• Archives of Plastic Surgery
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• v.32 no.4
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• pp.461-466
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• 2005

Despite the major advances in the microvascular surgery with success rates of up to 98%, failure and vascular complications still remain even in the experienced hands. Failure of blood to flow across an anastomosis is usually caused by three factors: (1) Technical errors; (2) Undetected damage more proximally or via vasospasm; or (3) A clot or a thrombus. The success of a microvascular surgery depends on the severity of the vascular injury and, proper debridement of an injured vessel, and the failure rate of microvascular anastomosis in cases of trauma is higher as the thrombogenic possibility is increased by the endothelial damage. From January to November in 2003, 460 patients were underwent microvascular surgery(270 replantations and 190 free flap transfers) and re-operations were performed in 15 cases. Cases were reviewed by clinical and operative records. In these cases, causes of post-operative circulation insufficiency were identified as 9 vascular spasms and 6 thromboses at the previous anastomotic site. The average of re-operative success rate was 73%(60% in replantations and 100% in free flaps). In conclusion, through precise postoperative monitoring and assessment, immediate surgical re-exploration could be performed when a vascular complication is suspicious, the success rate of microvascular surgery would be increased more.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.255-261
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• 2018

Aglycon protopanaxatriol (APPT) has valuable pharmacological effects such as memory enhancement and tumor inhibition. ${\beta}$-Glycosidase from the hyperthermophilic bacterium Dictyoglomus turgidum (DT-bgl) hydrolyzes the glucose residues linked to APPT, but not other glycoside residues. ${\beta}$-Glycosidase from the hyperthermophilic bacterium Pyrococcus furiosus (PF-bgl) hydrolyzes the outer sugar at C-6 but not the inner glucose at C-6 or the glucose at C-20. Thus, the combined use of DT-bgl and PF-bgl is expected to increase the biotransformation of PPT-type ginsenosides to APPT. We optimized the ratio of PF-bgl to DT-bgl, the concentrations of substrate and enzyme, and the reaction time to increase the biotransformation of ginsenoside Re and PPT-type ginsenosides in Panax ginseng leaf extract to APPT. DT-bgl combined with PF-bgl converted 1.0 mg/ml PPT-type ginsenosides in ginseng leaf extract to 0.58 mg/ml APPT without other ginsenosides, with a molar conversion of 100%. We achieved the complete biotransformation of ginsenoside Re and PPT-type ginsenosides in ginseng leaf extract to APPT by the combined use of two ${\beta}$-glycosidases, suggesting that discarded ginseng leaves can be used as a source of the valuable ginsenoside APPT. To the best of our knowledge, this is the first quantitative production of APPT using ginsenoside Re, and we report the highest concentration and productivity of APPT from ginseng extract to date.

• Journal of Distribution Science
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• v.15 no.2
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• pp.91-100
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• 2017

Purpose - Domestic franchise market has been grown steadily, reaching 50 trillion won in sales and 3,360 franchise headquarters in 2014. A franchise system is an effective business system for the franchisees to lower the failure rate due to the fact that the inexperienced entrepreneurs are supported by their headquarters through the franchisee contract. However, there are also conflicts between franchiser and franchisee behind the quantitative growth of domestic franchise industry. Therefore, it is very important to structure the causes of conflicts and to examine the effect of factors on the relationship commitment and performances. Research design, data, and methodology - In this study, the author divides the composite incompatibility between the franchise and the franchisee into goal incongruity, domain dissensus, and perceptual differences, and examines each dimension to the relationship with commitment and performances. To verify the proposed research model and test hypotheses, the author selected 200 franchise responses in food and beverage industry. The data were analyzed using SPSS 18.0 and AMOS structural equation modeling program. Results - The empirical findings provide goal incongruity and perceptual differences have a negative effect on the affective commitment, but not the calculative commitment. In addition, affective commitment and calculative commitment are found to have a positive effect on re-contractual intention and extended brand shop running intention, respectively. Affective commitment have a stronger effect on re-contractual intention than calculative commitment. Conclusions - First of all, the fact that goal incongruity and perceptual differences negatively affect the affective commitment, but it does not affect the calculative commitment. It means the relationship commitment in distribution channel are multi-dimensional concept that may be attributed to emotional or affective dimensions but may exist in terms of necessity or power-dependence. Second, the level of relationship commitment such as affective and calculative commitment to franchise headquarters positively affects the re-contractual intention and franchiser's extend brand shop running intention suggest that franchiser should encourage and support existing franchisee's commitment. Third, the fact that affective commitment has a greater effect on relationship performance than calculative commitment means to induce franchisee's affective commitment and to prevent the inconsistency between goals and perceptual differences.

