• Korean Journal of Materials Research
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• v.10 no.12
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• pp.853-863
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• 2000

In this study, a new UBM materials system for solder flip chip interconnection of Cu pads were investigated using electroless copper (E-Cu) and electroless nickel (E-Ni) plating method. The interfacial reaction between several UBM structures and Sn-36Pb-2Ag solder and its effect on solder bump joint mechanical reliability were investigated to optimife the UBM materials design for solder bump on Cu pads. Fer the E-Cu UBM, continuous coarse scallop-like $Cu_{6}$ $Sn_{5}$ , intermetallic compound (IMC) was formed at the solder/E-Cu interface, and bump fracture occurred this interface under relative small load. In contrast, Fer the E-Ni/E-Cu UBM, it was observed that E-Ni effectively limited the growth of IMC at the interface, and the Polygonal $Ni_3$$Sn_4$ IMC was formed because of crystallographic mismatch between monoclinic $Ni_3$$Sn_4$ and amorphous E-Ni phase. Consequently, relatively higher bump adhesion strength was observed at E-Ni/E-Cu UBM than E-Cu UBM. As a result, it was fecund that E-Ni/E-Cu UBM material system was a better choice for solder flip chip interconnection on CU PadS.

• Journal of the Korean Magnetics Society
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• v.10 no.5
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• pp.196-202
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• 2000

Top synthetic spin valves with structure Ta/NiFe/CoFe/Cu/CoFe(P1)/Ru/CoFe(P2)/FeMn/Ta on Si(100) substrate with natural oxide were prepared by dc magnetron sputtering system, and investigated on the magnetoresistance properties and effective exchange bias field. As the thickness of FeMn increased above 150 $\AA$, MR ratio was decreased due to the current shunting effect. As the thickness of free layer decreased below 40$\AA$, MR ratio was reduced rapidly. In case of 40 $\AA$ thick of free layer, spin valve film with a structure Si(100)/Ta(50 $\AA$)/NiFe(27 $\AA$)/CoFe(13 $\AA$)/Cu(26 $\AA$)/CoFe(30 $\AA$)/Ru(7 $\AA$)/CoFe(15 $\AA$)/FeMn(100 $\AA$)/Ta(50 $\AA$) exhibited maximum MR ratio of 7.5 % and an effective exchange bias field of 600 Oe, respectively. Thickness difference dependence in this synthetic spin valve structure on effective exchange field was investigated and interpreted by the analytical method. It should be noted that thickness increase of CoFe(P 1) and decrease of CoFe(P2) in synthetic antiferromagnet leaded to the decrease in effective exchange bias field by experimentally and analytically.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.280-283
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• 2010

A new standard rose cultivar 'Noble Red' was bred by the cross between the pink standard cultivar 'Silba 87' and the red standard cultivar 'Bravo' at the National Institute of Horticultural and Herbal Science. The cross was made in 1999 and 'Noble Red' was finally selected in 2003 after investigating the characteristics such as flower Color, Fragrance, stem length, stem diameter, weight, and number of leaves for three years from 2001 to 2003. 'Noble Red', a red standard cultivar grows vigorously and has good flower shape. The major characteristics of this cultivar are $125stems/m^2/year$ in yield, 71.9 cm in length of cut flower, 6.0cm in flower diameter, 30.8 in petal number, and 9.2 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cultivar, 'Rote Rose'.

• International Area Studies Review
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• v.15 no.1
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• pp.469-493
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• 2011

This paper attempts to examine the economic impact of technological barrier to trade(TBT) between Korea and China by using international input-output approach. With the tariff/quota reduced or eliminated since WTO's launch, the interest in TBT as a non-tariff barrier has been increased, and then there have so far been a large number of empirical studies on quantifying its effect in foreign. But still this area of study in Korea is limited in the literature survey. In encouraged in this situation, focusing on bilateral trade between Korea and China, which has been significantly increased in recent years, we have tried to estimates the impact of TBT on their output and employment. We use Asian International Input-Output Table(AIIO) for the year 2000 published by IDE-JETRO, and also use the estimated sectoral TBT provided by Ha et al.(2010). According to the result, there will be generated $3.63 billions values in outputs, and 18.1 millions persons in employments at most. And also we found that there is weak interdependence in sectoral and spatial linkage between two countries.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.11 no.1
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• pp.79-90
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• 2000

