The Characteristics of Korean Mutual Savings Banks and Cost Efficiency

In the local economy, mutual savings banks play an important role. Nowadays, their roles are enhanced in the banking industry. But researches about mutual savings banks are very deficient. This paper focuses that the characteristics of Korean mutual savings banks bear some relation to the cost efficiency. This study estimates the cost efficiency of Korean mutual saving banks for the period 2002∼2007 by using a mathematical programming approach called DEA, and analyzes the characteristics of Korean mutual savings bankings on this efficiency. The outcome of this study was shown as follows. First, the results show that about 18∼21% of total operating costs could have been saved if all savings banks had been cost efficient during the period. Second, the largest asset sized group shows higher cost efficiency scores than the other asset sized groups. It is that the asset size is important on the mutual savings bankings management. Third, our result suggests that mutual savings banks with small-size branch networks are more efficient than big or mid-size branch networks. But be careful to analyze branch network. Because almost mutual savings banks have 1 or 2 branches. Forth, the higher ownership concentration on the mutual savings banking is more efficient but, it has a no relation with cost efficiency by a regression analysis. Fifth, the listed mutual savings banks are more efficient than the others. The listed must disclose their information so, people trust their management. Sixth, the stability and the credit loans health are very important factors to increase their cost efficiency. Last, the results of tobit regression are statistically significant at the 5% levels except ownership concentration.;상호저축은행은 서민과 지역을 기반으로 하는 소규모 기업의 금융편의를 도모하고 저축을 활성화시키기 위해 설립된 금융기관으로 국내 금융경제에서 그 역할과 영향력이 점점 커지고 있다. 하지만 상호저축은행의 커지는 역량과 이들의 역할이 지역경제와 밀접한 관련을 가지고 있음에도 불구하고 상호저축은행에 대한 관심과 연구는 많이 부족한 실정이다. 따라서 상호저축은행의 올바른 성장과 발전을 위서는 이에 대한 심도 있고 다양한 연구가 매우 필요한 상황이다. 따라서 본 연구는 이러한 필요성을 충족시키고 상호저축은행의 발전방향을 모색하는데 있어서 도움이 되고자 시작되었다. 본 연구는 상호저축은행의 비용효율성을 기관이나 조직의 효율성을 측정하는데 쓰이는 비모수적 접근방법인 DEA(Data Envelopment Analysis)라는 수학적 프로그래밍 기법을 이용하여 측정하고 이렇게 측정된 비용효율성과 상호저축은행의 여러 가지 특성과의 관계를 살펴보았다. 연구의 데이터는 상호저축은행의 감사보고서를 기초로 하고 있으며 2003년부터 가장 최근인 2007년까지의 기간을 대상으로 하였다. 상호저축은행의 특성을 선택함에 있어서는 선행연구들을 참고하여 금융산업의 운영과 영업실적에 관련하여 영향력이 있는 것으로 판명된 자산의 규모, 지점수, 주식시장의 상장여부, 대주주의 주식소유 비중, BIS자기자본비율, 고정이하여신비율을 선정하였다. 연구의 결과를 살펴보면 2003년부터 2007년까지의 분석기간 동안 산업 전반적으로 비용효율성에 있어서 18∼21% 정도의 비효율성이 있었음을 확인 할 수 있다. 각 특성별로 살펴보면 저축은행의 자산규모가 클수록 비용효율성이 증가하며 자산규모가 상호저축은행의 비용효율성에 영향력이 상당히 있는 것으로 나타났다. 하지만 저축은행의 지점수는 많은 것보다 오히려 적을수록 효율적인 것으로 나타났다. 하지만 대부분의 저축은행의 지점이 1∼2개인 것을 감안하여 볼 필요가 있을 것이다. 또한 주식시장에 상장되어 있는 8개의 저축은행이 그렇지 않은 은행들보다 효율성이 더 높은 것으로 나타났으며 대주주의 주식소유비중이 클수록 상호저축은행의 경영에 있어서 효율성이 높은 것으로 나타났다. 그리고 저축은행의 자본적정성과 여신건전성을 나타내주는 BIS자기자본비율, 고정이하여신비율의 경우 자본적정성이 높고 여신건전성이 좋을수록 비용효율성의 측정치가 높은 것을 확인할 수 있었다. 마지막으로 이러한 특성들을 Tobit모형을 이용하여 회귀분석을 해본 결과 대주주의 주식 비중을 제외한 특성들이 5% 유의수준에서 비용효율성과의 관계가 유의하게 나타났다. 이는 이러한 특성들이 저축은행의 비용효율성에 상당한 영향력을 가진다는 의미로 앞으로 상호저축은행의 효율성 개선을 위해 고려해야할 점에 대한 제안이 되어 줄 수 있으리라 생각된다.제Ⅰ장 서론 = 1 1.1 연구 동기 및 목적 = 1 1.2 논문의 구성 = 3 제Ⅱ장 선행연구 고찰 = 4 2.1 해외 선행연구 = 4 2.2 국내 선행연구 = 5 제Ⅲ장 상호저축은행의 현황분석 = 7 제Ⅳ장 이론적 배경 및 연구모형 = 13 4.1 이론적 배경 = 13 4.1.1 효율성의 개념과 측정 방법 = 13 4.1.2 효율성 측정을 위한 방법과 기존연구 = 16 4.1.3 DEA(Data Envelopment Analysis) 모형 = 20 4.2 연구모형 = 26 제Ⅴ장 실증분석 = 28 5.1 산출물 및 투입물 = 28 5.2 변수의 선정 = 29 5.3 실증분석 = 31 5.3.1 분석 대상 요약 = 31 5.3.2 효율성 측정 결과 = 32 5.3.3 효율성과 관련된 연구가설 = 33 5.3.4 회귀분석결과 = 37 제Ⅵ장 결론 = 41 참고문헌 = 43 부록 = 46 ABSTRACT = 5