• The Journal of Industrial Distribution & Business
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• v.11 no.10
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• pp.75-89
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• 2020

Purpose: The container terminal is an area that plays an important role in the country's import and export. As the volume of containers increased worldwide, competition between terminals became fiercer, and increasing the productivity of terminals became more important. Re-handling is a serious obstacle that lowers the productivity of terminal. There are two ways to reduce re-handling in the terminal yard. The first method is to load containers in terminal yards using effective carry-in algorithms that reduce re-handling. The second method is to carry out effective remarshalling. In this paper, the performance of various carry-in algorithms and various remarshalling algorithms are reviewed. Next, we try to find the most effective combination of carry-in algorithm and remarshalling algorithm. Research design, data and methodology: In this paper, we analyze the performance of the four carry-in algorithms, AP, MDF, LVF, RP and the four remarshalling algorithms, ASI, ASI+, ASO, ASO+. And after making all the combinations of carry-in algorithms and remarshalling algorithms, we compare their performance to find the best combination. To that end, many experiments are conducted with eight types of 100 bays through simulation. Results: The results of experiments showed that AP was effective among the carry-in algorithms and ASO+ was effective among remarshalling algorithms. In the case of the LVF algorithm, the effect of carrying in was bad, but it was found to be effective in finding remarshalling solution. And we could see that ASI+ and ASO+, algorithms that carry out remarshalling even if they fail to find remarshalling solution, are also more effective than ASI and ASO. And among the combinations of carry-in algorithms and remarshalling algorithms, we could see that the combination of AP algorithm and ASO+ algorithm was the most effective combination. Conclusion: We compared the performance of the carry-in algorithms and the remarshalling algorithms and the performance of their combination. Since the performance of the container yard has a significant effect on the performance of the entire container terminal, it is believed that the results of this experiment will be effective in improving the performance of the container terminal when carrying-in or when remarshalling.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.7
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• pp.683-693
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• 2013

In this study, the mixing characteristics in lid-driven cavity flows were studied numerically by using a hybrid lattice Boltzmann method (HLBM). First, we compared the numerical results from single-relaxation-time (LB-SRT) and multi-relaxation-time (LB-MRT) models to examine their reliability. In most of the cavity flow, the results from both the LB-SRT and the LB-MRT models were in good agreement with those using a Navier-Stokes solver for Re=100-5000. However, the LB-MRT model was superior to the LB-SRT model for the simulation of higher Reynolds number flows having a geometrical singularity with much lesser spatial oscillations. For this reason, the LB-MRT model was selected to study the mass transport in lid-driven cavity flows, and it was demonstrated that mass transport in the fluid was activated by a recirculation zone in the cavity, which is connected from the top to the bottom surfaces through two boundary layers. Various mixing characteristics such as the concentration profiles, mean Sherwood (Sh) numbers, and velocity were computed. Finally, the detailed transport mechanism and solutions for the concentration profile in the cavity were presented.

• Journal of the Korean institute of surface engineering
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• v.36 no.5
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• pp.357-363
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• 2003

The aim of this work is the synthesis of a-C:H films from methane gas using surface spark discharge at the atmospheric pressure. Properties of these films have been investigated as functions of energy W delivered per a methane molecule in the discharge. The method enables the coatings to be deposited with high growth rates (up to $100 \mu\textrm{m}$/hour) onto large-area substrates. It is shown that the films consist of spherical granules with diameter of 20∼50 nm formed in the spark channel and then deposited onto the substrate. The best film characteristics such as minimum hydrogen-to-carbon atoms ratio H/C=0.69, maximum hardness $H_{v}$ =3 ㎬, the most dense packing of the granules and highest scratch resistance has been obtained under the condition of highest energy W of 40 eV. The deposited a-C:H coatings were found to be more soft and hydrogenated compared to the diamond-like hydrogenated (a-C:H) films which obtained by traditional plasmaenhanced chemical vapor deposition methods at low pressure (＜10 Torr). Nevertheless, these coatings can be potentially used for scratch protection of soft plastic materials since they are of an order harder than plastics but still transparent (the absorption coefficient is about $10^4$∼$10^{5}$ $m^{-1}$ At the same time the proposed method for fast deposition of a-C:H films makes this process less expensive compared to the conventional techniques. This advantage can widen the application field of. these films substantially.y.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.357-358
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• 2013

