• 한국해양공학회지
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• 제32권6호
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• pp.466-473
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• 2018

This paper presents an estimation method for the static configuration of a steel lazy wave riser (SLWR) using the dynamic relaxation method applied to estimate the configuration of structures with strong geometric non-linearity. The lumped mass model is introduced to reflect the flexible structural characteristics of the riser. In the lumped mass model, the tensions, shear forces, buoyancy, self-weights, and seabed reaction forces at nodal points are considered in order to find the static configuration of the SLWR. The dynamic relaxation method using a viscous damping formulation is applied to the static configuration analysis. Fictitious masses are defined at nodal points using the sum of the largest direct stiffness values of nodal points to ensure the numerical stability. Various case studies were performed according to the bending stiffness and size of the buoyancy module using the dynamic relaxation method. OrcaFlex was employed to validate the accuracy of the developed numerical method.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.16-16
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• 2019

The Cassava (Manihot esculenta Crantz) is a perennial woody shrub cultivated mainly in the tropics for its starchy tuberous roots. It belongs to the family Euphorbiaceae which also includes rubber (Hevea brasiliensis) and castor bean (Ricinus communis). Among tropical crops, rice, sugarcane, maize and cassava are the most important sources of calories for human consumption. Problems in the propagation of cassava are virus diseases and low rates of seed germination. Thus, a study was undertaken to develop an efficient in vitro mass propagation protocol of Manihot esculenta Crantz. Young and actively growing stem segments were excised from adult plants of cassava. Samples were cut into a 3~4 cm nodal segments with single node after sterilization, and cultivated in the different medium supplemented with various plant growth regulators for 4 weeks. For shoot multiplication, single-node stem segments, approximately 1 cm in length, were taken from in vitro derived shoots and subcultured. After 4~6 weeks, the shoot generation rate was 55.6%, the shoot number and its length were 1.0/explant and 2.3 cm in the most favorable medium composition. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

• International Journal of Industrial Entomology and Biomaterials
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• 제44권2호
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• pp.55-64
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• 2022

Bombyx shini Park & Sohn, 2002 (Lepidoptera: Bombycidae), which was listed as an endemic species in South Korea has recently been renamed as the East Asian silk moth Rotunda rotundapex Miyata & Kishida, 1990 (Lepidoptera: Bombycidae). In this study, we sequenced the complete mitochondrial genome (mitogenome) of the R. rotundapex to announce genomic characteristics and to clarify its validity with a new name. The 15,294-bp long complete mitogenome comprises a typical set of genes [13 protein-coding genes (PCGs), 2 rRNA genes, and 22 tRNA genes] and one major noncoding, A + T-rich region, with an arrangement identical to that observed in most lepidopteran mitogenomes. The A/T content of the whole mitogenome was 79.22%; however, it varied among the regions/genes as follows: A + T-rich region, 91.62%; srRNA, 84.67%; lrRNA, 83.01%; tRNAs, 81.43%; and PCGs, 77.46%. Phylogenetic analyses of 35 species in the Bombycoidea superfamily showed the sister relationship between the families Sphingidae and Bombycidae s. str., with the higher nodal support [bootstrap support (BS) = 78%]. The Saturniidae was placed as the sister to the two families, but the nodal support for this relationship was low (BS = 53%). Current R. rotundapex was placed together with previously reported con-species with the highest nodal support, forming a separate clade from Bombyx, validating that B. shini can have a new genus name, Rotunda. However, the Korean R. rotundapex showed a substantial sequence divergence at 5.28% to that originated from an individual of type locality Taiwan in 1,459-bp of COI sequences. Considering such a high sequence divergence an additional study, which includes morphological and DNA barcoding data from further extensive distributional range maybe is needed for further robust taxonomic conclusion.