Objective：This study was performed in order to develop a measuring instrument for assessing and predicting delinquent behavior of the adolescents in Korea. Methods：This study was methodological research for developing a questionnaire for measuring delinquent behavior. Through the relevant literature review and personal interview using open-ended question with 12 adolescents in schools, outpatient basis and the juvenile corrective institutions, the author developed a pre-questionnaire with 31 items for assessing delinquent behavior among delinquentprone adolescents. Statistical method employed were test-retest reliability and Cronbach's alpha coefficient for testing reliability and factor analysis for testing validity of this questionnaire, and t-test for mean difference between student adolescents and delinquent adolescents, using SAS program. Subject served for this study consisted of 2,177 adolescents including 1,206 students and 971 delinquent adolescents by proportional stratified random sampling method. Results：1) Three stable factors were emerged and these contributed 52.2% of the variance in the total score. All 31 items loaded above .40 on each factor. 2) Factor I was named as antisocial delinquent behavior(17 items), factor II was named as aggressive delinquent behavior(8 items), and factor III was named as psychopathic delinquent behavior(6 items). 3) Comparison of these 3 factors between student adolescents and delinquent adolescents showed that there was a significant difference in factor Ⅰ(t=-42.91(student), -41.71(delinquent), p=.0001), factor II(t=-34.10(student), -35.72(delinquent), p=.0001), factor III(t=-14.24(student), -14.26 (delinquent), p=.0000), and total score(t=37.02(student), -36.38(delinquent), p=.0001). 4) Internal consistency reliability was tested by Cronbach's ${\alpha}$. Cronbach's ${\alpha}$ was .952 for total 31 items and .950, .866 and .721 for each 3 factors related to delinquent behavior. Conclusions：The author confirmed that this scale can use for measuring delinquent behavior, and hope to make a contribution to screening test and prevention of juvenile delinquency in Korea.

• Journal of Embryo Transfer
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• v.22 no.1
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• pp.53-61
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• 2007

This study was investigated factors affecting the pregnancy rates after transfer of pronuclear microinjected embryos for the production of transgenic Korean black goats. Embryo transfer was carried out in 343 recipient Korean black goats from September 1999 to June 2000. Estrus was induced by the insertion of intravaginal progesterone devices $CIDR^(R)$ for 2 weeks. A single injection of 400 IU equine chorionic gonadotropin was administered at 48h before $CIDR^(R)$ removal to increase the proportion of does cycling and ovulation rate. Good quality embryos were prepared by microinjection of DNA into the pronuclei of fertilized goat oocyte and cultured in vitro. Pronuclear microinjected $1{\sim}8$ cell stage embryos were surgically transferred into the oviducts of the recipient at day 4 or 5 following $CIDR^(R)$ removal, and morula to blastocyst stage embryos were surgically transferred into uterus at day 9. Pregnancy was diagnosed by transrectal ultrasound scanning at $20{\sim}30d$ and 8 weeks following embryo transfer. The pregnancy rate was affected by several factors, such as estrus induction, the number of previous transfer, transfer site, stage of CL (corpus luteum), the number of recipient CL, stage of embryos and the number of transferred embryo. The pregnancy rate was significantly higher in recipients that came into estrus naturally than recipients that induced to come into estrus with $CIDR^(R)$(59.1% vs. 36.8%; P<0.05). The pregnancy rate was higher when the embryos were transferred into the left oviduct than transferred into the right oviduct (42.9% vs. 35.3%; P<0.05). The pregnancy rate of recipients with $CH_1$ (early) stage corpus hemorrhagicum in ovary was hi틴or than recipient with $CH_3$ (late) stage hemorrhagicum (47.5% vs. 17.9%; P<0.01). Higher pregnancy rates were obtained by transfer of 1-cell stage embryos into oviduct while late blastocysts (51.6% vs. 66.7%; P<0.01) into uterus. The pregnancy rates when 3 embryos were transferred to recipients were significantly higher than when 2 embryos we.e transferred (47.6% vs. 27.0%; P<0.05). Although there were no significant difference among the group, adhesion of reproductive organs, uterine size, ovulation rate of recipients, presence of large follicle and difficulty of transfer affected pregnancy rate of recipient. Higher pregnancy rates were obtained in the recipients with $8{\sim}15m$ diameter uterine horn as compared to the recipients with <5m diameter or >20mm diameter uterine hem (38.9%, 20% vs. 18.2%), in the recipients with large follicle in the ovulated ovary ipsilaterally (53.6% vs. 37.1%) and in the transfer which was carried out easily (39.2% vs. 27.8%, 0%). In conclusion, the high rate of pregnancy was achieved following transfer of pronuclear microinjected embryos when three or four 1-cell stage embryos were transferred into oviduct with $CH_1$ stage corpus hemorrhagicum in the ovary of recipient which came into estrus naturally.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.21-28
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• 2000

