• 한국세라믹학회지
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• 제25권3호
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• pp.225-230
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• 1988

$Y_2O_3$가 $thickapprox$1mol.% 고용된 정방정 지르코니아를 알루미나에 20vol.% 섞어 체조립에 의해 과립으로 만든 다음 여기에 알루미나에 단사정 지르코니아를 10 ~30 vol.%섞어 만든 과립을 15~30vol.%가 되도록 과립형태로 분산시켜 성형 및 소결함으로써 단사정 및 정방정 지르코니아의 분산영역이 서로 다른 불균질 조직의 $Al_2O_3-ZrO_2$복합체를 제조하여 강도 및 열충격 거동을 관찰하였다. 이러한 불균질 조직의 $Al_2O_3-ZrO_2$ 복합체는 분산 agglomerate 내의 낮은 소결밀도에 의한 기공의 존재, 단사정상에 의한 미세균열, 또 이에 따른 주위에의 압축응력 등이 복합적으로 작용하여 향상된 열충격 거동을 보여 주었다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4739-4742
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• 2013

Carboplatin, a second generation platinum drug, is widely used to treat different types of cancers. However, myelosuppression remains a major consideration in its use. Genetic polymorphisms of enzymes involved in drug disposition can influence therapeutic outcome. The homozygous null deletion of phase II metabolic gene GSTT1 that abolishes its xenobiotic- detoxifying ability may be associated with carboplatin toxicity. Further, since carboplatin generates oxidative stress, polymorphisms of oxidative stress genes that regulate the cellular level of free radicals may have important roles in generating drug- related adverse effects. We here investigated the null polymorphism of GSTT1, and the -463G>A promoter polymorphism of oxidative stress gene myeloperoxidase (MPO) for carboplatin toxicity in a population of northern India. Cancer patients who were treated with carboplatin, and developed toxicity was considered. The study group comprised of 10 patients who developed therapy- related adverse effects. Peripheral blood was taken from patients for DNA isolation. GSTT1 null genotype was determined by conducting duplex PCR and MPO-463 G>A was determined by PCR followed by RFLP. Hematologic toxicity was experienced by 5 patients, 2 of them had grade 3 and 4 toxicity and 3 others had grade 2 toxicity. They also had gastrointestinal (GI) toxicity. Remaining 5 individuals developed GI toxicity but no hematological toxicity. While GG homozygous of MPO was present in majority of patients having hematologic toxicity (in 4 out of 5 individuals), one A allele (AG genotype) was present in 4 patients who did not have any hematological toxicity. Thus variant A allele of MPO -463G>A may be related to lower hematological toxicity. These preliminary data, however, are required to be confirmed in larger studies along with other relevant polymorphisms.

• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.5019-5022
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• 2012

Objective: To evaluate the predictive value of GST gene polymorphisms with regard to prognosis of breast cancer patients receiving neoadjuvant chemotherapy. Methods: A total of 159 patients were included in our study between January 2005 and January 2007. All the patients were followed up until January 2012. Genotyping was based upon the duplex polymerase-chain-reaction with the PCR-CTPP method. Results: Patients with null GSTM1 and GSTP1 Val/Val genotypes had significantly had better response rates to chemotherapy when compared with non-null GSTM1 and GSTP1 Ile/Ile genotypes (OR=1.96 and OR=2.14, respectively). Patients with the GSTM1 null genotype had a longer average survival time and significantly lower risk of death than did those with non-null genotypes (HR=0.66). Similarly, those carrying the GSTP1 Val/Val genotype had 0.54-fold the risk of death of those with GSTP1 Ile/Ile (HR=0.54). Conclusion: A significant association was found between GSTM1 and GSTP1 gene polymorphisms and clinical outcomes in breast cancer cases.

