• 아태비즈니스연구
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• 제15권1호
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• pp.99-111
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• 2024

Purpose - This study aims to quantify the long tail effect in the digital economy. It also investigates the role of digital platform before and after the COVID-19 pandemic. Design/methodology/approach - We take advantage of a granular data set from one of the biggest digital platforms in Korea. Rather than computing the absolute number of products sold or the Gini coefficient, we estimate the slope of the log-linear relationship of the non-parametric sales distribution. Findings - We find that the use of online food order and delivery services is positively associated with individual restaurant's sales growth. We also document that the long tail effect is increasing over time. Long tail effects are clustered in the cross-section where average revenue per order is high or the restaurant belongs to the top 50% of the sales distribution. Research implications or Originality - The findings may indicate that digital platforms are contributing to the development of the digital economy in Korea. Also, we confirm that digital platforms make it possible for small and sole proprietors to go through the difficulties induced by the COVID-19 pandemic.

• Journal of Preventive Medicine and Public Health
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• 제26권4호
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• pp.661-671
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• 1993

In order to compare the geographical distribution of physician by level of medical care and specialty, a log linear model was applied to the annual registration data of the Korean Medical Association as of the end of December, 1991 which was supplemented from related institutions and adjusted with relevant sources. Those physicians in primary and secondary care institutions were not statistically significantly unevenly distributed by province-level catchment area. There were some differences in physician distribution among big cities, medium and small-sized cities, and counties; however, those physicians for primary care level were equitably distributed between cities and counties. Specialties for secondary care physicians were less evenly distributed in county areas than in city areas, and generalists are distributed more evenly in cities and counties than in big cities. There is a certain limitation due to underregistration in the annual physician registration to the Korean Medical Association; however, the geographical distribution of physicians has been improved quantitatively. It is strongly suggested that specialties and the level of medical care should be considered for further physician manpower studies.

• 한국토양비료학회지
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• 제17권4호
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• pp.343-348
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• 1984

제주도(濟州道)와 울릉도(鬱陵島)에 분포(分布)한 용암류(熔岩類) 대지토양(台地土壤)의 이화학성(理化學性)을 분류단위수준(分類單位水準)(목일대군일통(目一大群一統))에서 작도단위(作圖單位)에 대(對)한 토양단면내(土壤斷面內) 토양특성(土壤特性)의 변이성(變異性) 및 순수성(純粹性)을 분석(分析)한 결과(結果)는 다음과 같다. (1) 일반적(一般的)으로 토양관리(土壤管理)에 의(依)해 영향(影響)을 많이 받는 화학성(化學性)은 물리성(物理性)보다 변이성(變異性)이 컸음. (2) 토양관리(土壤管理) 방법(方法)에 따른 변이성(變異性)은 분류단위(分類單位)가 낮아짐에 따라 감소(減少)하였음. (3) 토양통(土壤統) 설정시(設定時) 순수성(純粹性)은 목(目), 대군(大群) 및 통(統)에서 각각(各各) 66.5, 56.0 및 43.8%이었음. (4) 모래함량(含量)과 몇가지 화학성(化學性)은 대수정규(對數正規) 분포(分布)를 하므로 이들의 평균(平均)을 수정(修正)하였음.

• 한국정보과학회논문지:데이타베이스
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• 제27권4호
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• pp.549-561
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• 2000