The biological activities of water, ethanol and 50% ethanol extracts from Acanthopanax root bark were compared. 94% of Hep3B cell growth was inhibited by adding 1.0g/L of 50% ethanol extracts from A. senticosus root bark. It was also showed that above 90% of A549 cell growth was inhibited by adding 1.0g/L of 50% ethanol extracts. The 50% ethanol extracts of A. sessiliflorum root bark showed that the extracts selectivity were from 1.5 to 3.4 by adding all samples. For screening immunomodulating activities, Jurkat(T-cell) was showed that the cell growth and viability were more increased and activited 275% by adding the 50% ethanol extracts from A. senticosus root bark. The result of anti-mutagenicity of 50% ethanol extracts of A. senticosus root bark was most effective than any other samples. The enhancement of glutathione-S-transferase activity was increased 241% by adding 1.0g/L 1 : 1 extracts of A. senticosus root bark. 72% of oxidation was inhibited by adding 1.0g/L of 50% ethanol extracts from A. senticosus root bark.

• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.763-771
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• 2000

Objectives : Thoracolumbar burst fractures(TBLF) result in not only compressive deformity of vertebral body but also spinal cord compression by bony fragments. Many thoracolumbar burst fractures demand both anterior decompression and intervertebral fusion. Most of spinal surgeons use anterior instrumentation for anteior intervertebral bony fusion. The use of Z-plate has been increased recently, however there has been only a few reports regarding its clinical long-term strength. We studied nineteen patients with TBLF to find out the long-term stability of Z-plate. Methods : We have operated 19 patients from March 1996 to August 1998. They were treated with anterior decompression through either a transthoracic, retroperitoneal extrapleural or retroperitoneal approach. Retropulsed bony fragments were removed completely by corpectomy. Iliac bone graft was used for interbody fusion in all of the cases. They were evaluated by plain X-ray films including flexion and extention lateral films. Cobbs angle was used to evaluate kyphotic and lateral wedging deformity. Results : Burst fractured sites were T11 in two, three T12, nine L1, and five L2. Mean follow-up duration was fifteen months. Preoperative average kyphotic angle was 23.7 degree. Immediate postoperative kyphotic angle was 10.2 degree. Follow-up resluts of average kyphotic angles revealed 14 degrees. Four patients(21%), including two spinal 3-column injury, showed increasement of kyphotic angle more than 5 degree or breakage of intrumentation. Two patients showed the difference of kyphotic angle more than 3 degree. Five patients(26%) revealed lateral wedging deformity more than 3 degrees. Postoperative complications were two meralgia parestheticas, one pulmonary atelectasis and two donor site infections. Four of the eight patients, who initially showed incomplete spinal cord deficits, were nerologically improved by Frankel's grade. Conclusion : Z-plate fixation and iliac bone graft after anterior decompression in thoracolumbar burst fractures is a safe and easy method. Immediate postoperative results revealed excellent correction of posttraumatic kyphosis, but long-term follow-up evalution showed insufficient strength. Therefore we believe that use of Z-plate should be carefully decided, especially in the case of large lumbar fracture or 3-column injury.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.318-321
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• 2000

