• Safety and Health at Work
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• 제8권1호
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• pp.36-41
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• 2017

Background: Police work is generally sedentary although there may be situations that require physical endurance and strength, such as foot chases and arresting suspects. Factors such as excessive body fat can impede an officer's physical ability to deal with such occurrences. Our objective was to examine associations between officers' body fat percentage (BF%) and performance on a standardized fitness protocol. Methods: Data were obtained from fitness screening among 1,826 male and 115 female officers in a large US police agency. The screening consisted of a 2.4-km run, push-ups, sit-ups, and sit-and-reach test. Sex-specific body fat percentages were estimated from skinfold thickness measured using calipers. Linear regression models were used to examine unadjusted and adjusted mean scores of fitness tests across BF% tertiles. Results: The prevalence of overall fitness was 4.3 times greater in male officers and 3.6 times greater in female officers having the lowest BF% tertile compared with the highest tertile (30.3% vs 7.1% and 46.0% vs 12.8%, respectively). BF% was linearly and positively associated with the time of 2.4-km run (p < 0.001), and linearly and inversely associated with the number of push-ups (p < 0.001), sit-ups (p < 0.001), and the distance of sit-and-reach (p < 0.001) in men. Similar associations were observed in women with the exception of sit-and-reach (p = 0.122). Associations were independent of age, race/ethnicity, rank, and duty station. Conclusion: Overall, BF% was inversely associated with fitness levels in male and female officers. Future longitudinal studies should be initiated to explore the potentially causal relationship between BF% and fitness in law enforcement officers.

• Clinical and Experimental Pediatrics
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• 제63권11호
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• pp.438-446
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• 2020

Background: Most developmental screening tools in Korea are adopted from foreign tests. To ensure efficient screening of infants and children in Korea, a nationwide screening tool with high reliability and validity is needed. Purpose: This study aimed to independently develop, standardize, and validate the Korean Developmental Screening Test for Infants and Children (K-DST) for screening infants and children for neurodevelopmental disorders in Korea. Methods: The standardization and validation conducted in 2012-2014 of 3,284 subjects (4-71 months of age) resulted in the first edition of the K-DST. The restandardization and revalidation performed in 2015-2016 of 3.06 million attendees of the National Health Screening Program for Infants and Children resulted in the revised K-DST. We analyzed inter-item consistency and test-retest reliability for the reliability analysis. Regarding the validation of K-DST, we examined the construct validity, sensitivity and specificity, receiver operating characteristic curve analysis, and a criterion-related validity analysis. Results: We ultimately selected 8 questions in 6 developmental domains. For most age groups and each domain, internal consistency was 0.73-0.93 and test-retest reliability was 0.77-0.88. The revised K-DST had high discriminatory ability with a sensitivity of 0.833 and specificity of 0.979. The test supported construct validity by distinguishing between normal and neurodevelopmentally delayed groups. The language and cognition domain of the revised K-DST was highly correlated with the K-Bayley Scales of Infant Development-II's Mental Age Quotient (r=0.766, 0.739), while the gross and fine motor domains were highly correlated with Motor Age Quotient (r=0.695, 0.668), respectively. The Verbal Intelligence Quotient of Korean Wechsler Preschool and Primary Scales of Intelligence was highly correlated with the K-DST cognition and language domains (r=0.701, 0.770), as was the performance intelligence quotient with the fine motor domain (r=0.700). Conclusion: The K-DST is reliable and valid, suggesting its good potential as an effective screening tool for infants and children with neurodevelopmental disorders in Korea.

• 지능정보연구
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• 제20권4호
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• pp.121-139
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• 2014