• 한국수산과학회지
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• 제53권5호
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• pp.752-760
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• 2020

Acute hepatopancreatic necrosis disease (AHPND), previously known as early mortality syndrome (EMS), is an emerging disease in shrimp caused by Vibrio parahaemolyticus. Some V. parahaemolyticus strains are associated with foodborne diseases in humans. To date, studies on the relationship between AHPND and pathogenic V. parahaemolyticus are very limited. In this study, we monitored the thermostable direct hemolysin-related hemolysin (trh) gene and AHPND-related genes, such as Photorhabdus insect-related (pir) genes, in 892 strains of V. parahaemolyticus isolated and identified in 24 areas of the West Coast of Korea from May to October 2019. The trh gene was detected in 9.6% of the isolates from short neck clam samples. However, the pirA and pirB genes related to AHPND were not found in any of the isolates despite using both duplex and nested PCR assays, suggesting that AHPND-related genes were nonexistent in the V. parahaemolyticus strains isolated. This study contributes to the current understanding of the relationship between AHPND and V. parahaemolyticus in Korea, as well as provides data on spatial and seasonal distributions of V. parahaemolyticus.

• 한국주조공학회지
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• 제21권1호
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• pp.7-14
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• 2001

The research on new DRA(discontinuous reinforced alloy) and CRA(continous reinforced alloy) composites has been carried out to improve the properties of ceramic fiber and particle reinforced metal matrix composites(MMCs). Effects of alloying elements and aging conditions on the microstructures and aging behavior of Al-Si-Cu-Mg-(Ni)-SiCp composite have been examined. The specimens used in this study were manufactured by duplex process. The first squeeze casting is the process to make precomposite and the second squeeze casting is the process to make final composite. The hardening behavior was accelerated with decreasing the size of SiCp particle in the composites. It is considered that the dislocation density increased with increasing SiCp size, due to the different thermal deformation between Al matrix and SiCp during quenching after the solution treatment. Peak aging time to obtain the maximum hardness in 3 ${\mu}m$ SiCp reinforced Al composite was reduced than that in large size(5, 10 ${\mu}m$) of SiCp because of difference in dislocation density. Aging hardening responce(${\Delta}H$ = $H_{Max}.-H_{S.T}$) of composites was greater than that of unreinforced Al alloy because of higher density of second phases in matrix.

• 한국통신학회논문지
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• 제32권10A호
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• pp.1050-1056
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• 2007

모든 공사 현장에서 철골 세우기 작업시 철골 보, 기둥(H 빔) 등의 이동을 위하여 크레인에 샤클을 부착하여 사용하고 있다. 이때 사용되는 샤클의 해체 작업은 높은 곳으로 올라가 수동으로 해야 하므로 안전사고의 위험성이 높고, 작업의 효율성이 떨어지며, 이는 시공비의 증가로 이어진다. 본 연구에서는 건설현장에서 실용적으로 사용할 수 있는 양방향 RE 통신을 이용한 초소형, 초경량, 저전력, 저가의 오토 샤클을 설계 구현하였으며, 기존 오토 샤클과는 다른 새로운 동작원리와 구조를 채택함으로서 우수한 원격 모니터링, 제어 기능을 갖출 수 있었다. 연구 결과는 여러가지 건설 장비의 원격 제어용으로 응용이 가능하며, 건설장비의 첨단화를 가속화 시킬 것으로 판단된다.

• 동력기계공학회지
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• 제19권6호
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• pp.75-81
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• 2015

A deposited metal specimen of ER2594 which is a super duplex steel welding wire used to investigate the effect of sigma(${\sigma}$) phase on electrochemical corrosion characteristics was prepared by gas tungsten arc welding. Aging treatment was conducted for the specimen at the temperature range of $700^{\circ}C$ to $900^{\circ}C$ for 5 to 300 minutes after annealing at $1050^{\circ}C$. Corrosion current density has decreased a little with an increase of aging time over 60 minutes at $700^{\circ}C$ to $900^{\circ}C$ and the uniform corrosion of deposited metal had more influence on the precipitation of ferrite than the precipitation of sigma phase. Therefore, the precipitation of sigma phase did not have much effect on the uniform corrosion. Pitting potential representing pitting corrosion has shown decreasing tendency as the precipitation of sigma phase increased. The degree of sensitization representing intergranular corrosion has shown increasing tendency as the precipitation of sigma phase increased at $700^{\circ}C$ to $800^{\circ}C$, while it has decreased at $900^{\circ}C$ for 60 to 300 minutes.

