Vajta(1999). In Exp 1, Chilling/Warming:Holding Medium(HM)+EG+DMSO/HM +sucrose Medium(SM) at 39 warm stage. In Exp 2, : PBS+CS+EG+Ficoll+ Trehalose/PBS+Trehalose at 25 stage. Filling, freezing, packing, thawing out and further culturing were performed to follow the basic protocol of G Vajta. During IVM-lVC and post-warming, fertilization parameter and developmental potential were compared to and statistically analysed. It was not significantly different from Exp 1 and Exp 2 but 25 of stage was slightly higher on the morula/blastocyst forming rate and better atmosphere for worker than that at 39 stage.

We have conducted VI CCD photometry of the open cluster NGC 6819 in order to understand the effects of dynamical evolution in old open clusters. Our photometry covers 18'× 18' on the sky, centered on the cluster, which seems to cover the whole cluster field. Our photometry reaches down to V ≈ 20.5, which allows us to analyze the luminosity function and spatial distribution of stars brighter than Mv ≈ 8.5. There is a clear evidence for mass segregation in NGC 6819, i.e., the giants and upper main-sequence stars are concentrated in the inner regions, whereas the lower main-sequence stars distribute almost uniformly throughout the cluster. The luminosity function of the main-sequence stars of NGC 6819 is almost flat. The flat luminosity function indicates that a large number of low mass stars has escaped from the cluster unless its initial mass function is much different from the Salpeter type (Φ(m)∝ m-(1+x),x = 1.35).

We have conducted UBVI CCD photometry of an intermediate-age open cluster NGC 559 to investigate the effect of dynamical evolution on the stellar distributions in NGC 559. Our photometry allows better estimates of distance and age of the cluster owing to much deeper photometry (V ≤ 21) than previous ones. It is found that the luminosity function and mass function as well as the spatial stellar distributions are affected by the dynamical evolution. Mass segregation leads to the central concentration of the high mass stars, which results in the flattened mass function inside the half mass radius.

UBV RI and Hα photometry has been performed for the open cluster NGC 6531. A total of 56 bright main sequence (MS) members were selected from their positions in photometric diagrams. We also classified 7 pre-main sequence (PMS) stars and 6 PMS candidates with Hα emission from Hα photometry. We determined a reddening of < E(B - V) >= 0.29 ± 0.03 and a distance modulus of Vo - Mv = 10.5 for the cluster. From the comparison of our photometric results to theoretical evolution models, we derived a MS turnoff age of 7.5 Myr and a PMS age spread of ~4 Myr. The IMF slope Γ, calculated in the mass range of 0.45 ≤ log m ≤ 1.35 is a steep value of Γ = -1.8 ±0.6.

UBVI CCD photometry of open cluster NGC 2324 is presented. C-M diagrams of this cluster show well-defined main sequence with a red giant clump centered at B - V =1.05, V =13.45. We derived the major cluster characteristics; E(B - V)=0.17±0.12 from color-color diagram and mean color of red giant clump stars, (m - M)o=13.1±0.1 from zero age main sequence fitting, and [Fe/H]~-0.32 from comparison the theoretical model developed by Bertelli et al. (1994) to the observed C-M diagrams. We estimate the age of NGC 2324 to be log t~8.8 by applying isochrone fitting and morphological age index method.

We derive a new relationship between the giant branch slope as measured in the color-magnitude diagram (K, J - K) and [Fe/H] metallicity for old open clusters. Previously such relationships have been derived for globular clusters, while similar tendency has been expected for open clusters. New derived correlation, [Fe/H]=-17.2(±0.23)GB slope - 1.95(±0.02), is based on a collection of data for 10 old open clusters. Most clusters behave as expected from the theoretical predictions.

The purpose of this paper is to solve the problem that is occuring in assembly process and to progress the productivity by process analysis methods for manu-open and closed model(DWV-20/25DRG), and auto-open and cloesd model(DWV-20/25/DRA)-ventilation fan. Also, this paper is studied by data of ＇D＇ company's product.

본 연구는 OPS 방법에 의한 돼지미성숙 및 성숙난자의 동결-융해 후 난자의 생존성에 있어서 난구세포의 영향을 검토하였다. 그 결과 미성숙 난자의 동결-융해 후의 성숙율은 난구세포의 부착 (25%) 및 제거 (15%)시 유의적인 차이는 인정되지 않았지만 control group (62%)에 비해서는 유의적으로 낮게 나타났다(P<0.05). 미성숙난자의 동결-융해 후 체외성숙시킨 난자의 체외수정시 난구세포 제거시 (19%), 부착된 (9%) 난자에 비해

복합재 적층판은 중량에 비해 높은 강성과 강도가 요구되는 공학의 다양한 분야에서 매우 유용하다. 보강섬유 복합재의 공학적 활용이 활발해지고, 중량의 감소화가 설계의 중요한 목적이 됨으로써, 근래 복합재 구조물들의 최적화 설계의 중요성이 대두되고 있다. 그러나 복합재 적층 구조물 재료의 비등방성에 의해 해석과 설계가 매우 어렵다. 본 연구에서는 수치적 최적화 방법과 유한요소법을 이용하여 보강섬유 복합재의 최적설계를 하였다. 복합재 적층판으로 이루어진 개단면 보에 있어서 보강섬유의 다양한 적층방향에 대한 거동의 영향을 규명하였다.