기업의 부도 예측은 재무 및 회계 분야에서 매우 중요한 연구 주제이다. 기업의 부도로 인해 발생하는 비용이 매우 크기 때문에 부도 예측의 정확성은 금융기관으로서는 매우 중요한 일이다. 최근에는 여러 개의 모형을 결합하는 앙상블 모형을 부도 예측에 적용해 보려는 연구가 큰 관심을 끌고 있다. 앙상블 모형은 개별 모형보다 더 좋은 성과를 내기 위해 여러 개의 분류기를 결합하는 것이다. 이와 같은 앙상블 분류기는 분류기의 일반화 성능을 개선하는 데 매우 유용한 것으로 알려져 있다. 본 논문은 부도 예측 모형의 성과 개선에 관한 연구이다. 이를 위해 사례 선택(Instance Selection)을 활용한 배깅(Bagging) 모형을 제안하였다. 사례 선택은 원 데이터에서 가장 대표성 있고 관련성 높은 데이터를 선택하고 예측 모형에 악영향을 줄 수 있는 불필요한 데이터를 제거하는 것으로 이를 통해 예측 성과 개선도 기대할 수 있다. 배깅은 학습데이터에 변화를 줌으로써 기저 분류기들을 다양화시키는 앙상블 기법으로 단순하면서도 성과가 매우 좋은 것으로 알려져 있다. 사례 선택과 배깅은 각각 모형의 성과를 개선시킬 수 있는 잠재력이 있지만 이들 두 기법의 결합에 관한 연구는 아직까지 없는 것이 현실이다. 본 연구에서는 부도 예측 모형의 성과를 개선하기 위해 사례 선택과 배깅을 연결하는 새로운 모형을 제안하였다. 최적의 사례 선택을 위해 유전자 알고리즘이 사용되었으며, 이를 통해 최적의 사례 선택 조합을 찾고 이 결과를 배깅 앙상블 모형에 전달하여 새로운 형태의 배깅 앙상블 모형을 구성하게 된다. 본 연구에서 제안한 새로운 앙상블 모형의 성과를 검증하기 위해 ROC 커브, AUC, 예측정확도 등과 같은 성과지표를 사용해 다양한 모형과 비교 분석해 보았다. 실제 기업데이터를 사용해 실험한 결과 본 논문에서 제안한 새로운 형태의 모형이 가장 좋은 성과를 보임을 알 수 있었다.

• 약학회지
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• 제55권5호
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• pp.411-418
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• 2011

The dissolution test method and an analytical procedure by HPLC were developed and validated for nafronyl oxalate capsules and tramadol hydrochloride capsules. These drugs were not yet characterized by the dissolution specifications in the Korean Pharmaceutical Codex. So, with each reference and test drugs, we did the preliminary and standard experiments based on the Korean Pharmacopeia Guideline of dissolution testing for solid oral dosage forms. The dissolution test for nafronyl oxalate capsules was carried out under sink conditions as follows: dissolution medium phosphate buffer pH 6.8, paddle rotation speed 100 rpm and vessel volume 900 ml. More than 80% of its label amount was released within 30 min in this method. Also the dissolution test for tramadol hydrochloride capsules was carried out under sink conditions as follows: dissolution medium water, paddle rotation speed 50 rpm and vessel volume 900 ml. More than 90% of its label amount was released within 15 min in this method. The dissolution samples were analyzed with a validated HPLC analytical procedure. The analytical methodology showed acceptable values in terms of specificity, linearity, precision and accuracy. The dissolution test methods described above were adequate for the purpose and may be proposed as a pharmacopeial standard to assess the performance of nafronyl oxalate capsules and tramadol hydrochloride capsules. Furthermore, the outcomes of this study were expected to help create an environment where safe and high quality drugs would be distributed on the domestic market making contributions to advancing public health.

• 한국도로학회논문집
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• 제19권6호
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• pp.37-46
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• 2017

