• Korean Journal of Ichthyology
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• v.20 no.4
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• pp.255-262
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• 2008

The endemic Korean stumpy bullhead Pseudobagrus brevicorpus is a first-grade endangered wild fish as designated by the Ministry of Environment of Korea. As part of its restoration and proliferation effort, a histological study of this fish was carried out to investigate sex differentiation and gonadal development based on F1 generation individuals obtained by artificial breeding. On days 4~5 after hatching, a pair of genital ridges including clusters of primordial germ cells was observed between the gut and the mesonephric duct. On days 20 after hatching, the ovary began to initially differentiate and contained early oocytes with chromatin-nucleolus and peri-nucleolus stages on days 30~40 after hatching. As yolk material accumulated after day 80 from hatching, the oocytes grew increasingly large and were surrounded by a distinct follicular layer. On days 306 after hatching, the oocytes grew toward a mature ovum. In the males, the testis was distinguished by emergence of spermatogonium cells on 25 days after hatching, and day 40 after hatching it contained a small number of seminal lobes forming cysts. From 173 days after hatching, the testis consisted of numerous enlarged seminal lobes including spermatocytes and spermatids. Over 14 months after hatching, some seminal lumens were filled with spermatozoa.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.1
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• pp.79-84
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• 2007

In this paper, a fully-integrated low phase noise multi-band CMOS VCO using automatic level controller (ALC) and switched LC tank has been presented. The proposed VCO has been fabricated in a 0.13-um CMOS process. The switched LC tank has been designed with a pair of capacitors and two pairs of inductors switched using MOS switch. By using this structure, four band (2.986 ${\sim}$ 3.161, 3.488 ${\sim}$ 3.763, 4.736 ${\sim}$ 5.093, and 5.35 ${\sim}$ 5.887 GHz) operation is achieved in a single VCO. The VCO with 1.2 V power supply has phase noise of -118.105 dBc/Hz @ 1 MHz at 2.986 GHz and -113.777 dBc/Hz @ 1 MHz at 5.887 GHz, respectively. The reduced phase noise has been approximately -1 ${\sim}$ -3 dBc/Hz @ 1 MHz in the broadest tuning range, 2.986 ${\sim}$ 5.887 GHz. The VCO has consumed 4.2 ${\sim}$ 5.4 mW in the entire frequency band.

• Journal of the Korean Chemical Society
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• v.26 no.2
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• pp.65-72
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• 1982

STO-3G level computations were performed on n-propylamine, n-propylamine radical and cis-and trans-ethylene diamines in order to investigate structural contributions of (n${\pi}$/m) and (n-${\sigma}^*$) structures to the energy variations accompanying the conformational changes. It was found that (5${\pi}$/5) and (4${\pi}$/4) structures had attractive and repulsive nonbonded interactions, respectively, which were approximately additive. anti(n-${\sigma}^*$) structures had more stabilzing hyperconjugative interactions than syn(n-${\sigma}^*$) structures, but due to the large internuclear repulsion the net effect was destabilizing inthe former in contrast with the net stabilizing contribution in the latter. Moreover it was found that the stabilizing ${\pi}$-nonbond structure, (5${\pi}$/5) was always cooperatively reinforced by the more stabilizing anti(n-${\sigma}^*$) interaction, whereas the destabilizing (4${\pi}$/4) structure was accompanied by the less stabilizing syn(n-${\sigma}^*$) interaction. This type of cooperativity was found general through-bond interaction of the terminal lone pair lobes split the energy levels into two, $n_+ = \frac{1}{\sqrt{2}}(n_1 + n_2)$ and $n_- = \frac{1}{\sqrt{2}}(n_1 - n_2)$, the latter being the lower level, which can be shown using simple overlap patterns of the two lobes with a common vicinal ${\sigma}^*$ orbital.

• Korean Journal of Clinical Pharmacy
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• v.9 no.2
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• pp.81-87
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• 1999