The non-linear characteristics of ON states are important for the application to the high density cross-point memory industry because the sneak current in neighbor cells occurred during reading, erasing, and writing process. Kw of above 20 in ON states, which is the writing current @ Vwrite/the current @ 1/2Vwrite, was required in cross-point ReRAM memory industry. The high current density non-linear IV curve of ZnSe selector was shown and the ALD HfO2 switching device has the linear properties of ON states and the compliance current of 100 uA. To evaluate the performance of the selection device, we connected itto HfO2 switching device in series. The bottom electrode of the selection device was connected to the top electrode of the RRAM. All of the bias was applied with respect to the top electrode of the selection device, whereas the bottom electrode of the RRAM was grounded. In the cross-point application, 1/2Vwrite and -1/2Vwrite were applied to the word-line and bit-line, respectively, which were connected to the selected cell, and a zero bias was applied to the unselected word-lines and bit-lines. The current @ 1/2Vwrite of the unselected cells was blocked by the selection device, thus eliminating the sneak path and obtaining a writing voltage margin. Using this method, the writing voltage margin was analyzed on the basis of the memory size.

• YAKHAK HOEJI
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• v.26 no.4
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• pp.239-251
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• 1982

The rate of deterioration of contractile force of isolated hearts from control and panax ginseng treated rats was determined and response of contractile force of the hearts from ginseng treated rats to several autonomic and other drugs was investigated. Rats weighing 150-250g were administrered orally with ginseng ethanol extract (100mg/kg) and total ginseng saponin (50mg/kg/day) for a week. Ginsenoside Rb$_{1}$ (5mg/kg/day) and ginsenoside Re (5mg/kg/day) were administered respectively for a week. The isolated hearts from rats were perfused with Krebs-Henseleit solution by using Langendorff perfusion apparatus. The control group was only able to maintain approximately 75.5% of their initial strength after 60 min of perfusion, whereas ginseng ethanol extract, total ginseng saponin treated hearts were able to sustain nearly their initial strength even after 60 min. Ginsenoside Rol treated hearts also sustained 93% of their initial strength, but there was no significant difference in the deterioration percentage of the contractile force of ginsenoside Re treated hearts. Experiments were conducted to study the response to perfusion of ginseng treated animal heart with epinephrine, isoproterenol, propranolol, and phenobarbital. The isolated hearts were perfused with Krebs-Henseleit solution containing epinephrine (10$^{-6}$ M), isoproterenol ($10^{-7}$M), propranolol ($10^{-6}$M) and phenobarbital (7{\times}10^{-3}M$) respectively. The maximum inotropic effect of epinephrine and isoproterenol was observed after 2~3 minutes of drug perfusion. Effect of epinephrine on ginseng ethanol extract and total ginseng saponin treated hearts was reduced compared with control. On the other hand, this phenomenon was not observed in ginsenoside Re treated rats but on ginsenoside $Rb_{1}$ treated rats. The positive inotropic effect of isoproterenol was reduced in the hearts from ginseng treated rats compared with control heart, Propranolol or phenobaribital decreased the contractile force in the control rats. The depressant effect of propranolol and phenobarbitat on ginseng treated rat hearts was less than those of control rat hearts. The result suggest that ginseng ethanol extract , ind total ginseng saponin and ginsenoside $Rb_{1}$ may protect the deterioration of contractile force of the heart and may attenuate the response to several drugs on hearts.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.2
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• pp.87-92
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• 2011