PURPOSES : A composite pavement utilizes both an asphalt surface and a concrete base. Typically, a concrete base layer provides structural capacity, while an asphalt surface layer provides smoothness and riding quality. This pavement type can be used in conjunction with rollercompacted concrete (RCC) pavement as a base layer due to its fast construction, economic efficiency, and structural performance. However, the service life and functionality of composite pavement may be reduced due to interfacial bond failure. Therefore, adequate interfacial bonding between the asphalt surface and the concrete base is essential to achieving monolithic behavior. The purpose of this study is to investigate the bond characteristics at the interface between asphalt (HMA; hot-mixed asphalt) and the RCC base. METHODS : This study was performed to determine the optimal type and application rate of tack coat material for RCC-base composite pavement. In addition, the core size effect, temperature condition, and bonding failure shape were analyzed to investigate the bonding characteristics at the interface between the RCC base and HMA surface. To evaluate the bond strength, a pull-off test was performed using different diameters of specimens such as 50 mm and 100 mm. Tack coat materials such as RSC-4 and BD-Coat were applied in amounts of 0.3, 0.5, 0.7, 0.9, and $1.1l/m^2$ to determine the optimal application rate. In order to evaluate the bond strength characteristics with temperature changes, a pull-off test was carried out at -15, 0, 20, and $40^{\circ}C$. In addition, the bond failure shapes were analyzed using an image analysis program after the pull-off tests were completed. RESULTS : The test results indicated that the optimal application rate of RSC-4 and BD-Coat were $0.8l/m^2$, $0.9l/m^2$, respectively. The core size effect was determined to be negligible because the bond strengths were similar in specimens with diameters of 50 mm and 100 mm. The bond strengths of RSC-4 and BD-Coat were found to decrease significantly when the temperature increased. As a result of the bonding failure shape in low-temperature conditions such as -15, 0, and $20^{\circ}C$, it was found that most of the debonding occurred at the interface between the tack coat and RCC surface. On the other hand, the interface between the HMA and tack coat was weaker than that between the tack coat and RCC at a high temperature of $40^{\circ}C$. CONCLUSIONS : This study suggested an optimal application rate of tack coat materials to apply to RCC-base composite pavement. The bond strengths at high temperatures were significantly lower than the required bond (tensile) strength of 0.4 MPa. It was known that the temperature was a critical factor affecting the bond strength at the interface of the RCC-base composite pavement.

• 생물환경조절학회지
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• 제29권4호
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• pp.440-447
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• 2020

최근 간척지를 활용한 대규모 수출 원예 단지에 대한 수요가 증대되고 있고, 대규모 시설원예 단지 조성을 위한 현안 중에 하나는 경량 온실용 기초 설계 기준을 확립하는 것이다. 이를 위해 연약지반 기초 보강 방법에 관한 사전 연구들을 검토하였다. 대상 공법으로는 스파이럴, 나무, 쇄석 다짐 말뚝(팽이) 및 PF 공법이며, 성능 검증을 위해 인발저항력, 지내력, 침하량 측정 등의 시험이 수행되었다. 인발저항력은 동일한 직경에서 근입 깊이가 증가할수록 저항력이 상승하는 것을 확인 할 수 있었다. 스파이럴과 나무 말뚝 기초의 성능을 비교하자면, 유사한 근입비와 마찰 면적을 갖는 기준에 대하여 스파이럴 말뚝의 인발저항력 0.8kN, 나무 말뚝은 인발저항력 1.1kN로 근소하게 나무 말뚝의 성능이 우수하다고 판단되었다. 추가적으로, 일정 근입비(L/D)의 범위에서의 직경 변화에 따른 인발저항력을 비교하였다. 근입비 10~12.1 범위에서는 직경 250mm구간, 근입비 14.6~16.7 범위에서의 직경 300mm구간에서 급격한 상승값을 보였으며, 근입비 범위에 따라 인발저항력 증가 폭이 다르게 나타나는 것을 확인하였다. 지반 지내력 검토를 위한 재하시험 결과의 경우, 상이한 보강 방법, 직경, 관입 깊이 등의 영향으로 단순 비교하는 것에 한계가 있지만, 나무 말뚝 105kN/㎡, 팽이 말뚝 826kN/㎡, PF방법 300kN/㎡ 수준의 최대 허용지지력을 보였다. 위 조건의 경우에, 팽이 말뚝, PF방법, 나무 말뚝 순으로 높은 지내력을 나타냈다. 간척지 기초 시공공법 타당성 검토를 위하여, 일부 국한된 시험 조건하에 인발저항력, 허용지지력, 침하량 측정 등 시험 평가 결과를 비교 검토하였다. 기초 보강 방법 별 일관성있는 경향을 파악하는데 한계가 있었지만, 풍속40m/s에서 온실에서 받는 인발력이 20kN수준이고(Yu 등, 2012), '97 한국형 유리온실 표준설계도에 명시된 온실의 기초 지내력 기준이 50kN/㎡인 점을 고려한다면 지내력 105kN/㎡ ~ 826kN/㎡ 범위의 기초보강 공법인 팽이, 나무말뚝 및 PF방법 모두 간척지 온실 기초에 적용하기 충분한 공법으로 간주 된다. 장기 침하량 모니터링 및 기초 보강 방법 별 수렴성과 재현성이 확보된 실증 데이터 보완을 통해, 온실 유형별 구조안정성과 경제성을 동시에 만족시킬 수 있는 기초 방식 선정과 설계 가이드라인 제시가 가능할 것이라고 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권5호
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• pp.1907-1912
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• 2015

