• 대한물리치료과학회지
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• 제31권1호
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• pp.70-87
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• 2024

Background: This study aimed to investigate the effect of Y-balance exercise on spatio-temporal gait parameters in subjects with chronic ankle instability. Design: Randomized Controlled Trial. Method: A study was conducted on 43 people with chronic ankle instability. Subjects performed modified Y-balance exercise 3 times a week for 50 minutes, 4 weeks. Gait parameters were measured using a gait analysis treadmill before exercise, 2 weeks after exercise, and 4 weeks after exercise. A gait analysis treadmill (FDM-T AP1171, Zebris, Germany) was used to measure gait parameters. Mean values were compared using Repeated measured two-way ANOVA. Result:: When comparing the results of three measurements taken before exercise, 2 weeks after exercise, and 4 weeks after exercise, there were significant differences in the qualitative and quantitative aspects of gait in gait variables such as step distance, step time, step ratio, and sway ratio. Conclusions: These results suggest that the Y-balance exercise and various exercises combining balance and proprioception are effective for subjects with chronic ankle instability.

• 한국기계가공학회지
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• 제20권8호
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• pp.93-98
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• 2021

The complex effects of the machining parameters make it is difficult to control and predict surface roughness. The theoretical surface roughness observed during mechanical machining with a round tool is determined by the tool radius and pitch. However, it was revealed that other parameters, such as the depth of cut and cutting speed, also affect surface roughness. This study adapted the Taguchi method, which can analyze the effects of cutting parameters quantitatively with an efficient number of experiments, to optimize the parameters for better surface roughness. Experiments were designed based on an orthogonal array, and the quantitative effects on the surface roughness were analyzed using the S/N ratio. The surface roughness was affected by all parameters, especially the tool radius. The optimum cutting parameter values obtained in this study showed better surface roughness than the other combinations of the parameters.

• 응용통계연구
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• 제31권1호
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• pp.123-137
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• 2018

비선형 혼합효과 모형은 다양한 분야에서 반복 측정 자료를 분석할 때 주로 사용된다. 비선형 혼합효과 모형은 개체 내 변동(intra-individual variation)에 대해 고려하는 제 1단계 개별수준모델(individual-level model)과 개체간 변동(inter-individual variation)에 대해 고려하는 제 2단계 개체군모델(population model)의 두 단계로 구성되어 있다. 비선형 혼합효과 모형의 첫 번째 단계인 개별수준모델은 비선형 회귀모형의 모수를 추정하는 것으로 일반적인 비선형 회귀모형과 같고, 주로 보통최소제곱추정 방법을 사용하여 모수를 추정한다. 그러나 최소제곱추정방법은 가정된 비선형 함수가 자료에 의해 명시적으로 드러나지 않는 경우 모수의 추정값과 그 표준오차가 극단적으로 커지는 문제가 발생할 수 있다. 본 논문에서는 최근에 비선형 회귀모형에서 제안된 능형회귀(ridge regression) 방법을 비선형 혼합효과 모형의 제 1단계 개별수준모델에 도입함으로써 이러한 문제를 해결할 수 있는 새로운 추정방법을 제안하였다. 제안된 추정량은 모의실험 연구를 통하여 기존의 표준적인 추정량과 그 성능을 비교하였다. 또한 미국의 National Toxicology Program으로부터 얻어진 정량적 대량고속 스크리닝(quantitative high throughput screening) 실제 자료를 사용하여 추정 방법들을 비교하였다.

• 대한후두음성언어의학회지
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• 제28권2호
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• pp.89-95
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• 2017

