• 한국간담췌외과학회지
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• 제28권2호
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• pp.115-124
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• 2024

To compare the outcomes of low central venous pressure (CVP) to standard CVP during laparoscopic liver resection. The study design was a systematic review following the PRISMA statement standards. The available literature was searched to identify all studies comparing low CVP with standard CVP in patients undergoing laparoscopic liver resection. The outcomes included intraoperative blood loss (primary outcome), need for blood transfusion, mean arterial pressure, operative time, Pringle time, and total complications. Random-effects modelling was applied for analyses. Type I and type II errors were assessed by trial sequential analysis (TSA). A total of 8 studies including 682 patients were included (low CVP group, 342; standard CVP group, 340). Low CVP reduced intraoperative blood loss during laparoscopic liver resection (mean difference [MD], -193.49 mL; 95% confidence interval [CI], -339.86 to -47.12; p = 0.01). However, low CVP did not have any effect on blood transfusion requirement (odds ratio [OR], 0.54; 95% CI, 0.28-1.03; p = 0.06), mean arterial pressure (MD, -1.55 mm Hg; 95% CI, -3.85-0.75; p = 0.19), Pringle time (MD, -0.99 minutes; 95% CI, -5.82-3.84; p = 0.69), operative time (MD, -16.38 minutes; 95% CI, -36.68-3.39; p = 0.11), or total complications (OR, 1.92; 95% CI, 0.97-3.80; p = 0.06). TSA suggested that the meta-analysis for the primary outcome was not subject to type I or II errors. Low CVP may reduce intraoperative blood loss during laparoscopic liver resection (moderate certainty); however, this may not translate into shorter operative time, shorter Pringle time, or less need for blood transfusion. Randomized controlled trials with larger sample sizes will provide more robust evidence.

• 한국경영과학회지
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• 제16권1호
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• pp.13-34
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• 1991

A production/inventory system is considered in which a production facility produces one type of product. The demand for the product is given by a compound Poison process and is supplied directly from inventory when inventory is available and is lost when inventory is out of stock. The processing time to produce one item is assumes to follow a general distribution. An (s, S) policy is considered in which production stops at the instant the stock on hand reachs S and the setup of the production facility begins at an inspection point when the stock on hand drops to or below s for the first time. The time interval between two successive inspection points during a non-production period is a random variable which follows a general distribution.

• 한국주거학회논문집
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• 제23권1호
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• pp.27-41
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• 2012

The objective of this study is to develop the blind control strategy and method which reduce negative effect of incoming daylight on visual comfort of occupants, minimize psychological anxieties caused by frequent motions of a blind, and maximize positive effect of incoming daylight and solar irradiation by opening/closing of a blind. As previous researches on blind controls have limited outdoor environmental conditions to those in specific regions, orientations and dates, these resulted in problems at various conditions for general-purpose application. Major problem is that the time interval and amount of blind movement do not meet the control objective at the end of control zone and discontinuous curve. To overcome these limitations revealed in the previous researches, following tasks were performed in this study. 1) To establish the control objective to accomplish the goal of this study. 2) To develop the control methods and algorithms which prevent glare on the work-plane at any time and which control the time interval and amount of blind movement to follow the control objective at various profile angle curves. 3) To validate the general-purpose applicability and performance of the developed control methods and algorithms by simulation and its data analysis at various conditions. It was found that the proposed methods and algorithms can prevent the direct glare on the work-plane at all the time and also increase the incoming daylight and solar irradiation.

• Journal of Korean Neurosurgical Society
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• 제59권5호
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• pp.498-504
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• 2016

Objective : Although subdural hematoma (SDH) is commonly treatable by burr hole surgery in the late subacute or chronic stage, there is no clear consensus regarding appropriate management and exact predictive factors for postoperative recurrence also remain unclear. The aim of this study was to evaluate risk factors associated with recurrence of SDH that requires burr hole surgery in the late subacute or chronic stage. We also identified the appropriate timing of surgery for reducing the recurrence. Methods : We retrospectively reviewed 274 patients with SDH in the late subacute or chronic stage treated with burr hole surgery in our hospital between January 2007 and December 2014. Excluding patients with acute intracranial complications or unknown time of trauma onset left 216 patients included in the study. Results : Of 216 patients with SDH in the late subacute or chronic stage, recurrence was observed in 36 patients (16.7%). The timing of the operation in patients with late subacute stage (15-28 days) resulted in a significant decrease in recurrence (RR, 0.33; 95% CI, 0.17-0.65; p=0.001) compared to chronic stage (>28 days). Otherwise, no significant risk factors were associated with recurrences including comorbidities and surgical details. Conclusion : The results indicated that time from trauma onset to burr hole surgery may be important for decreasing the risk of recurrence. Therefore, unless patients can be treated conservatively without surgery, prompt surgical management is recommended in patients diagnosed as having late subacute or chronic subdural hematoma treatable by burr hole surgery, even when neurological deficits are unclear.