췌장이식의 성공률은 지난 10년 동안 상당히 상승되었다. International Pancreas Transplant Registry에 따르면 1995년 이래 미국에서만 매년 1,000건 이상의 췌장이식이 실시되고 있다. 장기이식후 나타나는 급성 거부반응은 이식 후 6개월 이내에 가장 높은 빈도수로 나타난다. 췌장이식환자에서는 신장을 이식한 것보다 두배나 높은 거부반응을 나타나며 이로 인한 입원율의 증가 항림프제(antilyinphocyte) 사용과 감염의 증가로 이환율이 높다. 더구나 Cyclosporine (CsA)을 기초로 한 면역억제제요법의 사용은 높은 급성 거부반응률(acute graft rejection)을 초래하여 이식한 장기의 조직손실이 문제가 되고 있다. 새로운 면역억제제인 Tacrolimus (FK506)의 사용은 이식환자에서의 거부반응을 감소시켜 생존율을 증가시키는 것으로 알려져 있다. Tacrolimus는 neutral macrolide로 cyclic peptide인 CsA과는 화학 구조는 매우 다르나 비슷한 면역억제 효과를 보인다. 하지만 Tacrolimus의 사용시 신경독성, 신독성, 특히 고혈당증의 발생률이 높아 일부 이식센터에서는 장기 이식 후에 사용하기를 꺼리기도 한다. 하지만 여러 연구논문에서 간과 신장 이식 후 급성 거부반응 예방에 Tacrolimus는 CsA에 비해 이점이 있는 결과를 발표하였다. 결과적으로, 현재 췌장이식 후 Tacrolimus를 기초로 한 면역억제의 효과에 대한 연구가 활발히 진행중이다. 따라서 본 연구에서는 1994-1996년 사이에 Tacrolimus 또는 CsA를 기초로 한 면역억제요법을 투여 받은 췌장이식환자 101명을 후향적으로 조사하여 Tacrolimus (n=54)와 CsA(n=57)의 급성 거부반응 예방 효과와 신부전 발생률을 비교하였다. 모든 환자는 항림프구 약물, Azathioprine, Prednisone을 이식 후 면역억제제로 투여 받았다 기준선으로부터 $20\%$ 이상의 혈청 creatinine의 상승이 있는 환자에서는 급성 신부전으로 정의하였고 신장생검법으로 거부반응을 진단하였다 Matched-pair analysis에 따르면 췌장이식환자의 6개월 생존율은 CsA군에서 $97\%$, Tacrolimus군에서 $96\%$로 별다른 차이가 없었으며 (p=0.57), 6개월간의 이식한 췌장의 보존율은 CsA군에서는 $88\%, Tacrolimus에서 $91\%$. 유의한 차이는 없었다(p=0.29). 췌장이식 후 6개월 동안 Tacrolimus의 사용은 생검으로 증명되는(biopsy-proven) 급성 거부반응의 발생빈도는 CsA보다 유의하게 낮았을 뿐만 아니라 (p<0.05) 거부반응 증상의 심각도 또한 감소시켰다 (p=0.03). 급성거부반응 발생빈도의 감소로 Tacrolimus군에서 antilymphocyte 치료가 유의하게 줄어들었다(p=0.01). CsA군에서 Tacrolimus보다 신부전의 발생률이 높았으나 통계학적 차이는 없었다. 췌장이식후의 최적의 면역억제요법의 결정하기 위해서는 향후 Tacrolimus와 CsA을 비교하는 전향적 무작위 연구가 필요하다.

• Sleep Medicine and Psychophysiology
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• v.15 no.1
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• pp.39-43
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• 2008

Objectives: The pathophysiology of restless legs syndrome (RLS) is not obvious, but many promising theories involve dopaminergic deficiency and genetic causes. The RLS is presumed to occur more frequently among schizophrenic patients who take antipsychotics, most of which blocks the dopamine receptors. This study aimed to investigate whether dopamine transporter gene (DAT1) 40 base pair (bp) variable number of tandem repeat (VNTR) polymorphism is associated with the antipsychotic-induced RLS in schizophrenia. Methods: We determined the diagnosis of RLS among the 190 Korean schizophrenic patients by the diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG). Genotyping was performed for the 40bp VNTR in DAT1 gene using polymerase chain reaction. Results: We separated the schizophrenic patients into 44 patients with RLS and 146 patients without RLS. The genotype and allele frequencies did not differ significantly between two groups. Conclusions: These results suggest that DAT1 gene 40bp VNTR is not associated with the antipsychotic-induced RLS in schizophrenia. To confirm these results, larger-scale association study is needed in the future.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.769-772
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• 2008

The problem of disposing construction waste materials has become a national and social problem. Recycled powder generated in the process of making aggregate, and the recycled powder is land-filled in its entirety. Results of toxicity testing of recycled power show that it contains base-pair substituent mutagenicity. As recycled powder is disposed of as landfill, it can cause secondary contamination such as soil and underground water contamination. There has been very little research made on recycled powder. This study has examined the utilization of concrete mixture by using recycled powder in a mixture instead of cement and compared and analyzed the characteristics of dynamics and workability. This study has examined the application of recycled powder in concrete. Depending on the replacement rate and workability, test piece was manufactured using different mixing rate by CP, WCP, PCP. The CP was used to examine the physical property of concrete and characteristics its dynamics. The letters W of WCP and P of PCP are the initials of water and mixture. They were made using the standard mixing ratiosemphasizing the workability to determine the characteristic of dynamics of concrete based on the mixing ratio of recycled powder. With the increase in the replacement rate, CP had very little change in the strength. But with the decline of slump, the workability was not good. The result of manufacturing WCP and PCP using the standard mixing ratio showed that WCP had a drop in strength compared to the plain. PCP had almost the same value as the plain only when the replacement rate was 10%. When it was higher than that, a reduction in strength was observed.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.29-36
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• 1991