• 대한두경부종양학회지
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• 제38권1호
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• pp.17-24
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• 2022

Background/Objectives: This study analyzed the prognostic significance of clinico-pathologic factors including comprehensive nodal factors in parotid gland cancers (PGCs) patients and constructed a survival prediction model for PGCs patients using machine learning techniques. Materials & Methods: A total of 131 PGCs patients were enrolled in the study. Results: There were 19 cases (14.5%) of lymph nodes (LNs) at the lower neck level and 43 cases (32.8%) involved multiple level LNs metastases. There were 2 cases (1.5%) of metastases to the contralateral LNs. Intraparotid LNs metastasis was observed in 6 cases (4.6%) and extranodal extension (ENE) findings were observed in 35 cases (26.7%). Lymphovascular invasion (LVI) and perineural invasion findings were observed in 42 cases (32.1%) and 49 cases (37.4%), respectively. Machine learning prediction models were constructed using clinico-pathologic factors including comprehensive nodal factors and Decision Tree and Stacking model showed the highest accuracy at 74% and 70% for predicting patient's survival. Conclusion: Lower level LNs metastasis and LNR have important prognostic significance for predicting disease recurrence and survival in PGCs patients. These two factors were used as important features for constructing machine learning prediction model. Our machine learning model could predict PGCs patient's survival with a considerable level of accuracy.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2230-2245
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• 2023

KANT (KAIST Advanced Nuclear Tachygraphy) is a PWR core simulator recently developed at Korea Advance Institute of Science and Technology, which solves three-dimensional steady-state and transient multigroup neutron diffusion equations under Cartesian geometries alongside the incorporation of thermal-hydraulics feedback effect for multi-physics calculation. It utilizes the standard Nodal Expansion Method (NEM) accelerated with various Coarse Mesh Finite Difference (CMFD) methods for neutronics calculation. For thermal-hydraulics (TH) calculation, a single-phase flow model and a one-dimensional cylindrical fuel rod heat conduction model are employed. The time-dependent neutronics and TH calculations are numerically solved through an implicit Euler scheme, where a detailed coupling strategy is presented in this paper alongside a description of nodal equivalence, macroscopic depletion, and pin power reconstruction. For validation of the steady, transient, and depletion calculation with pin power reconstruction capacity of KANT, solutions for various benchmark problems are presented. The IAEA 3-D PWR and 4-group KOEBERG problems were considered for the steady-state reactor benchmark problem. For transient calculations, LMW (Lagenbuch, Maurer and Werner) LWR and NEACRP 3-D PWR benchmarks were solved, where the latter problem includes thermal-hydraulics feedback. For macroscopic depletion with pin power reconstruction, a small PWR problem modified with KAIST benchmark model was solved. For validation of the multi-physics analysis capability of KANT concerning large-sized PWRs, the BEAVRS Cycle1 benchmark has been considered. It was found that KANT solutions are accurate and consistent compared to other published works.

• 대한토목학회논문집
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• 제32권4B호
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• pp.243-251
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• 2012

국립해양조사원의 해운대 부이로 부터 관측된 자료와 CCTV 영상자료를 분석하고 수치실험을 수행하여 해운대 해변에서 발생하는 이안류의 특성을 연구하였다. CCTV 영상자료를 분석한 결과로 부터 이안류가 발생할 때 규칙파에 가깝고 진행방향이 약간 다른 파랑이 중첩되어 입사되고 있는 것을 관찰할 수 있었으며, 부이 관측자료의 웨이브릿 분석으로부터 한 주기에 파랑에너지가 집중된 협대역 스펙트럼을 확인할 수 있었다. 이로부터 이미 알려진 이안류 발생 메커니즘가운데 하나인 벌집구조의 절점선 영역을 통한 이안류의 발생이 해운대 이안류의 주요한 발생 메커니즘임을 추론할 수 있었다. 이러한 이안류 발생 메커니즘은 다음과 같이 설명할 수 있다. 진행방향이 약간 다른 규칙파가 해안으로 전파될 때 서로 중첩되어 비선형 상호작용으로 파봉선이 벌집구조 형상으로 변형된다. 여기서, 파고가 영(zero)인 절점선이 해안선에서 외해방향으로 발달하게 된다. 파고가 상대적으로 작은 이 절점선 영역을 향하여 연안류의 질량수송이 집중되며 일시에 외해로 이안류를 발생시키게 된다. 벌집구조 파봉형상 입사파에 의한 이안류 발생을 재현하기 위해 완전 비선형 Boussinesq 방정식 모형을 이용해 수치모의를 수행하였다. 이 수치모의로부터 진행방향이 서로 다르므로, 그리고 일방향 파랑이 수중천퇴에 의하여 변형되므로 발생된 벌집구조 현상에 의하여 이안류가 잘 발생함을 확인하였다.

