• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.345-349
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• 2015

Background: To determine the cut-off values of the preoperative risk of malignancy index (RMI) used in differentiating benign or malignant adnexal masses and to determine their significance in differential diagnosis by comparison of different systems. Materials and Methods: 191 operated women were assessed retrospectively. RMI of 1, 2, 3 and 4; cut-off values for an effective benign or malignant differentiation together with sensitivity, specificity, negative and positive predictive values were calculated. Results: Cut-off value for RMI 1 was found to be 250; there was significant (p<0.001) compatibility at this level with sensitivity of 60%, positive predictive value (PPV) of 75%, specificity of 93%, negative predictive value (NPV) of 88% and an overall compliance rate of 85%. When RMI 2 and 3 was obtained with a cut-off value of 200, there was significant (p<0.001) compatibility at this level for RMI 2 with sensitivity of 67%, PPV of 67%, specificity of 89%, NPV of 89%, histopathologic correlation of 84% while RMI 3 had significant (p<0.001) compatibility at the same level with sensitivity of 63%, PPV of 69%, specificity of 91%, NPV of 88% and a histopathologic correlation of 84%. Significant (p<0.001) compatibility for RMI 4 with a sensitivity of 67%, PPV of 73%, specificity of 92%, NPV of 89% and a histopathologic correlation of 86% was obtained at the cut-off level 400. Conclusions: RMI have a significant predictability in differentiating benign and malignant adnexal masses, thus can effectively be used in clinical practice.

• KDI Journal of Economic Policy
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• v.31 no.1
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• pp.207-237
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• 2009

One of the main problems in Korea's public assistance program, the NBLS (National Basic Livelihood Security), is that the loophole of welfare system is continuously growing. Living wage program is the largest sub-program of the NBLS, and the most important determinant of amount of living wage for each beneficiary is the level of reported income. Therefore, accurate and effective income detection is essential in improving policy effects and furthermore reducing the leakage of wage expenditure as beneficiaries always have an incentive to underreport their income. Since most of them do not pay income tax, the welfare authority should exert an independent effort to effectively detect their income. Considering that living wage is a special kind of income tax of which marginal tax rate is -1, one can apply a classical theory of tax evasion to understand illegal or excessive receipt of living wage caused by income underreporting. Utilizing a classical theory given by Alingham and Sandmo (1972), this paper provides a theoretical analysis of the optimal income reporting of the beneficiary. Then an optimization problem is constructed from the government's viewpoint to derive optimal income detecting device (auditing). This paper proves that cut-off discriminated auditing outperforms random auditing and cut-off auditing which implies if the government assigns a positive audit probability to every reported income less than a certain level and the probability is inversely proportional to the level of reported income, it can minimize underreporting and then gradually reduce the leakage of wage expenditure.

• Korean Journal of Optics and Photonics
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• v.3 no.1
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• pp.55-62
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• 1992

The optical absorption characteristics of glasses colored by CdS. CdSe, $CdS_{1-x}Se_x$,ZnS, and ZnSe microcrystallites have been studied with emphasis on changes of the cut-off wavelength. The sharpcut filters with various cut-off wavelengths were fabricated by controlling the composition and the heat-treatment temperature. The cut-off wavelength shifts due to the different heat-treatment temperatures for CdS. CdSe, ZnS, and ZnSe doped SK-16 glasses were found to be relatively small(~30 nm). However, by treating the CdS1,Se, doped SK-16 glasses with different x values at the same heattreatment temperature, it was possible to obtain the filters with various cut-off wavelengths(~130 nm) without losing the high extinction coefficients of the filters. The filter glasses with various cut-off wavelngths(~100 nm) and high extinction coefficiencts were also produced by treating the CdSe and $CdS_{0.5}Se_{0.5}$ doped ZK-1 glasses at different temperatures.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.3
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• pp.202-209
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• 2022

Objective: The aim of this study was to assess the correlation of oocyte number with serum anti-Müllerian hormone (AMH) levels measured by two automated methods (Access or Elecsys) in fresh stimulated in vitro fertilization (IVF) cycles. Methods: In this retrospective study at a university hospital, data were collected from 243 fresh stimulated IVF cycles performed from August 2016 to December 2020. The serum AMH level was measured by Access in 120 cycles and by Elecsys in 123 cycles. The cut-off of serum AMH for prediction of poor responders (three or fewer oocytes) or high responders (15 or more oocytes) was calculated by the receiver operating characteristic curve analysis. Results: For the two automated methods, the following equations were derived: total oocyte number=2.378+1.418×(Access-AMH) (r=0.645, p<0.001) and total oocyte number=2.417+2.163×(Elecsys-AMH) (r=0.686, p<0.001). The following combined equation could be derived: (Access-AMH)=0.028+1.525×(Elecsys-AMH). To predict poor responders, the cut-off of Access-AMH was 1.215 ng/mL (area under the curve [AUC], 0.807; 95% confidence interval [CI], 0.730-0.884; p<0.001), and the cut-off of Elecsys-AMH was 1.095 ng/mL (AUC, 0.848; 95% CI, 0.773-0.923; p<0.001). To predict high responders, the cut-off of Access-AMH was 3.450 ng/mL (AUC, 0.922; 95% CI, 0.862-0.981; p<0.001), and the cut-off of Elecsys-AMH was 2.500 ng/mL (AUC, 0.884; 95% CI, 0.778-0.991; p<0.001). Conclusion: Both automated methods for serum AMH measurement showed a good correlation with oocyte number and good performance for predicting poor and high responders in fresh stimulated IVF cycles. The Access method usually yielded higher measured serum AMH levels than the Elecsys method.