• 한국정보통신학회논문지
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• 제24권7호
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• pp.885-890
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• 2020

거리측정 시스템에서 사용되는 시간-디지털 변환회로는 시작신호와 멈춤신호 사이의 시간 간격을 이용하여 거리를 측정한다. 응답속도를 고려한 시간 간격은 일반적으로 카운터 회로를 이용하여 디지털 정보로 변환한다. 그러므로 정밀도 향상을 위해서는 높은 주파수의 클록 신호가 요구되며, 미세 거리의 측정을 위해서도 높은 주파수의 클록 신호가 필요하다. 본 논문에서는 동일한 주파수를 사용하면서도 거리 측정의 정밀도를 높이기 위한 카운터 회로를 설계하였다. 회로의 설계는 0.18㎛ CMOS 공정을 이용하였으며, 설계된 회로의 동작은 HSPICE 시뮬레이션을 통하여 확인하였다. 시뮬레이션 결과 일반적인 카운터 회로를 사용한 경우에 비해 4배의 향상된 정밀도를 얻을 수 있었다.

• Clinical and Experimental Vaccine Research
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• 제12권4호
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• pp.337-345
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• 2023

Purpose: The global fight against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has led to widespread vaccination efforts, yet the optimal dosing schedule for SARS-CoV-2 vaccines remains a subject of ongoing research. This study aims to investigate the effectiveness of administering two booster doses as the third and fourth doses at different intervals to enhance vaccine protection. Materials and Methods: This study was conducted at a military regional hospital operated by the Ministry of National Defense in Taiwan. A cohort of vaccinated individuals was selected, and their vaccine potency was assessed at various time intervals following their initial vaccine administration. The study participants received booster doses as the third and fourth doses, with differing time intervals between them. The study monitored neutralizing antibody titers and other relevant parameters to assess vaccine efficacy. Results: Our findings revealed that the potency of the SARS-CoV-2 vaccine exhibited a significant decline 80 days after the initial vaccine administration. However, a longer interval of 175 days between booster injections resulted in significantly higher neutralizing antibody titers. The individuals who received the extended interval boosters exhibited a more robust immune response, suggesting that a vaccine schedule with a 175-day interval between injections may provide superior protection against SARS-CoV-2. Conclusion: This study underscores the importance of optimizing vaccine booster dosing schedules to maximize protection against SARS-CoV-2. The results indicate that a longer interval of 175 days between the third and fourth doses of the vaccine can significantly enhance the neutralizing antibody response, potentially offering improved protection against the virus. These findings have important implications for vaccine distribution and administration strategies in the ongoing battle against the SARS-CoV-2 pandemic. Further research and largescale trials are needed to confirm and extend these findings for broader public health implications.

• Journal of applied mathematics & informatics
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• 제28권1_2호
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• pp.1-11
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• 2010

The conditional covering problem is an important variation of well studied set covering problem. In the set covering problem, the problem is to find a minimum cardinality vertex set which will cover all the given demand points. The conditional covering problem asks to find a minimum cardinality vertex set that will cover not only the given demand points but also one another. This problem is NP-complete for general graphs. In this paper, we present an efficient algorithm to solve the conditional covering problem on interval graphs with n vertices which runs in O(n)time.

• 한국응급구조학회지
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• 제16권1호
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• pp.81-90
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• 2012

