There always exist nonzero inspection errors whether inspectors are humans or automatic inspection machines. Inspection errors can be categorized by two types, type I error and type II error, and they can be regarded as either a constant or a random variable. Under the assumption that two types of random inspection errors are distributed with the “uniform” distribution on a half-open interval starting from zero, it was proved that inspectors overestimate any given fraction defective with the probability more than 50%, if and only if the given fraction defective is smaller than a critical value, which depends upon only the ratio of a type II error over a type I error. In addition, it was also proved that the probability of overestimation approaches one hundred percent as a given fraction defective approaches zero. If these critical phenomena hold true for any error distribution, then it might have great economic impact on commercial inspection plans due to the unfair overestimation and the recent trend of decreasing fraction defectives in industry. In this paper, we deal with the same overestimation problem, but assume a “symmetrical triangular” distribution expecting better results since our triangular distribution is closer to a normal distribution than the uniform distribution. It turns out that the overestimation phenomenon still holds true even for the triangular error distribution.

In this study, effects of nutrient and inorganic carbon on single cell emergence during the cultivation of microalgae were observed using colonial green algae, Pediastrum duplex. The concentration of inorganic carbon had significant effect on single cell emergence and its growth, but nitrogen and phosphorus concentration showed minor effects. According to P. duplex cultivation experiment, single cell started to be emerged around 500~750 mg-C/L of inorganic carbon concentration and it was bloomed dramatically at the higher values. And growth of P. duplex was started to be surpressed at the single cell formation concentration. From the results, it could be said that when we operate the microalgae systems for cultivation/harvesting or wastewater treatment, in order to avoid single cell formation, inorganic carbon should be maintained to the proper level

This study investigated the effect of high concentration of free ammonia on microalgal growth and substrate removal by applying real wastewater nitrogen ratio. To test of this, the conditions of free ammonia 1, 3, 6, 9, 12, 15 mg-N/L are compared. After 3 days of incubation, algal growth of Chlorella vulgaris and carbon removal rate are respectively lower in the reactors of FA 12, 15 mg-N/L compared to the others. This indicates that the high concentration of free ammonia, in this case, above 12 mg-N/L, has negative effect on algal growth and metabolic activity. Also, high concentration of free ammonia causes the proton imbalance, ammonium accumulation in algae and has toxicity for these reasons. So, we have to consider free ammonia in applying the microalgae to wastewater treatment system by the way of diluting wastewater or controlling pH and temperature.

Although microalgae are considered as a promising feedstock for biofuels, cost-efficient harvesting of microalgae needs to be significantly improved. In this study, the use of electro coagulation as a more rapid flocculation method for harvesting a freshwater (Scenedesmus dimorphus) microalgae species was evaluated. The results showed that, electro coagulation was shown to be more efficient using an aluminum anode than using an iron anode. And optimum conditions of electro coagulation for harvesting Scenedesmus dimorphus were found. The optimum stirring speed was 100 rpm and optimum pH was 5. Furthermore, the current density which the fastest and highest recovery efficiency is achieved at 30 A/m2, while the highest energy efficiency was achieved at 10 A/m2. A the rapid and high recovery efficiency indicate that electro coagulation is a particularly attractive technology for harvesting microalgae.

제주도 숨은물벵뒤 습지에서 Betaproteobacteria의 종다양성을 조사하였고, 신분류군 후보 22균주를 확보하였다. 분리주의 16S rRNA 유전자 염기서열을 분석한 결과Burkholderiaceae (3균주), Comamonadaceae (8균주), Oxalobacteraceae (5균주) 및 Neisseriaceae (5균주) 등 4개 과에 속한 15속, 그리고 소속 미상의 Burkholderiales 소속1속(1균주)으로 동정되었다. Chr

본 연구에서 처리수를 이용한 주기적인 역세척은 세라믹 정밀여과에 의한 고도정수처리 시스템에서 막오염을 저감하고 투과선속을 향상시키고자 수행되었으며, 물 역세척 주기(FT) 및 시간(BT)의 영향과 최적 운전조건을 규명하고자 하였다. FT의 영향을 알아보기 위해 일정한 BT 3초에서 FT를 30∼120초로 변화시켰고, BT 영향 실험에서 일정한 FT 120초에서 BT를 3∼12초로 변화시켰다. 그리고 다른 운전변수인 막간압력차는 1.52 bar, 물 역세척 압력 0.98 bar, 유입유량 0.5 L/min, 공급액의 온도 20℃로 일정하게 유지하였다. 그 결과, 일정한 BT 3초에서 본 실험 범위의 최적 FT는 30초로, 이것은 빈번한 역세척이 막오염의 저감에 더 효과적임을 의미한다. 그러나 너무 짧은 BT로 인하여 FT의 영향은 크지 않았다. 한편, 일정한 FT 120초에서 BT가 증가함에 따라 막오염에 의한 저항(Rf)은 감소하고 투과선속(J)과 무차원화한 투과선속 (J/Jo)은 증가하는 경향을 나타내어, 최대 BT인 12초에서 가장 많은 총여과부피(VT)를 얻을 수 있었다.

Laparoscopy is frequent used to assist the diagnosis and treatment of various surgical department. However, complications associated with the procedure including pneumothorax, pneumomediastinum, subcutaneous emphysema, pneumopericardium, and air embolism have been reported. Incidence of subcutaneous emphysema during extraperitoneal laparoscopic surgery has been reported 99%. We report the case of a 76 years old female patient who had subcutaneous emphysema and hypercarbia during retroperitoneal laparoscopic nephrectomy. After developing hypercapnia, we increased the minute ventilation and lowered the CO2 gas insufflation pressure. Until the end of the operation, the patient’s vital signs did not change and end tidal CO2 was not increased any more.

This is the case report of a 58-year-old man who developed acute severe hypoglycemia after a spinal block. He had a history of injecting insulin combined with 50% dextrose for hyperkalemia control. After the spinal block, he presented with hypo-glycemic symptoms and went into convulsions. Following injection of midazolam and 10 ml of 50% dextrose, his mental state returned to alert. We recommend careful monitoring of blood sugar level of chronic kidney disease patients who under-go neuraxial block.

최근 입출항 수속 간소화에 대한 관심이 증대되면서 국제해사기구의 간소화 위원회를 중심으로 입출항 수속 절차와 신고서식의 표준화 작업이 진행되고 있다. 또한 항만 선진국에서는 전자적 수단을 이용하여 입출항 수속을 간소화함으로써 입출항 정보의 원활한 흐름과 효율화를 증대시키는 연구가 활발히 진행되고 있다. 입출항 수속 간소화 문제는 개별 단위국가의 노력으로는 한계가 있고, 관련 국가들간의 협력을 통해 원만히 해결 될 수 있다. 이에 따른 입출항 수속과 관련한 신고서식 및 절차의 표준화와 정보의 통합화가 선행되어야 한다. 먼저 본 연구에서는 입출항 수속 간소화에 대한 국세동향 분석을 통해 선진항만에서 이루어지고 있는 간소화 사례를 살펴보았다. 다음으로 한·중·일 3국을 중심으로 동북아 항만의 입출항 수속현황과 신고서식을 분석하여 공통적인 문제점을 도출하였으며 이를 해결하기 위한 방안으로 ebXML 기반에 국제 항만 입출항 신고 시스템을 제안하였다. 본 프레임워크를 통해 입출항 수속 정보의 재사용과 신고의 자동화가 가능해 짐으로써 간소화를 실현할 수 있으며, 항만산업에 전자상거래를 도입할 수 있는 기반을 마련하였다.