• 원예과학기술지
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• 제19권4호
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• pp.483-487
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• 2001

토마토 묘(苗)를 한마디씩 4-6마디로 절단하여 절간을 이용한 마디 삽목 시 삽수의 절위와 소엽의 부착유무가 묘소질에 미치는 영향을 검토하기 위하여 본 시험을 수행하였다. 방울토마토 뻬뻬와 꼬꼬 품종을 플러그 묘를 소엽 1엽을 부착하여 삽목한 처리구가 소엽을 모두 제거한 처리보다 초장과 엽수가 많았고, 지상부중 및 지하부중이 약 3-15배 정도 증가되었다. 토마토 마디삽목묘의 발근율은 하배축이 86%였으나 평균 96%의 높은 발근율을 보였다. 토마토 플러그 묘(苗) 1주(株)로부터 4-6개의 삽수가 얻어졌고 삽목 후 20-24일에 정식 가능한 묘가 생산되었으며, 계속적인 증식이 가능하였다. 토마토 삽목묘의 뿌리는 실생묘에 비하여 직근이 적고 뿌리의 수가 많았다. 그리고 실생묘는 뿌리가 하배축의 끝에서 발근되었으나 마디삽목묘는 상토와 접촉된 모든 부위에서 발생되었다. 육묘방법에 따른 소엽의 변화는 실생묘는 자엽으로부터 마디가 생장점으로 이동함에 따라서 약 1엽, 2엽, 3.5엽 5.5엽으로 엽수가 증가되고, 측지삽목묘는 11.3, 11.9, 13.2, 13.3엽으로 첫째 마디부터 엽수가 현저하게 많았다. 한편 마디삽목묘의 엽수는 약 3.5, 3.6, 4.4엽 및 5.8엽으로 증가되어 측지삽목묘보다는 현저하게 적었으나, 실생묘보다는 많았다. 같은 마디삽목묘의 소엽수(小葉數)도 삽수마디가 하배축에서 생장점으로 이동함에 따라서 소엽수(小葉數)가 크게 증가되었다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.459-462
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• 2012

Expression of estrogen-receptor (ER), progesterone-receptor (PR) and HER-2 has recently been linked with various breast cancer subtypes identified by gene microarray. This study aimed to document breast cancer subtypes based on ER, PR and HER-2 status in Thai women, where expression of these subtypes may not be similar to those evident in Western women. During 2009 to 2010, histological findings from 324 invasive ductal carcinomas (IDC) at Siriraj Hospital were studied. Various subtypes of IDC were identified according to expression of ER, PR and HER-2: luminal-A (ER+;PR+/-;HER-2-), luminal-B (ER+;PR+/-;HER-2 +), HER-2 (ER-;PR- ;HER-2+) and basal-like (ER-;PR-;HER-2-). As well, associations of tumor size, tumor grade, nodal status, angiolymphatic invasion (ALI), multicentricity and multifocality with different breast cancer subtypes were studied. Of 324 IDCs, 143 (44.1%), 147 (45.4%), 15 (4.6%) and 12 (3.7%) were T1, T2, T3 and T4, respectively. Most tumors were grade 2 (54.9%) and had no nodal involvement (53.4%). According to ER, PR and HER-2 status, 192 (59.3%), 40 (12.3%), 43 (13.3%) and 49 (15.1%) tumors were luminal-A, luminal-B, HER-2 and basal-like subtypes. HER-2 subtype presented with large tumor (p=0.04, ANOVA). Luminal-A IDC was associated with single foci (p<0.01, ${\chi}^2$). HER-2 and basal-like subtypes were likely to have high tumor grade (p<0.01, ${\chi}^2$). In addition, HER-2 subtype had higher number of nodal involvement (p=0.048, ${\chi}^2$). In conclusion, the luminal-A subtype accounted for the majority of IDCs in Thai women. Percentages of HER-2 and basal-like IDCs were high, compared with a recent study from the USA. The HER-2 subtype was related with high nodal invasion. The findings may highlight biological differences between IDCs occurring in Asian and Western women.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.147-155
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• 2012