Objectives: This study is to research delay time comparison for later defibrillation after hands off according to the changes in defibrillation electrodes. Study purpose: In defibrillation treatment that is the only way for cardiac arrest by arrhythmia, it is to find defibrillator device which can minimize late defibrillation delay time after important affect of hands off. Study object and method: After hands off according to the defibrillator device, we collected total 40 people for emergency medicine doctor, internal medicine doctor, general surgeon, nurse, emergency medical technician who are working at 2 CN, CS University hospitals in Gwangju Jeollanamdo district to find out hand off shock interval(HOSI). We then researched their general properties like occupation sector, experiences in clinic, gender, completion of AHA ACLS-P training and more. Then 40 participants continued ventricular fibrillation cardiac arrest simulation training (using human-model mannequin) designed by researcher and performed their roles as defibrillation operator. Each of participant used manual paddle and performed 4 times of defibrillation (150J) during 8 minutes of CPR and in 8day, the defibrillator devices were replaced from manual paddle to self-adhesive electrodes pads and 4 times of defibrillation (150J) under same simulation condition as manual paddle were performed. Study result: In comparison for delay time of later defibrillation after hands off of manual paddle and self adhesive electrodes pad, the self adhesive electrodes pad ($7.0{\pm}0.5sec$) seemed to reduce delay time of later defibrillation significantly (p<0.05) compared to manual paddle ($10.0{\pm}0.9sec$). The self adhesive electrodes pad, according to the general properties of participants, had no particular change in delay time after later defibrillation for the statistics (p>0.05) but the manual paddle had statistically significant differences for the occupation sector, experiences in clinic and gender (p<0.05). Conclusion: In defibrillation, the self adhesive electrodes pad($7.0{\pm}0.5sec$) showed short HOSI compared to manual paddle ($10.0{\pm}0.9sec$) significantly (p<0.05) and it applied identically for both existence and non-existence of ACLS-P training completion, experiences in clinic, gender and occupation sector. The manual paddle had also significant difference in experiences in clinic and occupation sector (p<0.05). which means the effect on HOSI according to the job mastery. Therefore, if the clinic experience is short or in case for the occupations without frequent defibrillation treatment has a danger of lowering success rate for the defibrillation using manual paddle. Therefore, it is true that using self adhesive electrodes pad for defibrillation electrodes when performing manual defibrillation in pre-hospital as well as in-hospital steps can generally minimize delay time of later defibrillation after hands off.

• 대한임상검사과학회지
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• 제41권2호
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• pp.62-66
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• 2009

HbA1c is the major fraction of glycated hemoglobin, and used primarily to identify the average plasma glucose concentration over prolonged periods of time, mostly 2-3 months. It is used as markers for the diagnosis and monitoring of diabetic patients and increasingly used a marker in health screening check up for general populations. In this study, HbA1c was measured with Cobas integra 800 (Roche Diagnostics, Mannheim, Germany), using immunoturbidimetry principles. We established the reference interval for HbA1c with Cobas integra 800 and evaluated its significance. The study subjects were 36,140 (male 57.5%, and female 42.2%) who visited the Health Promotion Center of a tertiary care center in Seoul for health checkup from January to September, 2008. HbA1c levels were measured with immunoturbidimetric method. Statistical evaluation was done with SPSS. Comparison between male and female was checked with Mann-Whitney test, and among age groups with Kruskal-Wallis test. Reference interval for HbA1c was from 4.8% to 6.1%. There was no significant difference between male and female with Mann-Whitney test (P=0.539). There was significant difference among age groups with Kruskal-Wallis test (P<0.05). Reference interval for HbA1c with Cobas integra 800 was 4.8~6.1%, which was different from conventional one, 4.4-6.4%. Establishment of reference interval for each principle is needed.

• 한국수자원학회논문집
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• 제42권6호
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• pp.457-464
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• 2009

본 논문에서는 상수관로의 파손자료를 이용하여 관로의 위험률을 산정하기 위해 사용되는 비례위험모형의 관로의 순차적 파손시간 예측정확도를 분석하고 이를 이용하여 관로의 경제적 교체 시간구간을 산정할 수 있는 방법론을 제시하였다. 비례위험모형에 기초한 생존함수를 이용하여 연구대상 관로들의 순차적 파손시간을 예측하고 이들을 기록된 파손시간과의 차이를 분석하였다. 이를 통하여 비례위험모형의 파손시간 예측 오차를 최소화하는 생존확률은 0.70인 것으로 결정되었으며, 세 번째 파손으로부터 일곱 번째 파손에 대한 모형만이 관로의 파손시간을 예측하는데 적합한 것으로 분석되었다. 생존확률 0.70과 순차적 파손사건에 대한 생존함수의 하한 및 상한을 이용하여 예제로 사용된 관로에 대해 예측된 파손시간의 95% 신뢰구간의 하한 및 상한을 추정하였다. 예측된 파손시간의 95% 신뢰 구간의 하한과 상한을 이용하여 관로 파손 경향모형인 General Pipe Break Prediction Models(GPBM)을 구축하고 이들을 관로의 한계파괴율과 결합하여 시간에 대한 해를 구하므로써 경제적 교체 시간구간을 산정하였다.