Purpose: The study was designed to: (1) investigate the prevalence of high-risk human papillomavirus (HR-HPV) infection and cervical neoplasia; and (2) evaluate clinical performance of visual inspection with acetic acid/ Lugol's iodine (VIA /VILI), Pap smear, high-risk human papillomavirus (HR-HPV) DNA test for detecting cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and (3) explore appropriate screening approach in rural areas of Shandong Province. Materials and Methods: A total of 3,763 eligible women from Yiyuan County in Yimeng mountainous areas of rural Shandong, China, were enrolled and underwent Pap smear, HR-HPV DNA testing by Hybrid Capture 2 (HC2), and VIA /VILI tests. Women positive in any test were referred to colposcopy and biopsy as indicated. Results: The prevalence of HR-HPV infection among all enrolled women was 11.1% and that in healthy women was 9.9%. In total 33 cases of CIN1, 16 cases of CIN2, 6 cases of CIN3 but none of cervical cancer were detected and the crude prevalence of CIN2+ was 0.58%. For detecting CIN2+, the sensitivity of HR-HPV DNA testing, VIA/VILI, Pap smear was 90.9%, 77.3%, 81.8%, respectively. Pap smear had the best specificity of 98.2%, followed by HR-HPV DNA testing with specificity of 89.4%, VIA/VILI had the lowest specificity of 81.2%. Colposcopy referral rate of HR-HPV DNA testing, VIA/VILI, Pap smear was 11.1%, 18.5%, 2.3%, respectively. Conclusions: Our results suggest that HR-HPV DNA testing alone might be appropriate for primary cervical cancer screening in rural low-resource areas of Shandong Province, China.

• 한국프랜차이즈경영연구
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• 제10권2호
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• pp.49-58
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• 2019

Purpose - As the growth potential of the cultural contents industry steadily grows, the cinemas industry is growing fast especially due to popularity and commerciality. The recent in the cinemas industry is evolving on multiplex cinemas that combine cultural facilities such as theaters, restaurants, and shopping centers. Due to the rapid growth of multiplex cinemas, many researchers have studied the characteristics of visiting customers in Korea. Among them, selection attribute of multiplex cinemas, including the service quality and physical environment, is important because it may examines the cause of customer 's behavior. Thus, this research focuses on the effects of the selection attributes of the multiplex cinemas on customer satisfaction and their loyalty. This research suggests the guidelines for how cinemas should manage their customers and build their customers satisfaction and loyalty that improve business performance. Research design, data, and methodology - This study tests the structural relationship between selection attributes of multiplex cinemas, customer satisfaction, and loyalty. selection attributes of multiplex cinemas divide into five sub-dimensions such as movies facility quality, services, cleanliness, accessibility, and snack bars quality. In order to examine the purposes of this research, research model and hypotheses were developed. All constructs were measured with multiple items developed and tested in the previous studies. The data were collected from 100 students in their 10-20s and were analyzed using SPSS 22.0, SmartPLS 3.0 and fsQCA program. Result - The findings of this research are as follows. First, all selection attributes except cleanliness have significant positive impacts on customer satisfaction and loyalty. Second, customer satisfaction has significant positive impact on loyalty. Third, as a result of fsQCA, high satisfaction and high accessibility were the necessary conditions on loyalty. Fourth, the necessary conditions for male and female groups were different. Conclusions - The implications of this study are as follows. Overall, multiplex cinemas should manage selection attributes basically regardless of the type of theater. Especially, cleanliness was not significant, but the customer probably consider it an essential and basic factors. Also, they are able to manage the selection attributes differently depending on the type of gender. For the male customers, it is effective that centralized strategy and for female customers, it is effective that emphasized the multiplex cinemas image.