이 연구는 정보통신기기 수출량에 관해 하향식(Top-down) 방법에 기초한 예측 모형을 제시한다. 하향식방법은 전체 수출량과 전체를 구성하는 개별 항목간에 계층적 관계를 바탕으로 순차적으로 예측을 수행하는 방법이다. 전체와 개별 항목간에 관계는 데이터의 시계열 특성과 데이터에 영향을 주는 요인들에 의해서 만들어진다. 이러한 관계를 바탕으로 하는 하향식 예측은 전체 수출량을 먼저 예측한 후 이 예측치를 바탕으로 하여 개별 항목에 대한 예측을 수행한다. 하지만 하향식 방법은 가장 아래 계층의 예측치를 산출하기 위해 필요한 것이며 최종 예측치는 가장 마지막 계층에서부터 예측 데이터를 합산해서 얻을 수 있다. 결국 하향식 예측 방법은 전체와 개별 항목 사이에 상관관계가 높고 계층화되어 있는 구조에 적합하다. 이 예측 대상이 되는 정보통신기기 수출량에 대한 적용 사례를 살펴보자. 계층 구조를 보면 정보통신기기 전체 수출량과 전체를 구성하는 개별 항목으로 정보통신기기 분류별(유선기기, 무선기기, 방송기기, 정보기기, 기타부품기기)과 국가별(미국, 일본, 중국 등 7 개국)로 나뉘어진다. 다시 이 아래 계층으로는 국가와 정보통신기기의 행렬 구조(예: 미국-유선, 일본-부품 등)에 의해 35 개로 나뉘어진다. 각 단계별 예측 방법을 보면 전체 수출량은 시계열 특성과 거시적 변수를 반영한 시계열 모형, 그 아래 계층인 국가별과 분류별 모형에는 전체 수출량 시계열 특성과 국가별과 분류별에 영향을 주는 관련 변수를 반영한 회귀모형 그리고 행렬 구조에 대한 예측은 상위 계층의 시계열 특성과 행렬구조 데이터의 계절성이 반영된 다중 회귀모형을 이용하였다.ndex, mobile user′s will first be classified by their traffic volume, and then calculate the average tariffs per minute of each group of users, and lastly weight-average those tariffs per minute. And finally, this paper shows the mobile tariff index by considering those averaged tariffs and the carriers′ market shares to reflect the contribution of individual carriers and the users′ traffic volume.완화될 수 있다. 즉, 봉지를 씌웅으로서 봉지 내의 대기 환경이 외기보다 안정적으로 유지되고 직사광선이나 농약 및 마찰로부터 과실을 보호해 주기에 동녹이 어느 정도 방지될 수 있는 것이다. 그러나 기존의 황금배봉지는 동녹의 정도를 완화시킬 뿐 완전히 방지할 수 없었으며, 봉지를 적 용한 재배조건에서의 동녹발생 기구를 정확히 이해하지 못했었기에 효과적으로 봉지의 기능 을 개선하는 것이 불가능하였다. 과설의 미려도는 과실의 맛과 함께 그 가치를 결정짓는 중요한 물성으로서 우리나라 황 금배 재배환경과 특성에 알맞은 배봉지의 제작이 선결될 때, 배 품질의 향상, 안정된 공급이 가능하게 될 것이며 아울러 농가의 수업증대와 수출 경쟁력 강화가 이루어질 수 있을 것으로 판단된다. 이러한 측면에서 황금배 재배농가가 당면한 동녹발생의 문제점을 신속한 해결 을

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.4
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• pp.60-70
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• 2000

An 8$\times$8+20-bit MAC is designed with low power design methodologies at each of the system design levels. At algorithm level, a new method for multipl $y_tract operation is proposed, and it saves the transistor counts over conventional methods in hardware realization. A new Booth selector circuit using NMOS pass-transistor logic is also proposed at circuit level. It is superior to other circuits designed by CMOS in power-delay-product. And at architecture level, we adopted an ELM adder that is known to be the most efficient in power consumption, operating frequency, area and design regularity as the final adder. For registers, dynamic CMOS single-edge triggered flip-flops are used because they need less transistors per bit. To increase the operating frequency 2-stage pipeline architecture is adopted, and fast 4：2 compressors are applied in Wallace tree block. As a simulation result, the designed MAC in 0.6${\mu}{\textrm}{m}$ 1-poly 3-metal CMOS process is operated at 200MHz, 3.3V and consumed 35㎽ of power in multiply operation, and operated at 100MHz consuming 29㎽ in MAC operations, respectively.ly.