• Clinical and Experimental Pediatrics
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• v.48 no.4
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• pp.387-394
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• 2005

Purpose : We performed this study to compare the TSH and free $T_4$ levels according to gestational age and birth weight, and to reevaluate the cut-off values in the neonatal screening test for congenital hypothyroidism. Methods : Total 2,133 neonates(1,749 healthy newborns and 384 sick neonates) were screened in Dankook University Hospital from May 2000 to January 2003. Neonates with abnormal TSH values (higher than $20{\mu}IU/mL$) or abnormal free $T_4$ levels(lower than 1 ng/dL) were recalled to recheck the thyroid function test. At that time, physical examinations and history-taking regarding perinatal problem, medication history, and mother's illness were undertaken. Results : Serum TSH and free $T_4$ values revealed no significant difference according to sex, delivery type, and Apgar score. The free $T_4$ levels showed statistically significant differences, with gestational age or birth weight(P<0.01). The recall rate of neonates due to abnormal screening test was 7.48 percent. Compared with original cut-off values, the recall rate of the new cut-off values setted to TSH higher than $20{\mu}IU/mL$ or free $T_4$ lower than 0.64 ng/dL decreased from 7.48 percent to 4.8 percent in the healthy group. But, it compromised sensitivity when applied to the sick group. Conclusion : In this study, neonatal free $T_4$ levels were significantly different according to birth weight, gestational age, and the presence of compromised condition. Although the recall rate by TSH > $20{\mu}IU/mL$ or free $T_4$ <1 ng/dL was relatively high, it was impossible to set up new cut-off values without compromising sensitivity. We think studies including a larger study population will be required to change the cut-off values.

• Ocean and Polar Research
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• v.27 no.3
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• pp.277-288
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• 2005

Spatial distribution and vertical structures of water masses around the Antarctic continental margin are described using synthesized hydrographic data. Antarctic Surface Water (AASW) over the shelf regime is distinguished from underlying other water masses by the cut-off salinity, varying from approximately 34.35 to 34.45 around Antarctica. Shelf water, characterized by salinity greater than the cut-off salinity and potential temperature less than $-17^{\circ}C$, is observed on the Ross Sea, off George V Land, off Wilkes Land, the Amery Basin, and the Weddell Sea, but in some shelves AASW occupies the entire shelf. Lower Circumpolar Deep Water is present everywhere around the Antarctic oceanic regime and in some places it mixes with Shelf Water, producing Antarctic Slope Front Water (ASFW). ASFW, characterized by potential temperature less than about $0^{\circ}C$ and greater than $-17^{\circ}C$, and salinity greater than the cut-off salinity, is found everywhere around Antarctica except in the Bellingshausen-Amundsen sector. The presence of different water masses over the Antarctic shelves and shelf edges produces mainly three types of water mass stratifications: no significant meridional property gradient in the Bellingshausen and Amundsen Seas, single property gradient where ASFW presents, and a V-shaped front where Shelf Water exists.

• The Korean Journal of Applied Statistics
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• v.9 no.2
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• pp.161-169
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• 1996

In the design of the sampling, it is important to make a decision about the size of the sample to be selected from the population. We often have a problem to get the optical size of the sample to be considered for cost and time expended for selecting sample unit from highly skewed population. In this case, we give a graphical criterion with Take-all Stratum rate to choose a method and also illustrate the efficiency between the Neyman allocation and the cut-off method with real data.

• ALGAE
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• v.29 no.3
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• pp.183-195
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• 2014

There are recognized three new species of Polysiphonia sensu lato at a 10-20 m water depth from Jeju Island, Korea. We described the morphology of three new species and analyzed rbcL sequences to infer phylogenetic relationships among Polysiphonia sensu lato. Polysiphonia amplacapilli sp. nov. is characterized by an epiphytic, discoid holdfast, 5-7 pericentral cells, large trichoblasts, lateral branches connecting with trichoblasts, only slightly corticated in the basal parts, cut-off rhizoids and a spiral arrangement of tetrasporangia. Polysiphonia morroides sp. nov. is characterized by saxicolous, cut-off rhizoids, four pericentral cells, ecorticate, spiral arrangement of tetrasporangia, and it was collected at the fast-flowing water habitat in 20-25 m depth. Polysiphonia sabulosia sp. nov. is characterized by ecorticate, 5-6 pericentral cells, a single filamentous trichoblast, lateral branches connecting with the trichoblasts, cut-off rhizoids, and spiral arrangement of tetrasporangia, and is growing in the sandy locations. The phylogenetic analysis of rbcL sequences demonstrated that three new species are clearly distinguished from other species of Polysiphonia sensu lato.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.690-692
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• 2003

In this paper, we have investigated characteristics of radio frequency for double gate MOSFET with 50nm main gate in according to variation of side gate length. We could know the increasement of cut-off frequency as the side gate length is lower. As a result, we could know the most optimum performance characteristics when side gate length was 70nm. In this time, the DG MOSFET of side gate with 70nm has very high cut-off frequency like 41.4GHz.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.11
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• pp.76-83
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• 2007

The dark-field laser scattering system has been developed to inspect surface defects in infrared cut-off filters and then laser scattering characteristics against the defects are investigated. The qualitative analysis for the reliable and accurate detection performance is described through the correlation between incident angles of a laser and viewing ones of a camera. In this paper, reliable and important information with laser scattering is given for the surface defect inspection of IR filters. Its performance has been verified through various experiments.