• 터널과지하공간
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• 제26권1호
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• pp.32-45
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• 2016

전 세계적으로 도심지 공간의 효율적인 활용을 위한 지하 공간 이용방안에 대해 연구가 진행되어 왔고 미국, 유럽, 중국 등이 복층터널을 건설하여 운영 중이다. 대표적으로, 프랑스의 A86 East, 말레이시아 SMART 터널, 스페인 M30 프로젝트, 미국 시애틀 SR99, 중국 상하이 양쯔강 터널 등을 예로 들 수 있다. 이에 따라서 국내에서도 교통집중을 해소하고 지상 공간 확보를 위해 대심도에 위치하는 네트워크형 복층도로터널 운영에 대한 연구가 진행되고 있다. 그러므로 본 연구에서는 기존에 사용하고 있는 일반적인 도로터널의 환기설계 아웃라인의 리뷰를 통해 대심도 복층터널에 추가적으로 필요한 다양한 요소들을 분석해보고, 해외 복층 도로터널설계사례들을 자세히 검토하여 환기방식과 종류에 따른 환기설계인자분석을 통해 네트워크형 복층 도로터널에 적용 가능한 설계인자를 도출해내고 특징적인 환기설계인자를 새롭게 정립해 본다.

• 한국통신학회논문지
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• 제29권7A호
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• pp.756-765
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• 2004

단일 주파수를 사용하는 무선인식 시스템에서 일대 다수의 통신은 데이터 충돌로 인한 손실이 발생 할 수 있기 때문에 반드시 데이터 충돌을 방지해야만 한다. 기존의 데이터 충돌 방지 방법은 트리검색과 알로하기법을 사용하고 있으나, 인식영역을 통과하는 공간과 시간에 매우 의존적이어서 데이터 손실을 유발할 수 있는 단점이 있다. 그래서 완전 명령 코드 기법을 제안하였다. 완전 명령 코드 기법은 반이중 방식에 적합한 방법으로 태그가 인식 영역에 접근하는 시간을 고려하여 2개 이상의 태그가 리더로 데이터를 송신하지 않는 시간을 계산하여 충돌을 방지하였다. 본 논문에서는 13.56MHz대역의 무선인식 시스템을 제작하여 완전 명령 코드 기법을 적용하여 실험한 결과 완전 명령 코드 기법이 다른 기법에 비해 향상됨을 검증하였으며, O-표기법에 의한 시간 복잡성으로 분석하여 O(n)의 결과를 얻을 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권11호
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• pp.5343-5364
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• 2016

Considering the tradeoff between energy consumption and outage behavior in buffer-aided relay selection, a novel energy-efficient buffer-aided optimal relay selection scheme with power adaptation and Inter-Relay Interference (IRI) cancellation is proposed. In the proposed scheme, energy consumption minimization is the objective with the consideration of relay buffer state, outage probability and relay power control, in order to eliminate IRI. The proposed scheme selects a pair of optimal relays from multiple candidate relays, denoted as optimal receive relay and optimal transmit relay respectively. Source-relay and relay-destination communications can be performed within a time-slot, which performs as Full-Duplex (FD) relaying. Markov chain model is applied to analyze the evolution of relay buffer states. System steady state outage probability and achievable diversity order are derived respectively. In addition, packet transmission delay and power reduction performance are investigated with a specific analysis. Numerical results show that the proposed scheme outperforms other relay selection schemes in terms of outage behavior with power adaptation and IRI cancellation in the same relay number and buffer size scenario. Compared with Buffer State relay selection method, the proposed scheme reduces transmission delay significantly with the same amount of relays. Average transmit power reduction can be implemented to relays with the increasing of relay number and buffer size, which realizes the tradeoff between energy-efficiency, outage behavior and delay performance in green cooperative communications.