Mammographic Density Estimation: Comparison Between Radiologist’s Visual Assessment and Volpara Breast Density

Purpose : To retrospectively compare Volpara mammographic density estimation with the density by radiologists based on the Breast Imaging Reporting and Data System (BI-RADS) density classification. Materials and Methods : Materials and methods: From twentieth December 2011 to twenty fourth December 2011, 116 patients aged 25-74 years who had mammography with Volpara density grade were included in this study. We reviewed the patient’s breast density grade of BI-RADS categories by radiologists and Volpara. Weighted kappa statistic was used in measuring agreement between radiologists and Volpara imaging software. Mann Whitney test was used for comparison total breast volume (mL), fibroglandular tissue volume (mL), and degree of breast density (%) in group with technical error of Volpara imaging software and group without error. Results : Overall agreement of breast density between the radiologist’s BI-RADS and Volpara imaging software was moderate (k=0.428). Five (4.3%) patients had technical error of Volpara imaging software in breast density measurements. Statistical analysis showed a significant difference in total breast tissue volume (mL) and degree of breast density (%) when comparing group with technical error of Volpara software and group without technical error of that method (p=0.0301, p=0.0067). Conclusion : The agreement of radiologists and Volpara imaging software was moderate (kappa value = 0.428). Small total breast volume (mL) and high degree of breast density (%) were causes of the Volpara softwear error.ope

Thyroid nodules ≤ 5 mm on ultrasonography: are they "leave me alone" lesions?

The incidence of small thyroid malignancy has increased. However, there is no evidence-based guideline for managing thyroid nodules ≤ 5 mm on ultrasonography (US). We evaluated how to manage thyroid nodules ≤ 5 mm. Thyroid nodules ≤ 5 mm in size on US that had undergone surgery and US-guided fine-needle aspiration were eligible. A total of 3,117 thyroid nodules in 3,012 patients were included. The size changes of malignant and benign nodules during follow-up were evaluated. Thyroid malignancies were classified according to follow-up and surgery time within and after 12 months. Clinico-pathological characteristics were compared. Of 3,117 nodules, 1,639 nodules in 1,619 patients were benign and 1,478 in 1,427 were malignant. Only 5.8 and 1.2 % of malignant nodules and 6.8 and 4.2 % of benign nodules increased in size when a 2-mm and 3-mm change on US were referenced. Of 1,079 patients with an index malignancy ≤ 5 mm, extrathyroidal extension, lymph node metastasis, recurrence, and mortality were not significantly different between patients with and without follow-up and between patients with surgery within 12 months and after 12 months. None of the patients who underwent surgery had distant metastasis and none died of thyroid malignancy. In thyroid nodules ≤ 5 mm found on US, US-FNA could be recommended in cases of increased size during US follow-up if lateral LNM was not found because a delay in surgery did not impact cancer recurrence and mortality.ope

Positive Predictive Value of BI-RADS US Category 4 and 5 Lesions

Purpose: To retrospectively analyze the positive predictive values (PPVs) of the lesions classified as categories 4 and 5 by using Breast Imaging Reporting and Data System (BI-RADS) ultrasonography (US). Materials and Methods: Between January 2012 and April 2012, the 558 lesion of 494 patients were reported BI-RADS US category 4 and 5. We reviewed the frequency, pathologic or clinical course. The PPVs for category 4a, 4b, 4c and 5 were evaluated. Results: Among the 558 lesions, the 395 lesions were pathologically confirmed as benign lesions and the 148 lesions were pathologically confirmed as malignant lesions. The 15 lesions were not pathologically confirmed. Among them, the 11 lesions were failed to follow up and 4 lesions are reassessed as category 3 lesions at the time of biopsy, which was scheduled to follow up rather than biopsy. The PPV for category 4 was 15.1% and the PPVs for subcategory 4a, 4b and 4c 5 were 7.8%, 60.0% and 78.1%. And the PPV for category 5 was 98.7%. Conclusion: In our hospital, the PPVs for BI-RADS US category 4a, 4b, 4c and 5 were presented to show the range of BI-RADS US, so it was appropriately subcategorized.ope

Needle Localization of Breast in Referral Center

Purpose: To retrospectively analyze the recent trend of the needle localization of the breast in reference hospital. Materials and Methods: Between March 2010 and June 2012, the 1966 breast lesions of 1286 patients were localized using hook wired needle for surgery. We retrospectively reviewed the type, numbers of the lesion of each patient, reason of the localization, and surgical methods. Results: A total of 1966 localizations were performed during this period. A hook wire was inserted by the radiologist, guided by ultrasonography (1684 cases) or stereotactic X - ray guidance (282 cases). The cause of needle localization was categorized as breast cancer (922 cases), satellite lesion in breast cancer patient (486 cases), benign or high risk lesion (476 cases), and microcalcifications which are only seen in mammography (82 cases). The number of lesion in each patient was divided as 1 lesion (759 cases), 2 lesions (439 cases), 3 lesions (95 cases) and more than 4 lesions ( 11 cases). Conclusion: The numbers of diagnostic needle localization has decreased due to core needle biopsy and stereotactic biopsy. Relatively, needle localization of nonpalpable breast cancer has much more increased.ope