• Journal of Ocean Engineering and Technology
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• v.34 no.1
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• pp.26-36
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• 2020

An extreme value analysis of metocean data which include wave, wind, and current data is a prerequisite for the operation and survival of offshore structures. The purpose of this study was to provide information about the return wave, wind, and current values for the Barents Sea using extreme value analysis. Hindcast datasets of the Global Reanalysis of Ocean Waves 2012 (GROW2012) for a waves, winds and currents were obtained from the Oceanweather Inc. The Gumbel distribution, 2 and 3 parameters Weibull distributions and log-normal distribution were used for the extreme value analysis. The least square method was used to estimate the parameters for the extreme value distribution. The return values, including the significant wave height, spectral peak wave period, wind speed and current speed at surface, were calculated and it will be utilized to design offshore structures to be operated in the Barents Sea.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.2
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• pp.106-110
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• 2017

The developmental responses of insects to temperature are important considerations in gaining a better understanding of their ecology and life histories. Temperature dependent models permit examination of the effect of temperature on the geographical distributions, population dynamics, and management of insects. The measurements of insect developmental and survival responses to temperature pose practical challenges that depend. The developmental characteristics of A. diaperinus were investigated at four temperature regimes (20, 25, 30 and $35^{\circ}C$), a relative humidity of 60%, and a light:dark photoperiod of 16:8h. The developmental time from larva to adult was 129.0, 49.8, 40.5 and 31.9 days at temperatures of 20, 25, 30 and $35^{\circ}C$, respectively. Pupal rate was 80.0%, 100%, 83.3% and 91.7% at temperatures of 20, 25, 30 and 35 respectively. There is an increasing need for a standardized manual for rearing this. Pupa had significantly lower weights at $35^{\circ}C$ than at the other temperatures. Female pupae (20mg) were significantly heavier than male (17mg).

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.389-403
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• 1997

Survey on MIC of antimicrobial drugs and its treatment efficacy in mice were conducted for the strains of Escherichia coli and Salmonella spp isolated from feces of young domestic animals with diarrhea in 1996. A total of 338 strains of E coli and 61 strains of Salmonella spp were examined for the susceptibility to 20 antibiotics and 7 synthetic antimicrobial drugs. The results indicated that the majority of strains were susceptible to amikacin(93.5%), cefoperazone/sulbactam(93.5%), cefotaxim(93.3%), cefomandole(92.8%), cefoperazone(91.6%) and ciprofloxacin(85.1%), in order. Although gentamicin, ciprofloxacin and norfloxacin showed the relatively low MIC distributions, erythromycin, doxycycline, sulfamethoxazole and oxytetracycline revealed the high MIC distributions to most of isolates. The $MIC_{90}$ of antimicrobials for E coli were > $62.5{\mu}g/ml$ in gentamicin, $2.0{\mu}g/ml$ in ciprofloxacin, $1.0{\mu}g/ml$ in norfloxacin, > $500{\mu}g/ml$ in erythromycin, $125{\mu}g/ml$ in doxycycline, > $1000{\mu}g/ml$ in sulfamethoxazole and > $250{\mu}/ml$ in oxytetracycline. In general, the MIC of E coli isolates was higher than that of Salmonella spp isolates. Although variation in synergism or additivity of antibiotic combinations were demonstrated, ampicillin-gentamicin was the most efficacious combination both against E coli and Salmonella spp with the fluctuation of 7.7-77.5%. In the experiment of treatment efficacy in mice, the highest survival ratio(83.3%) after challenge with pathogenic E coli and Salmonella typhimurium was detected in the group treated with gentamicin.

• Journal of the Korean Institute of Landscape Architecture
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• v.36 no.3
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• pp.52-62
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• 2008

By analyzing specific plant distributions and physicochemical characteristics of topsoil in a reclaimed dredging area, baseline data was found of natural landscape planting sites, and developing dredged fill ground. The reclaimed dredging area is five different stands (1, 2, 3, 4 and 5) which were examined in this research. They are located from sea level to 15 meters in altitude and exhibited typical characteristics of the salt marsh in Gwangyang Bay. Species with high constancy in the vegetation on the reclaimed soil were classified into four stages. A total of 12, 15, 22, 27 and 35 different plant species were found and also increased in stands 1, 2, 3, 4 and 5, respectively. Moving from stand 1 to 5, halophytes decreased and non-halophytes increased. Desalination at each stage of the reclaimed dredging area was a driving force affecting the performance and distribution of halophytes and non-halophytes. Overall, 35 quadrats of soil were selected and analyzed for specific physicochemical characteristics of topsoil between O${\sim}$20cm. Results of the physicochemical analysis such as altitude, slope, vegetation and kind of reclaimed dredging soil, exhibited irregular increases or decreases. As survey areas moved from stand 1 to 4, desalination areas, soil acidity, electric conductions, content of salinity, available phosphorus, potassium, chlorine, calcium, and magnesium indicated decreasing patterns; however, total nitrogen, silt, and clay content increased. Cluster analysis and PCA by environmental data within the stands clearly showed five distinct vegetation patterns on the tested reclaimed area. These results indicate that the differences of performance and distribution of vegetation are due to the SAR in the reclaimed soil and related to the natural survival strategy at the given hostile habitat.