Objective: This study aimed to determine the safety and clinical effect of artificial shrinkage (AS) in terms of assisted hatching of fresh blastocysts. Also, we evaluated the correlation between patient age and the effect of AS on clinical outcome. Methods: Two AS methods, using a 29-gauge needle and laser pulse, were compared. Seventy-three blastocysts were shrunk using a 29-gauge needle and the same number of other blastocysts were shrunk by a laser pulse. We evaluated the shrunken blastocysts hourly and considered them viable if they re-expanded >70%. Blastocyst transfer cycles (n=134) were divided into two groups: a control group consisted of the cycles whose intact embryos were transferred (n=100), while the AS group consisted of the cycles whose embryos were replaced following AS (n=34). The implantation and pregnancy rates of the control group and AS group were compared ($p$ <0.05). Results: The re-expansion rates of the 29-gauge needle and laser pulse AS groups were similar (56 [76.7%] vs. 62 [84.9%], respectively). All of the remaining shrunken blastocysts were re-expanded within 2 hours. There was no degeneration of shrunken blastocysts. The total and clinical pregnancy rate of the AS group (23 [67.6%]; 20 [58.8%], respectively) was significantly higher than that of the control group (47 [47.0%]; 39 [39.0%], respectively). In the older patient group, there was no difference in the clinical outcomes between the AS and control groups. Conclusion: These results suggest that AS of blastocoele cavity, followed by the transfer, would be a useful approach to improve the clinical outcome in cycles in which fresh blastocyst stage embryos are transferred.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.165-165
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• 2013

희토류 발광 물질은 4f 껍질에 위치하는 전자의 독특한 특성 때문에 발광 소자와 디스플레이에 그 응용성을 확장하고 있다. 본 연구에서는 고효율의 적색과 주황색 형광체를 합성하기 위하여 모체 격자 CaNb2O6에 희토류 이온인 유로퓸과 사마륨을 치환 고용하여 최적의 합성 조건을 조사하였다. Ca1-1.5xNb2O6:REx3+ (RE=Eu, Sm) 형광체 분말 시료는 고상반응법을 사용하여 활성제 이온인 Eu3+와 Sm3+의 농도비를 0, 0.01, 0.05, 0.10, 0.15, 0.20 mol 로 변화시키면서 합성하였다. 초기 물질 CaO, Nb2O5, Eu2O3와 Sm2O3을 화학 적량으로 측정하고, 400 rpm의 속도로 24시간 밀링 작업을 수행한 후에, 건조기 $60^{\circ}C$에서 28시간 건조하고, 시료를 막자 사발에서 갈아 세라믹 도가니에 담아 튜브형 전기로에서 분당 $5^{\circ}C$의 비율로 승온시켜 $500^{\circ}C$에서 5시간 동안 하소와 $1,100^{\circ}C$에서 6시간 소결하여 합성하였다. Eu3+가 도핑된 경우에, 발광 스펙트럼은 Eu3+ 이온의 농도비에 관계없이 강한 적색 발광 스펙트럼이 616 nm에서 관측되었다. 이외에도, 596 nm와 708 nm에서 상대적으로 발광 세기가 약한 주황색 발광과 적색 발광 신호가 검출되었으며, 541 nm에서는 매우 약한 녹색스펙트럼이 관측되었다. Eu3+ 이온의 농도비에 0.01 mol에서 0.15 mol로 증가함에 따라 주발광 신호의 세기는 점점 증가하였으며, 0.15 mol에서 최대 발광 세기를 나타내었다. Eu3+ 이온의 농도비가 0.20 mol 로 더욱 증가함에 따라 주 피크의 세기는 농도 소강 현상에 의하여 현저히 감소함을 보였다. 한편, 주된 흡광 스펙트럼은 279 nm에서 나타났는데, 이것은 전하전달밴드 신호이다. Sm3+가 도핑된 형광체 분말의 발광 스펙트럼은 모든 시료의 경우에 613 nm에서 강한 적주황색 발광 스펙트럼이 관측되었고, 상대적으로 세기가 약한 570 nm와 660 nm에 피크를 갖는 황색과 적색 발광 스펙트럼이 발생하였다. 흡광과 발광 스펙트럼의 최대 세기는 0.05 mol에서 나타났으며, Sm3+ 이온의 농도비가 더욱 증가함에 따라 흡광과 발광 세기는 급격하게 감소하였다.