Background and Objectives : High-speed videolaryngoscopy (HSV) is the only technique that captures the true intra-cycle vibratory behavior of the vocal folds by capturing full images of the vocal folds. However, it has problems of no immediate feedback during examination, considerable waiting time for digital kymography (DKG), recording duration limited to a few seconds, and extreme demands for storage space. Herein, we demonstrate a new post-processing method that converts HSV images to two-dimensional digital kymography (2D-DKG) images, which adopts the algorithm of 2D videokymography (2D VKG). Materials and Methods : HSV system was used to capture images of vocal folds. HSV images were post-processed in Kay image-process software (KIPS), and conventional DKG images were retrieved. Custom-made post-processing system was used to convert HSV images to 2D-DKG images. The quantitative parameters of the post-processed 2D-DKG images was validated by comparing these parameters with those of the DKG images. Results : Serial HSV images for all phases of vocal fold vibratory movement are included. The images were converted by the scanning method using U-medical image-process software. Similar to conventional DKG, post-processed 2D DKG image from the HSV image can provide quantitative information on vocal fold mucosa vibration, including the various vibratory phases. Differences in amplitude symmetry index, phase symmetry index, open quotient, and close quotient between 2D-DKG and DKG were analyzed. There were no statistical differences between the quantitative parameters of vocal fold vibratory movement in 2D-DKG and DKG. Conclusion : The post-processing method of converting HSV images to 2D DKG images could provide clinical information and storage economy.

• Korean Journal of Radiology
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• 제22권4호
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• pp.502-512
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• 2021

Objective: To objectively and subjectively assess and compare the characteristics of monoenergetic images [MEI (+)] and polyenergetic images (PEI) acquired by dual-energy CT (DECT) of patients with breast cancer. Materials and Methods: This retrospective study evaluated the images and data of 42 patients with breast cancer who had undergone dual-phase contrast-enhanced DECT from June to September 2019. One standard PEI, five MEI (+) in 10-kiloelectron volt (keV) intervals (range, 40-80 keV), iodine density (ID) maps, iodine overlay images, and Z effective (Z_eff) maps were reconstructed. The contrast-to-noise ratio (CNR) and the signal-to-noise ratio (SNR) were calculated. Multiple quantitative parameters of the malignant breast lesions were compared between the arterial and the venous phase images. Two readers independently assessed lesion conspicuity and performed a morphology analysis. Results: Low keV MEI (+) at 40-50 keV showed increased CNR and SNR_{breast lesion} compared with PEI, especially in the venous phase ([CNR: 40 keV, 20.10; 50 keV, 14.45; vs. PEI, 7.27; p < 0.001], [SNR_{breast lesion}: 40 keV, 21.01; 50 keV, 16.28; vs. PEI, 10.77; p < 0.001]). Multiple quantitative DECT parameters of malignant breast lesions were higher in the venous phase images than in the arterial phase images (p < 0.001). MEI (+) at 40 keV, ID, and Z_eff reconstructions yielded the highest Likert scores for lesion conspicuity. The conspicuity of the mass margin and the visual enhancement were significantly better in 40-keV MEI (+) than in the PEI (p = 0.022, p = 0.033, respectively). Conclusion: Compared with PEI, MEI (+) reconstructions at low keV in the venous phase acquired by DECT improved the objective and subjective assessment of lesion conspicuity in patients with malignant breast lesions. MEI (+) reconstruction acquired by DECT may be helpful for the preoperative evaluation of breast cancer.

• Korean Journal of Radiology
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• 제22권2호
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• pp.233-242
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• 2021

Objective: To evaluate the association of MRI features with the major genomic profiles and prognosis of World Health Organization grade III (G3) gliomas compared with those of glioblastomas (GBMs). Materials and Methods: We enrolled 76 G3 glioma and 155 GBM patients with pathologically confirmed disease who had pretreatment brain MRI and major genetic information of tumors. Qualitative and quantitative imaging features, including volumetrics and histogram parameters, such as normalized cerebral blood volume (nCBV), cerebral blood flow (nCBF), and apparent diffusion coefficient (nADC) were evaluated. The G3 gliomas were divided into three groups for the analysis: with this isocitrate dehydrogenase (IDH)-mutation, IDH mutation and a chromosome arm 1p/19q-codeleted (IDHmut1p/19qdel), IDH mutation, 1p/19q-nondeleted (IDHmut1p/19qnondel), and IDH wildtype (IDHwt). A prediction model for the genetic profiles of G3 gliomas was developed and validated on a separate cohort. Both the quantitative and qualitative imaging parameters and progression-free survival (PFS) of G3 gliomas were compared and survival analysis was performed. Moreover, the imaging parameters and PFS between IDHwt G3 gliomas and GBMs were compared. Results: IDHmut G3 gliomas showed a larger volume (p = 0.017), lower nCBF (p = 0.048), and higher nADC (p = 0.007) than IDHwt. Between the IDHmut tumors, IDHmut1p/19qdel G3 gliomas had higher nCBV (p = 0.024) and lower nADC (p = 0.002) than IDHmut1p/19qnondel G3 gliomas. Moreover, IDHmut1p/19qdel tumors had the best prognosis and IDHwt tumors had the worst prognosis among G3 gliomas (p < 0.001). PFS was significantly associated with the 95th percentile values of nCBV and nCBF in G3 gliomas. There was no significant difference in neither PFS nor imaging features between IDHwt G3 gliomas and IDHwt GBMs. Conclusion: We found significant differences in MRI features, including volumetrics, CBV, and ADC, in G3 gliomas, according to IDH mutation and 1p/19q codeletion status, which can be utilized for the prediction of genomic profiles and the prognosis of G3 glioma patients. The MRI signatures and prognosis of IDHwt G3 gliomas tend to follow those of IDHwt GBMs.