데이터베이스 관리 시스템(DBMS)에서의 부분 철회는 수행 중인 트랜잭션 전체를 철회하지 않고 일부분만을 철회할 수 있는 유용한 기능으로 많은 관계형 DBMS(RDBMS)에서 지원되고 있다. 그러나, RDBMS와는 달리 객체지향 DBMS(OODBMS)에서는 객체 버퍼와 페이지 버퍼로 구성되는 이중의 버퍼구조를 유지하므로 페이지 버퍼만을 유지하는 RDBMS에서 사용하던 기존의 부분 철회 방식을 그대로 이용할 수 없다. 따라서, 이러한 이중 버퍼 내의 데이터를 효과적으로 부분 철회할 수 있는 새로운 회복 방법이 필요하다. 본 논문에서는 이중 버퍼구조를 사용하는 OODBMS를 위한 네가지 부분 철회 방식들을 제안한다. 제안된 부분 철회 방식들은 부분 철회의 주요 대상인 버퍼의 구조에 따라 단일 버퍼 기반 부분 철회, 소프트 로그를 이용한 이중 버퍼 기반 부분 철회, 그리고 섀도우를 이용한 이중 버퍼기반 부분 철회 방식으로 세분화한다. 수학적 분석 및 실험을 통한 성능 평가에 의하면 이중 버퍼 기반 부분 철회 방식의 성능이 가장 우수한 것으로 나타났다.

• 정보관리학회지
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• 제27권1호
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• pp.25-40
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• 2010

본 연구는 사회 네트워크 분석 기법을 통하여 K대학도서관의 학술DB 이용현황을 분석하고 이용자의 요구에 적합한 서비스를 개발 및 제공하고자 하는데 그 목적을 두고 있다. 이를 위하여 K대학 도서관의 학술DB 로그 데이터를 이용하여 학문분야별, 신분별, 학문분야 및 신분별 학술DB 네트워크를 구성하고 실증 분석하였다. 본 연구의 결과, 전임교원의 학술DB 네트워크와 박사과정의 학술DB 네트워크는 특화된 학술DB를 중심으로 강한 결속력을 보이고 있으며 다른 신분의 학술DB 네트워크보다 밀도, 연결정도 집중도 및 연결정도 중심성이 높게 나타났다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.277-280
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• 2014

Background: Testicular cancer management is considered a marvel of modern science with excellent treatment results. Pakistan has a distinct ethnic variation and geographic distribution but data regarding clinical presentation of testicular tumors and their management is under reported. The objective of this study was to determine clinical profile, treatment modalities and survival outcome of testicular tumors in the Pakistani population. Materials and Methods: A retrospective review of patients who received treatment for testicular cancer at Shaukat Khanum Cancer Hospital from January 2009 to December 2012 was performed. Patient demographics, clinical features at presentation and treatment modalities were assessed. For categorical variables chi square test was used. Survival was calculated using Kaplan Meier survival curves and Log rank test was employed to determine significance. Results: The most common tumor was mixed germ cell tumor in 49% patients. For all tumor variants except seminoma, stage III was the most common clinical stage at presentation. Majority of patients with non seminomatous germ cell tumors presented in the15-30 year age group as compared to seminoma which was most prevalent in the 30-40 year age group. Orchiectomy followed by chemotherapy was the most common treatment modality in 80% patients. Expected 5 year survival for seminomas and non-seminomatous germ cell tumors was 96% and 90% respectively which was not significantly different (p=0.2). Conclusions: Despite a distinct clinical profile of testicular tumors in Pakistani population, survival is comparable with published reports.

• 한국정보통신학회논문지
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• 제20권4호
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• pp.739-746
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• 2016

철도 안전사고 예방을 목표로 하는 실시간 철도 안전관제 시스템에서는 DDS (Data Distribution Service) 표준 기술 기반의 데이터 전송 방안을 적용함으로 기존 현장의 안전검지장치로부터 발생한 데이터를 통합 및 관리하고 있다. 본 논문에서는 수많은 현장 데이터 중 일반철도 현장에서 발생한 신호설비 데이터 규격 설계를 소개하고 있다. 신호설비 데이터의 DDS 전송을 위하여 기존 표준 규격인 KRS SG 0062를 모델링하고, DDS 데이터 전송 단위인 Topic 설계 및 데이터 변환 방안을 제시하고, 데이터 성격 별로 네트워크 제어 QoS 정책 설계를 제시하고 있다. 또한 실제 현장 데이터를 분석하여 설계된 규격이 현장에 적용 가능한지를 확인해 보았다.