• Korean Journal of Bronchoesophagology
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• v.15 no.2
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• pp.49-56
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• 2009

Purpose : To evaluate the treatment outcome for patients with locally advanced, unresectable esophageal cancer treated with relatively high dose radiation therapy(RT). Materials and Methods : From January 2000 to December 2008, 32 patients with locally advanced unresectable or medically inoperable esophageal cancer were treated with radiation therapy(RT) with or without concurrent chemotherapy. Ten patients were excluded from analysis because of distant metastasis and drop off. Patient distributions according to AJCC stages II, III IVa were 7(31.8%), 12(54.6%), 3(13.6%) respectively. The locations of tumor were cervical/upper thorax 3 (13.6%), mid thorax 13(59.1%), and lower thorax/abdominal 6(27.3%), respectively. Eleven patients received RT only, and 11 patients received cisplatin based concurrent chemoradiotherapy(CCRT). Median radiation dose was 65 Gy(range 57.6~72 Gy). Results : The median follow-up was 9.1 months(range 1.9~43.8 months). The response rates for complete response, Partial response, stable disease and Persistent disease were 6(27.3%), 11(50.0%), 4(18.2%) and 1(4.5%), respectively. Two patients(9.1%) suffered from esophageal stenosis and stents were inserted. Two patients(9.1%) had Grade 3 radiation pneumonitis and one of them expired due to acute respiratory distress syndrome(ARDS) at 36 days after completion of radiation therapy. The recurrence rate was 11(50.0%). The patterns of recurrence were persistent disease and local progression in 5(22.7%), local recurrence 3(13.7%) and concomitant local and distant recurrence in 3(13.7%). The overall survival(OS) rate was 32.1% at 2 years and 21.4% at 3 years(median 12.0 months). Disease free survival(DFS) rate was 17.3% at 2 and 3 years. All patients who had no dysphagia at diagnosis showed complete response after treatment and 100% OS at 3 years(p=0.0041). The OS for above 64.8 Gy group and 64.8 Gy or below group at 3 years were 60.6% and 9.1%(p=0.1341). The response to treatment was the only significant factor affecting OS(p=0.004). Conclusion : Relatively high dose radiation therapy in unresectable esophageal cancer tended to have a better outcome without increased complication rate. Further study with more patients is warranted to justify improved result.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.193-204
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• 2010

Purpose: To analyze the treatment outcomes, complications, prognostic factors after a long-term follow-up of patients with nasopharyngeal carcinoma treated with radiation therapy (RT) alone or concurrent chemoradiation therapy (CCRT). Materials and Methods: Between December 1981 and December 2006, 190 eligible patients with non-metastatic nasopharyngeal carcinoma were treated at our department with a curative intent. Of these patients, 103 were treated with RT alone and 87 patients received CCRT. The median age was 49 years (range, 8~78 years). The distributions of clinical stage according to the AJCC 6th edition included I: 7 (3.6%), IIA: 8 (4.2%), IIB: 33 (17.4%), III: 82 (43.2%), IVA: 31 (16.3%), IVB: 29 (15.3%). The accumulated radiation doses to the primary tumor ranged from 66.6~87.0 Gy (median, 72 Gy). Treatment outcomes and prognostic factors were retrospectively analyzed. Acute and late toxicities were assessed using the RTOG criteria. Results: A total of 96.8% (184/190) of patients completed the planned treatment. With a mean follow-up of 73 months (range, 2~278 months; median, 52 months), 93 (48.9%) patients had relapses that were local 44 (23.2%), nodal 13 (6.8%), or distant 49 (25.8%). The 5- and 10-year overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) rates were 55.6% and 44.5%, 54.8% and 51.3%, in addition to 65.3% and 57.4%, respectively. Multivariate analyses revealed that CCRT, age, gender, and stage were significant prognostic factors for OS. The CCRT and gender were independent prognostic factors for both DFS and DSS. There was no grade 4 or 5 acute toxicity, but grade 3 mucositis and hematologic toxicity were present in 42 patients (22.1%) and 18 patients (9.5%), respectively. During follow-up, grade 3 hearing loss in 9 patients and trismus in 6 patients were reported. Conclusion: The results of our study were in accordance with findings of previous studies and we confirmed that CCRT, low stage, female gender, and young age were related to improvement in OS. However, there are limitations in the locoregional control that can be achieved by CCRT with 20 conventional radiation therapy. This observation has led to further studies on clarifying the efficacy of concurrent chemotherapy by intensity modulated radiation therapy.