• Investigative Magnetic Resonance Imaging
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• 제17권2호
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• pp.73-82
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• 2013

목적: 수술전 관상내피암으로 진단된 환자에서 침윤성 유방암을 예측하는 정량적 파라미터를 알아보고자 한다. 대상과 방법: 2009년 1월부터 2010년 3월까지, 조직생검상 관상피내암으로 진단된 41명 환자의 42 자기공명영상을 분석하였다. 정량적 파라미터로는 초기조영증강정도, 최대조영증강 정도, 초기에 빠르면서 최대 조영증강을 보인 시점, 조영증강정도, 동맥기 조영증강비율, 겉보기확산계수, 병변의 지름과 용적을 분석하였다. 정량적 파라미터와 침윤성과 연관관계를 알기 위해 일변량 분석과 다변량 분석을 시행하였다. 결과: 42개의 병변중 23 병변이 침윤성 유방암, 19 병변이 관상피내암으로 확진되었다. 병변의 지름 (p=0.003; $6.5{\pm}3.2$ cm vs. $3.6{\pm}2.6$ cm, respectively)과 조영증강비율 (p=0.036; $1.1{\pm}0.3$ vs. $0.9{\pm}0.3$, respectively)가 통계학적으로 의미있게 침윤성 유방암에서 높게 나왔다. 그외 초기에 빠르면서 최대 조영증강을 보인 시점, 동맥기 조영증강비율, 겉보기 확산계수, 병변의 용적은 침윤성 유방암을 예측하는데 통계학적 의미는 없었다. 결론: 분석한 여러가지 정량적 파라미터 중 병변의 지름과 조영증강비율이 수술전 관상피내암으로 진단된 환자에서 침윤성 유방암을 예측하는데 도움이 된다.

• Korean Journal of Radiology
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• 제24권10호
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• pp.1017-1027
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• 2023

Objective: The assessment of cortical integrity following renal injuries with planar Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy depends on measuring relatively decreased cortical uptake (i.e., split renal function [SRF]). We analyzed the additive values of the volumetric and quantitative analyses of the residual cortical integrity using single-photon emission computed tomography (SPECT) compared to the planar scintigraphy. Materials and Methods: This prospective study included 47 patients (male:female, 32:15; age, 47 ± 22 years) who had non-operatively managed renal injuries and underwent DMSA planar and SPECT imaging 3-6 months after the index injury. In addition to planar SRF, SPECT SRF, cortical volume, and absolute cortical uptake were measured for the injured kidney and both kidneys together. The correlations of planar SRF with SPECT SRF and those of SRF with volumetric/quantitative parameters obtained with SPECT were analyzed. The association of SPECT parameters with renal function, grades of renal injuries, and the risk of renal failure was also analyzed. Results: SPECT SRF was significantly lower than planar SRF, with particularly higher biases in severe renal injuries. Planar and SPECT SRF (dichotomized with a cutoff of 45%) showed 19%-36% of discrepancies with volumetric and quantitative DMSA indices (when dichotomized as either high or low). Absolute cortical uptake of the injured kidney best correlated with glomerular filtration rate (GFR) at follow-up (ρ = 0.687, P < 0.001) with significant stepwise decreases by GFR strata (90 and 60 mL/min/1.73 m²). Total renal cortical uptake was significantly lower in patients with moderate-to-high risk of renal failure than those with low risk. However, SRF did not reflect GFR decrease below 60 mL/min/1.73 m² or the risk of renal failure, regardless of planar or SPECT (count- or volume-based SRF) imaging. Conclusion: Quantitative measurements of renal cortical integrity assessed with DMSA SPECT can provide more clinically relevant and comprehensive information than planar imaging or SRF alone.