Aboriginal and Torres Strait Islander people comprise about 2.5% of the Australian population. Cancer registry data indicate that their breast cancer survivals are lower than for other women but the completeness and accuracy of Indigenous descriptors on registries are uncertain. We followed women receiving mammography screening in BreastScreen to determine differences in screening experiences and survivals from breast cancer by Aboriginal and Torres Strait Islander status, as recorded by BreastScreen. This status is self-reported and used in BreastScreen accreditation, and is considered to be more accurate. The study included breast cancers diagnosed during the period of screening and after leaving the screening program. Design: Least square regression models were used to compare screening experiences and outcomes adjusted for age, geographic remoteness, socio-economic disadvantage, screening period and round during 1996-2005. Survival of breast cancer patients from all causes and from breast cancer specifically was compared for the 1991-2006 diagnostic period using linked cancer-registry data. Cox proportional hazards regression was used to adjust for socio-demographic differences, screening period, and where available, tumour size, nodal status and proximity of diagnosis to time of screen. Results: After adjustment for socio-demographic differences and screening period, Aboriginal and Torres Strait Islander women participated less frequently than other women in screening and re-screening although this difference appeared to be diminishing; were less likely to attend post-screening assessment within the recommended 28 days if recalled for assessment; had an elevated ductal carcinoma in situ but not invasive cancer detection rate; had larger breast cancers; and were more likely than other women to be treated by mastectomy than complete local excision. Linked cancer registry data indicated that five-year year survivals of breast cancer cases from all causes of death were 81% for Aboriginal and Torres Strait Islander women, compared with 90% for other women, and that the former had larger breast cancers that were more likely to have nodal spread at diagnosis. After adjusting for socio-demographic factors, tumour size, nodal spread and time from last screen to diagnosis, Aboriginal and Torres Strait Islander women had approximately twice the risk of death from breast cancer as other women. Conclusions: Aboriginal and Torres Strait Islander women have less favourable screening experiences and those diagnosed with breast cancer (either during the screening period or after leaving the screening program) have lower survivals that persist after adjustment for socio-demographic differences, tumour size and nodal status.

• 대한기계학회논문집A
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• 제41권1호
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• pp.31-40
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• 2017

1990년대 중반에 개발된 절대절점좌표는 탄성체 동역학 해석에 활용되고 있다. 운동방정식을 유도하는 과정에서 변위장을 이루는 다항식의 차수가 증가하면 필연적으로 자유도가 증가하게 되고, 이는 해석 시간의 증가로 이어진다. 따라서 본 연구에서는 차원 운동방정식을 무차원 운동방정식으로 전환함으로써 해석 시간을 단축시키고자 하였다. 위치 벡터를 이루는 형상 함수는 무차원으로, 절점 좌표는 길이 차원으로 정리한 후 무차원화하는 변수를 통해 무차원 질량행렬, 무차원 선형 강성행렬 및 무차원 보존력을 유도하였다. 무차원 운동방정식의 검증과 효율성은 정적 처짐에 대한 정해가 존재하는 외팔보 및 단진자 예제를 통해 제시하였다.