• Korean Journal of Radiology
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• 제24권10호
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• pp.1028-1037
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• 2023

Objective: To evaluate the computed tomography (CT) features for diagnosing metastatic cervical lymph nodes (LNs) in patients with differentiated thyroid cancer (DTC) and validate the CT-based risk stratification system suggested by the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) guidelines. Materials and Methods: A total of 463 LNs from 399 patients with DTC who underwent preoperative CT staging and ultrasound-guided fine-needle aspiration were included. The following CT features for each LN were evaluated: absence of hilum, cystic changes, calcification, strong enhancement, and heterogeneous enhancement. Multivariable logistic regression analysis was performed to identify independent CT features associated with metastatic LNs, and their diagnostic performances were evaluated. LNs were classified into probably benign, indeterminate, and suspicious categories according to the K-TIRADS and the modified LN classification proposed in our study. The diagnostic performance of both classification systems was compared using the exact McNemar and Kosinski tests. Results: The absence of hilum (odds ratio [OR], 4.859; 95% confidence interval [CI], 1.593-14.823; P = 0.005), strong enhancement (OR, 28.755; 95% CI, 12.719-65.007; P < 0.001), and cystic changes (OR, 46.157; 95% CI, 5.07-420.234; P = 0.001) were independently associated with metastatic LNs. All LNs showing calcification were diagnosed as metastases. Heterogeneous enhancement did not show a significant independent association with metastatic LNs. Strong enhancement, calcification, and cystic changes showed moderate to high specificity (70.1%-100%) and positive predictive value (PPV) (91.8%-100%). The absence of the hilum showed high sensitivity (97.8%) but low specificity (34.0%). The modified LN classification, which excluded heterogeneous enhancement from the K-TIRADS, demonstrated higher specificity (70.1% vs. 62.9%, P = 0.016) and PPV (92.5% vs. 90.9%, P = 0.011) than the K-TIRADS. Conclusion: Excluding heterogeneous enhancement as a suspicious feature resulted in a higher specificity and PPV for diagnosing metastatic LNs than the K-TIRADS. Our research results may provide a basis for revising the LN classification in future guidelines.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제24권4호
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• pp.220-227
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• 2013

Objectives : This study aims to investigate the clinical characteristics and neuropsychological profiles of children with attention-deficit hyperactivity disorder (ADHD) and their siblings. Methods : Eighteen children (age $8.2{\pm}1.7$ years, 12 boys) with ADHD and their 18 siblings (age $7.8{\pm}1.6$ years, 8 boys) completed Continuous Performance (CPT), Stroop, Children's Trail Making, Rey-Kim Memory, and Kim's Frontal Executive Function tasks. The parents of these subjects underwent the Attention-Deficit/Hyperactivity Disorder Rating Scale (ARS), 10-item Parent General Behavior Inventory (P-GBI), and the Social Responsiveness Scale (SRS). Paired t-tests were used. Results : The inattention (p=.020), and hyperactivity-impulsivity (p=.001), scores of the ARS and the P-GBI score (p=.004) were significantly higher in children with ADHD than in their siblings. Deficits in social communication and motivation on SRS were higher in children with ADHD than in their siblings (p=.017 and p=.011, respectively). Z-scores of omission and commission errors as well as response time variability on visual CPT and omission errors on auditory CPT were in clinically significant range, and z-score of omission errors on auditory CPT was in borderline range in siblings. Omission (p=.018) and commission errors on Visual CPT (p=.007) were significantly higher in children with ADHD compared to their siblings. Recognition efficiency on Kim's Frontal Executive Function Task was lower in children with ADHD compared to their siblings, but in normal range in both groups. Stroop interference and figure fluency on Kims Frontal Executive Function Task were in borderline range in ADHD group, and figure fluency was in borderline range in siblings. Conclusion : Our results support a preliminary evidence for mild degree of attention deficit in ADHD siblings. Further studies are needed to examine the cognitive functions of siblings with ADHD in larger samples.