Studies were carried out to investigate structural characteristics of the larval and adult light organs of Luciola lateralis Mot. and to observe the relation between the light organ and nerve. The larval light organs, (LLO)existed at a paired dorsal lateral positions of the 8th abdominal segment. The organ was spherical or sub-spherical in shape. There were many vacuoles around the LLO. As larva grew, the number of vacuoles increased. LLO had the muscles in its interior part and their role seemed to fix the LLO position in space. Also, there were the tracheae and tracheoles in LLO. The Adult light organs (ALO) were at the ventral portions of the 5th and 6th abdominal segments in the male, but only on the 5th abdominal segment in the female. ALO had two functional layers, i.e., photocyte and dorsal layer. Tracheal end organs existed in both layers but their arrangements were irregular. Rod-shaped photocytes and spherical photocytes were observed in the ALO of male and female, but the rod-shaped types were rarely found in the female. In the ALO of the 5th abdominal segment, two paired peripheral nerves were originated from the anterior part of the last abdominal compound ganglion. A pair of peripheral nerves were originated from the posterior part of the compound ganglion to innervate the 6th abdominal segment ALO. And LLO was innervated by a paired peripheral nerves from the last abdominal ganglion.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.936-942
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• 2018

The diagnostic multi-leaf collimator preventing unnecessary dose from entering into patients during the diagnostic examination was made in this study. The movement of the entire 50 leaves was embodied with the group of 25 ones thereof configured in a pair facing each other on the left and right of the median line. Dimensions of the length, width, and height of each shielding leaf were $5{\times}0.5{\times}0.5cm^3$ resulting in the maximum boost field of $10{\times}10cm^2$. The material of multi-leaf collimator had the excellence on the machinability with the use of the SKD-11 alloy tool steel having the high wear resistance against frequent movement, and it was devised to control both-side's shielding leaves by moving 2 motors unlike existing remedial multi-leaf collimator that use as many motors as the number of 50 shielding leaves. Thereafter, the transmission dose of leaves, cross-leaf leakage dose, and inter-leaf leakage dose were measured by the developed multi-leaf collimator attached to X-ray equipment. An ionization chamber was used to detect doses there from, and the comparative analysis was carried out by means of the radiographic film that was easy to detect the dose leakage in between each leaf. Results obtained from the test conducted in comparative analysis yielded approximately 98%, 96%, and 94% of shielding efficiency realized at each level of energy of 80kV, 100kV, and 120kV it was confirmed there was no dose leakage resulted from the varied level of irradiation energy. Thus the multi-leaf collimator to be developed based on this study is thought that it could fully reduce the unnecessary dose to patients in the diagnostic test and the shielding efficiency thereof is expected to be increasing if it is made in a miniaturized form with a way of increasing the thickness of each leaf later for an extended application to general diagnostic purposes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10B
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• pp.1150-1158
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• 2011

More than 100 Mbps rate is needed in the UBcN for a subscriber to receive broadband traffics with multi-channel like UDTV or 3DTV. Although the optical fiber is recently deployed for the FTTH, the UTP is the most widely used medium and will be used in UBcN age. Network providers may consider the 1000BASE-T or the vectorized VDSL if they adopts the UTP in the place where does not have optical fibers. But UTP should be expanded because 1000BASE-T and vectorized UTP needs 4 and 3 pairs cable, respectively while residential region has not exceeding 2 pair UTP cable. To solve the problem, we propose a 500BASE-T technology using 2 pairs UTP in this paper. The technology introduces a rate adaptation sublayer and a SERDES sublayer above and under the PCS, respectively. The rate adaptation sublayer is compatible for the GMII. Also, if we modify the SERDES sublayer, the technology can easily obtain 250BASE-T with 2 pairs UTP. We implement such functions with FPGA and analog board and verify the function of rate adaptation and symbol vector synchronization, and effective transmission rate by experiments. In particular, we show that link efficiency is increased by enable control in the rate adaptation sublayer.

• The KIPS Transactions:PartD
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• v.15D no.6
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• pp.767-776
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• 2008

Microarray technology is extensively being used in experimental molecular biology field. Microarray experiments generate quantitative expression measurements for thousands of genes simultaneously, which is useful for the phenotype classification of many diseases. One of the two major problems in microarray data classification is that the number of genes exceeds the number of tissue samples. The other problem is that current methods generate classifiers that are accurate but difficult to interpret. Our paper addresses these two problems. We performed a direct integration of individual microarrays with same biological objectives by transforming an expression value into a rank value within a sample and generated rank-comparison decision rules with variable number of genes for cancer classification. Our classifier is an ensemble method which has k top scoring decision rules. Each rule contains a number of genes, a relationship among involved genes, and a class label. Current classifiers which are also ensemble methods consist of k top scoring decision rules. However these classifiers fix the number of genes in each rule as a pair or a triple. In this paper we generalized the number of genes involved in each rule. The number of genes in each rule is in the range of 2 to N respectively. Generalizing the number of genes increases the robustness and the reliability of the classifier for the class prediction of an independent sample. Also our classifier is readily interpretable, accurate with small number of genes, and shed a possibility of the use in a clinical setting.