• The Korean Journal of Applied Statistics
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• v.25 no.2
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• pp.311-319
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• 2012

The simplest and the most important distribution in survival analysis is exponential distribution. Koziol and Green (1976) derived Cram$\acute{e}$r-von Mises statistic's randomly censored version based on the Kaplan-Meier product limit estimate of the distribution function; however, it could not be practical for a real data set since the statistic is for testing a simple goodness of fit hypothesis. We generalized it to the composite hypothesis for exponentiality with an unknown scale parameter. We also considered the classical Kolmogorov-Smirnov statistic and generalized it by the exact same way. The two statistics are compared through a simulation study. As a result, we can see that the generalized Koziol-Green statistic has better power in most of the alternative distributions considered.

• International Journal of Reliability and Applications
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• v.7 no.1
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• pp.27-39
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• 2006

Many real world cases in material failure analysis do not follow perfectly the normal distribution. Forcing of the normality assumption may lead to inaccurate predictions and poor product quality. We examine the failure process of the internal bond (IB or tensile strength) of medium density fiberboard (MDF). We propose a forced censoring technique that closer fits the lower tails of strength distributions and better estimates extremely smaller percentiles, which may be valuable to continuous quality improvement initiatives. Further analyses are performed to build an accelerated common-shaped Weibull model for different product types using the $JMP^{(R)}$ Survival and Reliability platform. In this paper, a forced censoring technique is implemented for the first time as a software module, using $JMP^{(R)}$ Scripting Language (JSL) to expedite data processing, which is crucial for real-time manufacturing settings. Also, we use JSL to automate the task of fitting an accelerated Weibull model and testing model homogeneity in the shape parameter. Finally, a package script is written to readily provide field engineers customized reporting for model visualization, parameter estimation, and percentile forecasting. Our approach may be more accurate for product conformance evaluation, plus help reduce the cost of destructive testing and data management due to reduced frequency of testing. It may also be valuable for preventing field failure and improved product safety even when destructive testing is not reduced by yielding higher precision intervals at the same confidence level.

• Journal of the Korean Geotechnical Society
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• v.16 no.4
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• pp.201-208
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• 2000

Axial load distribution in model piles was measured by fiber Bragg Grating(FBG) sensor to investigate a possibility of analyzing the load transfer mechanism by Fiber Optic sensor system. Since FBGs of different wave lengths can be multiplexed in an optical fiber, the installation of sensor system and the measurement of strains are relatively simple, compared with consisting strain gages. In this study, FBG sensors and electric strain gages were embedded in the same piles and the distributions of load transfer by two sensor systems were measured. It was observed from the test results that the variations of axial load by both systems showed insignificant difference and that the measurements by FBG were smoother than those by strain gage. Under the environments of laboratory testing, survival rate of embedded FBG system was higher than that of strain gage. Therefore, it was concluded that the use of FBG sensor has a great potential for the measurement of load transfer for pile foundation.

• Journal of Ecology and Environment
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• v.41 no.8
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• pp.223-234
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• 2017

Background: Spatial structure of plants in a population reflects complex interactions of ecological and evolutionary processes. For dioecious plants, differences in reproduction cost between sexes and sizes might affect their spatial distribution. Abiotic heterogeneity may also affect adaptation activities, and result in a unique spatial structure of the population. Thus, we examined sex- and size-related spatial distributions of old-growth forest of dioecious tree Torreya nucifera in extremely heterogeneous Gotjawal terrain of Jeju Island, South Korea. Methods: We generated a database of location, sex, and size (DBH) of T. nucifera trees for each quadrat ($160{\times}300m$) in each of the three sites previously defined (quadrat A, B, C in Site I, II, and III, respectively). T. nucifera trees were categorized into eight groups based on sex (males vs. females), size (small vs. large trees), and sex by size (small vs. large males, and small vs. large females) for spatial point pattern analysis. Univariate and bivariate spatial analyses were conducted. Results: Univariate spatial analysis showed that spatial patterns of T. nucifera trees differed among the three quadrats. In quadrat A, individual trees showed random distribution at all scales regardless of sex and size groups. When assessing univariate patterns for sex by size groups in quadrat B, small males and small females were distributed randomly at all scales whereas large males and large females were clumped. All groups in quadrat C were clustered at short distances but the pattern changed as distance was increased. Bivariate spatial analyses testing the association between sex and size groups showed that spatial segregation occurred only in quadrat C. Males and females were spatially independent at all scales. However, after controlling for size, males and females were spatially separated. Conclusions: Diverse spatial patterns of T. nucifera trees across the three sites within the Torreya Forest imply that adaptive explanations are not sufficient for understanding spatial structure in this old-growth forest. If so, the role of Gotjawal terrain in terms of creating extremely diverse microhabitats and subsequently stochastic processes of survival and mortality of trees, both of which ultimately determine spatial patterns, needs to be further examined.