• 대한한의진단학회지
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• 제19권2호
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• pp.75-90
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• 2015

Objectives The purposes of this study was to develope a Qi gong exercise that suits characteristics of post mastectomy women, and to evaluate the effect of Qi gong exercise on immune response, blood circulation index, pulse wave parameter and heart rate variability. Methods This study was applied to total 35 post mastectomy women, including 17 for experiment group and 18 for control group. The Qi gong exercise was composed of total 24 times of 90 minutes per each time, twice a week, and 12 weeks and it was conducted by the oriental medicine professor who was an expert of Qi gong exercise. Results 1. Two group comparison revealed that the experimental group had significantly improved immune response(p<.021), HR(beats/min)(p<.001), ESV(ml/beat)(p=.038), ESI($ml/beat/m^2$)(p=.040), ECO (L/min)(p=.019), ECI($L/min/m^2$)(p=.023), ECRI($dyne^*sec/cm$)(p=.015), Left Kwan($div^3$)(p=.021), Right Kwan($div^3$)(p=.038), Mean HRV(cycle/min)(p<.001), SDNN(ms)(p=.043), RMSSD(ms)(p=.040), and TP(log $ms^2$)(p=.039). 2. Two group comparison revealed that the experimental group had significantly decreased ECR ($dyne^*sec^*cm^{-5}$) (p=.034), Left RAI(p=.044), Right RAI(p=.042), and pNN50(%)(p=.038). Conclusions These results from Qi gong exercise program can be used as basic data for development of health promotion program for Post Mastectomy Women.

• 디지털융복합연구
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• 제11권6호
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• pp.103-112
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• 2013

전통적인 방식의 예측모형 구축에서 사용되는 데이터는 주로 데이터베이스에 잘 보관되어 있는 정형데이터를 사용하였다. 하지만 지금의 상황은 스마트 시대의 도래로 인한 통신수단의 획기적인 발달로 비정형 데이터가 전체데이터의 80%를 상회하는 현실이다. 이러한 현실에서 기존의 방법대로 정형데이터 만을 이용하여 예측모형을 개발하면 예측모형의 신뢰성에 문제가 있을 것이다. 즉 전체데이터의 80%에 해당하는 비정형(SNS, 페이스북, 트위트, 이미지, 동영상 등)과 반정형(로그데이터)데이터를 반드시 포함하여 모형을 구축해야 만이 신뢰성을 현실화 시킬 수 있을 것이다. 본 논문에서는 예측모형 개발시 빅데이타 방법론을 적용하여 예측 모형의 신뢰성을 높이고, 데이터를 이용하여 제안된 방법과 전통적인 방법의 예측모형의 신뢰도를 비교 분석 하였다.

• 보건행정학회지
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• 제19권4호
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• pp.66-77
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• 2009

This study aims to examine the effect of socioeconomic status (hereafter, SES) on healthcare utilization of the patients with rare and incurable diseases. Information of 2,973 patients who were self-employed insured and utilized healthcare service in 2007 was drawn from the National Health Insurance (hereafter, NHI) claim data. SES was set as four groups based on the monthly contribution. Outcome variable was the expense for outpatient and in-hospital services, which was log-transformed and square-rooted in oder to obtain normal distribution. Covariates included age, gender, residence and diagnosis. To examine the effects after controlling for covariates, we employed generalized estimating equation model, since patients with the same diagnosis are likely to have similar characteristics of demographics and healthcare utilization. Univariate statistics showed that lower SES was associated with less utilization of healthcare services. After controlling for covariates, a significantly smaller amount of money was expended for the lowest SES group compared to the highest one. Rural residence was associated with less utilization, except that residents in Seoul significantly more utilized outpatient services in tertiary hospitals. Considering that there is a subsidy program for the low income patients, such differences in healthcare utilization according to SES seems to result from the burden of out-of-pocket payments for uncovered services of the NHI.