• 한국약용작물학회지
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• 제25권6호
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• pp.381-388
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• 2017

Background: This study was conducted to acquire basic information on the phenotypic and genotypic characteristics of the germplasm of Panax ginseng C. A. Meyer collected from China and Korea, and identify the variations that can be utilized in ginseng breeding programs. Methods and Results: Quantitative parameters were evaluated, and used to compare and analyze on genetic polymorphisms in the germplasm. The genetic characteristics and classifications were compared and analyzed for each character. Stem length followed a normal frequency distribution ranging from 15.5 cm to 40.5 cm, with showing approximately 40% having a stem length of 20 - 30 mm. Stem diameters ranged from 2.7 mm to 11.3 mm. Stem number per plant ranged from 1 to 3; approximately 50% had a single stem, and 45% had two stems. A non-normal frequency distribution was observed for petiole number, with approximately 60% of the germplasm having 3 - 5 petioles. Petiole length exhibited a normal frequency distribution, raging from 4.5 to 10.6. Petiole angle in the germplasm ranged from $28^{\circ}$ to $89^{\circ}$ and seedstalk length ranged from 5.6 cm to 27.3 cm. Conclusions: The genetic polymorphisms identified by complete linkage clustering based on the quantitative characteristics of Panax ginseng C. A. Meyer collected from Korea and China were classified to 6 groups, namely I, II, III, IV, V, and VI with frequencies of 6.7%, 20.0%, 31.7%, 8.3%, 6.7%, and 26.7%, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제22권3호
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• pp.388-395
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• 2009

The current study was conducted to investigate the effect of early feed restriction (FR, 8 to 14 d of age) on growth performance and immune function in broiler chickens. Birds were fed corresponding diets from 3 to 35 d of age, which consisted of three phases: starter (3 to 7 d of age), FR (8 to 14 d of age) and re-alimentation (15 to 35 d of age) phases. During the FR period, each group of birds was fed the basal diet ad libitum (CON), 85% (EN85) and 70% (EN70) of lower calorie diet ad libitum (qualitative FR), and 85% (FI85) and 70% (FI70) of voluntary intake on a daily basis (quantitative FR). As a result, there was no statistical difference in weight gain, feed intake and feed conversion ratio between the CON and quantitative or qualitative FR groups during the entire (3 to 35 d) periods. In particular, the EN85 group resulted in a significant (p<0.05) increase in weight gain compared with the EN70, FI85 and FI70 groups. Plasma total protein and albumin at 14 d of age (during FR) were significantly (p<0.05) lower in the quantitative and qualitative FR groups, but these parameters at 35 d of age (after re-alimentation) were higher (p<0.05) in the EN85 and EN70 groups than in the CON group. Plasma IgG level was unaffected by dietary FR procedure. In cytokines, there was no significant difference in the expression of lymphocytic IL-4 and IFN-${\gamma}$ at 14 d of age between the FR and the CON groups, whereas lymphocytic IL-6 and iNOS expression were significantly (p<0.05) lower in FI85 and FI70 groups. Moreover, lymphocytic iNOS was also significantly (p<0.05) lower in birds fed qualitative and quantitative diets compared with those fed ad libitum. In the thymus, IL-4 expression was higher (p<0.05) in FI85 and FI70 groups, whereas IL-6 expression was lower (p<0.05) in the FI85 and FI70 groups than in the CON group. Thymic iNOS was significantly (p<0.05) lower in birds fed qualitatively and quantitatively restricted diets compared with those fed ad libitum. At 35 d of age, there was no difference in the expression of IL-4, IL-6 and IFN-${\gamma}$ of lymphocytes and thymus between the FR and CON groups. In conclusion, 85% of quantitative and qualitative FR would have a beneficial effect on the expression of some cytokines including IL-4 and iNOS without change in growth performance of birds.